Survey Glossary

Access
Property should always have proper access to a public highway, otherwise it may be landlocked.

It cannot always be assumed that a road or path adjoining a property is a public highway, and a buyer's Conveyancing Solicitor will check this with the local authority as part of the local searches.

If a property does not directly abut a public highway, it should have the benefit of a right of way over neighbouring property leading to a public highway. Many properties as well as fronting a public highway have the benefit of a private rear road or path, to allow access to the garden or garage.

The buyer's Conveyancing Solicitor will check with the deeds for the existence of legal rights of way. However the buyer's Surveyor should also be asked to comment on the condition of any access way and to confirm that it can be used and has not been obstructed.

If access is limited in any way this might affect the value of the property, and the Surveyor should be asked to advise. For example, a property might only be accessible on foot and have no vehicular access.

Disputes over access can be lengthy and costly, so it is best to avoid buying a property where there is any ongoing access problem.

Houses on many modern developments are grouped around small courtyards or cul-de-sacs which are not publicly maintained. In these cases each property should have a right of way over the shared access way, and the deeds should contain provisions detailing who is responsible for its maintenance and repair.

When a property owner is liable to contribute to maintenance costs for a private access, a Surveyor's advice should be obtained as to the likelihood of work being required in the near future.

If a property is subject to a right of access for the benefit of a neighbouring property a buyer should be informed of this by his Conveyancing Solicitor. A Surveyor's advice may be required as to whether this will affect the property value.

Adverse Possession
Adverse possession is when someone occupies property or land which they do not own without the true owner's permission, they are in adverse possession of it.

In certain circumstances a person who stays in adverse possession for long enough can claim 'possessory title' and the original owner's title will be extinguished.

Even when someone in adverse possession cannot claim possessory title it can be difficult to get them evicted and it will often be necessary to go to court.

For these reasons it is important when buying property to make sure that there is no-one in adverse possession. Sellers should be asked to confirm who is in occupation of the property, and the basis of their occupation.

When buying a property with vacant possession it is important to make sure that no-one stays in occupation after completion. So any adult who lives in the property but whose name is not on the title register should be asked to sign the contract to confirm that they will vacate the property at completion.

If a property is being bought subject to an existing tenancy, enquiries should be made to confirm that the tenants have not unlawfully sub-let or allowed anyone else into occupation.

Another point to watch when buying a property is to check that the position of the boundaries on the ground agrees with the title plan - sometimes fences are moved and a neighbour may be in adverse possession of part of the property. If in doubt get a Surveyor to carry out a check.

If you find that the seller of a property only has possessory title then your Conveyancing Solicitor will advise you on the consequences.

Aggregate
Aggregates are sand, gravel, crushed rock and other similar materials used in building construction. In house construction, aggregates are commonly mixed with cement and water to form concrete.

Loose aggregate such as gravel is also used to provide a bed for foundations and when laying soil drains and water pipes in the ground. Aggregates are mostly obtained from quarrying and dredging from the sea and rivers, but a significant proportion in the UK now consists of recycled material, such as crushed concrete and geosynthetic aggregates produced from recycled plastic.

Air Brick
Air bricks are bricks with holes through them, designed to allow air to pass though. They are inserted in exterior walls to provide ventilation of Cavity Walls and spaces below floors so as to prevent the build-up of damp, mould and unwanted and hazardous gases (such as Radon).

Air bricks must not be allowed to become blocked. A survey will show if this has happened, and what remedial work is required. Often this will be fairly simple, such as removing a build-up of soil, but if later building work has blocked an air brick then more extensive work may be required.

The ground floor of older houses frequently consists of a timber floor suspended on joists, with a space or void beneath. Ventilation to this area by means of air bricks is essential, as otherwise the timber joists and flooring will be prone to rot and fungal infection.

Air bricks are also frequently found in older properties to provide room ventilation. Such ventilators are often blocked with paper to stop draughts. This can cause problems with damp. especially in bathrooms and kitchens.

Amosite
Amosite is a trade name for a type of asbestos mined in South Africa. (The name is derived from the initials of asbestos mines of South Africa" with the addition of "-ite".)

Amosite is commonly known as "brown asbestos" and was widely used as a fire retardant in thermal insulation products, like ceiling tiles. Its use in the UK is now banned, but it can still be found in older homes.

This form of asbestos is said to be "highly friable" which means it crumbles easily when damaged. Airborne fibres may then be released which can be inhaled by people in the vicinity.

Amosite is considered to be one of the more hazardous forms of asbestos. If building work is to be done on a property containing this material great care must be taken either to ensure that it is not damaged, or that any material is removed by properly qualified contractors.

A building survey may indicate if a property is likely to contain asbestos products, in which case a further specialist survey may be required.

Architect
An architect is someone who designs houses and other buildings, drawing the necessary plans and specifications to enable builders to construct the building. An architect may also be involved when alterations are carried out on an existing building, e.g. when a factory or warehouse is converted into residential apartments.

Architects will oversee construction or alteration works to ensure that everything is done in accordance with the plans and specifications. When the work is completed to the architect's satisfaction a certificate of practical completion will be issued.

In the UK architects must be registered with the Architects Registration Board (ARB). The ARB was established under the Architects Act and has the following functions:

• Prescribing the qualifications needed to become an architect
• Keeping the UK Register of Architects
• Ensuring that architects meet our standards for conduct and practice
• Investigating complaints about an architect's conduct or competence
• Making sure that only people on our register offer their services as an architect.

Architects may also belong to the Royal Institute of British Architects (RIBA.) 

When a mortgage is required on a new-build home, or one which has been constructed or converted within the previous six years, and which does not have the benefit of an NHBC or similar warranty, lenders generally require confirmation that a Professional Consultant's Certificate has been issued in respect of the property.

This certificate can be given by a registered Architect, and will confirm that he or she has overseen the construction work, and has professional indemnity insurance in force.

Architrave
An architrave is a strip of wood (usually) or moulding surrounding a door or window frame, covering the join between the frame and the plaster or other surface finish of the surrounding wall. Architraves are usually made of wood but other materials such as plaster, MDF or UPVC are also used.

Architraves provide a decorative finish to doorways but do not have any structural function. They are therefore unlikely to be a significant item on a survey report. Replacing damaged timber architraves can generally be done easily; repairing or replacing architraves in period properties may require an expert craftsman, but specialist companies provide a wide range of architrave mouldings in period designs.

(in classical architecture, an architrave is a stone beam or lintel resting on two columns.)

Artex
Artex is the trademark name of an interior decorative finish manufactured by Artex Ltd. The name is also used generically to describe similar products.

It is usually applied to ceilings, and given a textured finish while still wet. A simple stippled finish is easy to produce, but a variety of decorative patterns can also be produced. Variations including whorls or wavy lines have been popular in the past.

Artex has been widely applied over plaster ceilings in older houses, where its ability to cover cracks enabled a ceiling to be easily renovated. It was also popular in newly built homes where it could be applied straight over plasterboard ceilings, covering the joins in the boards. Until the mid-1980s Artex contained white asbestos. This may not be a health hazard, unless attempts are made to remove it by sanding or the coated ceiling or wall is being removed. If asbestos is present then removal and disposal should be carried out by a licensed contractor. It is therefore often better to cover the Artex with a skim-coat of plaster, provided it is sound.

The existence of an Artex finish is apparent from visual inspection but, unless the homeowner knows exactly when the finish was applied, it would be necessary for a specialist survey to be carried out to discover if asbestos is present.

Article 4 Directions
A local planning authority can make a Direction under Article 4 of the Town and Country Planning (General Permitted Development) Order 1995, excluding the application of the Order to a particular property or area.

The effect of this is that the owner of an affected property will not be able to carry out works which would otherwise be Permitted Development without first obtaining planning consent.

Article 4 Directions are commonly applied to Conservation areas.

They are also frequently applied as a planning condition on new housing developments.

This will be revealed on local searches carried out by buyers' Conveyancing Solicitors.

Asbestos
During a HomeBuyer Report of Building Survey, the surveyor does not carry out an asbestos inspection and does not act as an asbestos inspector when inspecting properties that may fall within the Control of Asbestos Regulations 2006. With flats, the surveyor assumes that there is a 'dutyholder' (as defined in the regulations), and that in place are an asbestos register and an effective management plan which does not present a significant risk to health or need any immediate payment. The surveyor does not consult the dutyholder.

Asbestos is a fibrous material obtained from a number of silicate minerals (rocks formed out of silica). Because of their crystalline structure long strands of fibres can be drawn out from these minerals, which can be woven or incorporated into other materials. Asbestos is naturally fire-resistant - the name derives from an ancient Greek word meaning 'inextinguishable' - and has excellent insulation properties. This made it a popular material for use in housing construction for a wide variety of purposes.

Unfortunately the inhalation of asbestos causes lung diseases (asbestosis) and cancer. This has now led to prohibition of the extraction, manufacture and use of asbestos and asbestos products in the UK and throughout Europe.

Asbestos was used in the construction of houses from the early nineteenth century through to the latter part of the twentieth century. It was often mixed with concrete and PVC to make tiles and roofing sheets. Uses included:

• lagging boilers and pipes
• water tanks
• boiler flues
• roof tiles
• corrugated roof sheets
• thermoplastic and vinyl floor tiles
• heat and sound insulation boards (AIB)
• ceiling panels
• electrical insulation
• decorative finishes

The use of most types of asbestos in buildings was prohibited in 1985, but some types were not finally prohibited until 1999. Because of its wide range of uses it is likely that most homes constructed before 1985 will contain asbestos in some form, and it may also be found in properties built between 1985 and 1999. (see for pictures.)

It is the inhalation of asbestos fibres which causes disease, so generally speaking the existence of asbestos in older properties does not create a health hazard unless there is any likelihood of fibres being released. This can happen when materials containing asbestos become damaged or are being removed. For this reason the removal and disposal of asbestos-containing materials is now governed by strict regulations, with substantial penalties for failing to comply. (the Control of Asbestos Regulations 2012)

A home survey report will indicate probable existence of asbestos where this is evident, e.g. roof tiles. However asbestos-containing materials will often be covered by decorative finishes, and their existence can only be discovered by a specialist survey.
Homebuyers may also consider requesting an environmental survey which could reveal the existence of former factories in the vicinity which processed asbestos.

Sound, undamaged and non-fibre-releasing asbestos should not be disturbed, and its condition should be regularly monitored. If the asbestos-containing material is in good condition and is unlikely to be damaged during normal use of the building, it is safer to leave it in place.
If refurbishment or alterations to a pre-21st century home are planned, an asbestos survey should be carried out before work commences. If necessary, asbestos removal and disposal must then be undertaken by specialist contractors.

The existence of asbestos can be a major problem in blocks of flats, especially those owned or originally built by local authorities. Its removal may necessitate occupiers being required to vacate their property while removal is carried out. Owners will also be required to contribute to removal cost in their service charges.

Asbestos was derived from a number of minerals, and there are several varieties found which include:

• actinolite
• amosite
• anthophyllite
• chrysotile
• crocidolite
• tremolite

The different types were more commonly classified as 'blue', 'brown' and 'white' asbestos.

Asbestosis
One of a number of diseases caused by breathing asbestos dust and fibres. Asbestosis is a form of fibrosis, or scarring of the lungs. This causes severe breathlessness, heart failure and an increased risk of lung cancer mesothelioma. There is no treatment to alter the progression of the disease; sufferers undertake courses of oxygen therapy and physiotherapy to mitigate symptoms.

The use of asbestos in the building industry has been banned for some years. However builders and tradesmen such as plumbers and electricians who may have previously worked with asbestos-based products are still at risk of contracting this disease. Anyone who has been exposed to asbestos via work, home or environment should notify their doctors about exposure history. This would include anyone who lived near a factory manufacturing asbestos-based products before they were banned.

Attic Conversion
If an attic or loft is converted into a liveable space, such as a bedroom, Building Regulations approval is required. However planning consent is only required if the conversion will extend or alter the roof space, and it exceeds specified limits and conditions.

When buying a house with an existing attic conversion, it will be necessary to ascertain when the work was carried out and whether the necessary consents were obtained. This is often difficult if work was carried out by an earlier owner, and it may be necessary for an indemnity insurance policy to be obtained to cover any loss if the local authority takes enforcement action for removal of the conversion.

If a conversion has been carried out without building regulation consent, there is a danger that the work may have weakened the existing structure of the building, especially the roof. A building survey may indicate the existence of a conversion, and may state if a further detailed inspection is required (e.g. if the roof structure has been hidden by conversion works.)

Attics or lofts are often used as storerooms or workrooms, and the floor may have been boarded and roof windows inserted. This does not require any consent provided that the attic is not used as a liveable space.

Balanced Flue
Balanced flues are designed to allow gas and other types of fire to burn fuel in a sealed chamber. They consist of concentric pipes, i.e. one pipe within a larger pipe. The air necessary for combustion is drawn through one pipe, and carbon monoxide and other waste gases are discharged through the other pipe. so avoiding direct contact between combustion and the air in a room.

A balanced flue connects from the fire or boiler to the outside air, passing through the external wall of a property. While the location of the flue can be quite flexible, gas regulations stipulate that the external end must be placed in such a position that carbon monoxide is not drawn back into the building through open windows, doorways or other ventilators.

The use of balanced flues enables boilers and fires to be installed in properties without requiring traditional chimneys, and also enables modern boilers to be installed in older homes without needing to connect into an existing chimney.

The flue must not be allowed to become blocked in any way, nor must there be any leakage of carbon monoxide from the flue into the interior if a house. A building survey will indicate if there is any obvious damage to the flue or if it is wrongly positioned, but a full test of the gas system may be required to show if the flue is functioning properly.

Ball Valve
The term Ball Valve is often applied to the device more properly known as a float valve, or ballcock.

Ball or float valves are used to regulate the flow of water into a tank, such as a toilet cistern. When the toilet is flushed, the valve opens to allow more water into the cistern until it reaches a certain level, at which point the valve is closed.

The valve is operated by means of a lever attached to the valve; at the other end of the lever a hollow ball or cylinder is attached, which floats on the water. When the water level falls the floating ball allows the lever to drop, causing the valve to open and water to be admitted. As more water flows into the tank the float is pushed upwards until the valve shuts once the water reaches a suitable level.

Should the valve fail to shut off the water properly, an overflow pipe will carry water outside the house to prevent flooding. If water is seen to be leaking from such an overflow pipe the valve should be adjusted or renewed as necessary.

The term 'ball valve' also describes a type of valve in which a sphere with a hole or port through its centre allows water (or other fluids) to flow when the port is in line with the inlet and outlet of the valve, but will shut off the flow when the ball is turned within the body of the valve. Such valves are suitable where the water supply only needs to be shut off occasionally, such as to allow a washing machine or dishwater to be disconnected from the main water supply.

Ball valve repairs are generally straightforward, and a property surveyor will advise if more fundamental issues with the cistern or general plumbing are suspected.

Baluster
Balusters (banisters) are the vertical supports for a handrail on a staircase or landing. In residential properties, balusters are usually wooden, but they can be made of iron, steel, stone, concrete, or other suitable materials. The total construction of balusters and bannister rail is called a balustrade.

Balusters may be have a square cross-section, but they are frequently turned on a lathe to give a wide variety of shapes and patterns. Metal balusters may also be simple round railings or be formed into ornate shapes, depending upon the ingenuity of the designer.

Balustrades are frequently used on the edge of stairways and landings, to provide safety and support. Consequently the balusters must be firmly mounted and able to take the weight of people leaning on them, so a survey report should draw attention to any weaknesses.

Barge board
A barge board is a sloping board along the gable end of a roof that covers the ends of the roof timbers.

Battens (roofing)
Battens are thin strips of wood (or other material) fixed at right angles to the rafters or trusses of a sloping roof, to provide fixing points and support for the tiles or slates.

Battens may also be fixed to felt roofs to cover joins in the felt and to prevent wind-action lifting the felt.

Modern roof tiles have projecting nibs or ridges on their underside which hold the tiles in place when laid so that the nibs rest on the roofing battens. Slates and some types of tiles without nibs have to be nailed to the battens to keep them in place.

Wooden battens are subject to decay and damage caused by water, woodworm and rot. If this happens the tiles or slates will come loose, damaging the integrity of the roof. Loose tiles and slates can also be dangerous if they fall onto passers-by or neighbouring property.

In modern homes battens are fixed over roofing felt (see bituminous felt) and so cannot easily be inspected. A survey report will note if tiles are loose, which may be evidence that the battens need renewing.

In new homes, or when a home is being re-roofed, battens should comply and be fixed in accordance with BS5534.

Bituminous Felt
Bituminous felt is waterproof sheeting used for surfacing roofs or as an underlay beneath tiles or slates.

Bituminous or Bitumen Felt is made from bitumen, a tar-like substance derived during distillation of crude oil, mixed with sand or crushed limestone, and applied to a fibrous membrane made from such materials as hessian, fibre-glass, polyester or paper. The felt may be finished with a coating of sand or fine gravel to give a decorative finish.

Bituminous felt is a cost-effective and convenient way of providing waterproof covering to roofs. It is widely used on flat roofs, as well as on sheds and similar garden buildings.

When used for surfacing flat roofs, the strips of felt have to be joined and finished in such a way that water cannot penetrate. This may be done with a gas torch (products suitable for this purpose are known as 'torch-on'), or using an adhesive applied cold.

Bituminous felt on a flat roof should have a long life if properly applied, but is prone to damage and does decay over time. A survey report should therefore comment on the condition of any flat roof, especially if there is evidence of water penetration.

Bressummer
In timber-framed buildings, a bressummer is a heavy beam supporting the upper floor(s) of a jettied building, i.e. one where the upper floors overhang the ground floor.

Such beams are often carved and decorated (to demonstrate the wealth of the original owner.)

A bressummer can also be the massive timber beam above a fireplace, which supports the brickwork of the chimney, as found in many period properties.

Brick
Bricks used in the UK for house-building have traditionally been manufactured from clay and fired in kilns. Clay bricks are still common, but concrete and other materials are also now used.

Usage in house construction
Although the Romans used bricks in England, their manufacture died out after the Romans left and they were not re-introduced until the Tudor period. Initially bricks were only used in areas where suitable clay was found locally, and the colour of bricks varied depending on the colour of the local clay. As railways grew during the nineteenth century transport became cheaper and the use of bricks became widespread across the country, with red-brick becoming almost universal.

Bricks are now widely used for the construction of residential property, although often only the exterior leaf of a cavity wall is made of brickwork, with lightweight concrete blocks being used for the internal leaf. Brickwork is also often used for non-structural exterior walls of steel-framed buildings, such as blocks of flats, where it provides a more aesthetically-pleasing finish.

The advantage of bricks for building construction is that they are easy to handle and comparatively lightweight, but can be used to construct strong load-bearing walls to a considerable height. It is also fairly simple to construct openings for doors and windows.

In the past bricks were laid on a bed of lime mortar, but cement mortar is now used which provides a better bond to hold brickwork together.

Bricks are porous, and damp can penetrate solid brick walls. Various surface finishes were often applied to prevent this. At one time it was common with more expensive homes for a thin layer of plaster or cement to be applied to external walls, which was then scored with thin lines to mimic stonework. Pebble-dashing was also popular at one time, as were weather-boarding and tile-hanging, which could be applied over cheap bricks to provide a water-resistant finish. However as cavity walls have become universal it has become usual for exterior brickwork to be left without any additional finish.

Bricks are now available in a very wide variety of colours and surface finishes. In addition to the standard size rectangular brick many special sizes, shapes and types are also available from manufacturers. The majority of house bricks are now made industrially, but a few works still produce handmade bricks and can produce non-standard sizes or shapes to order.

Reclaimed bricks can be obtained; when old brick buildings are demolished suitable bricks can be salvaged and may be used to repair or extend period properties, or to construct a new property to blend in with existing homes.

Brick Maintenance

Brickwork rarely requires any attention. Sometimes damage is caused by spalling which occurs when water penetrates bricks and then freezes, causing flakes to break off. A survey will report if there is any evidence of this, and whether remedial work is required. Replacing individual bricks is not a major problem, but if many require replacing an estimate of the cost should be obtained before continuing with a purchase.

Re-pointing of the mortar may also be recommended if the existing mortar has become worn or decayed. If the surface finish of a brick wall has been damaged or become detached from the wall, water can penetrate and cause damage - a survey report will mention any visible signs of this, and further investigation may then be needed.

Occasionally bricks can decay - this is most likely to occur with old bricks which were not adequately fired during manufacture, especially if they have been allowed to become permanently damp. Repair can be expensive, but this problem should be picked up in a survey.

Building conservation
Building conservation refers to historic buildings or heritage assets, including conservation areas which are protected by law. Monuments and buildings of sufficient architectural or historic interest are listed by the Government and graded I, II and III according to their significance in England and Wales. As with buildings located in conservation areas, listed buildings need specific consent for certain works to be carried out on them; for example, replacing roof slates or stone cleaning.

Building Regulations
Building Regulations are statutory regulations made under Section 1 of the Building Act 1984. The Building Regulations 2010 contain the latest major issue of the Regulations, but further amendments and additions have been made since.

The Regulations cover the design and construction of buildings and the services, fittings and equipment provided in or in connection with buildings. These purposes include:

• securing the health, safety, welfare and convenience of persons in and about buildings
• furthering the conservation of fuel and power
• preventing waste, undue consumption, misuse or contamination of water
• furthering the protection or enhancement of the environment
• facilitating sustainable development.

Building works must generally comply with the Regulations, whether involving the construction of a new building or alterations or additions to an existing property. Building works include alterations or additions to gas, electricity, water and drainage services. Alteration of the material use of a property, or certain rooms within a property, may also have to comply with the Regulations.

With all building work, the owner of the property (or land) in question is ultimately responsible for complying with the relevant building regulations. Homeowners cannot rely on contractors or tradesmen to obtain any necessary approvals under the Regulations (but contractors may now be registered under one of several schemes. allowing them to self-certify works.)

Approval of works; completion certificates

For some works it is necessary to give notification directly to the local authority or to an approved inspector for approval of the plans before commencing work. However for many works it is only necessary to deposit plans, and contractors who are members of a recognised self-certification scheme can carry out appropriate works without needing any consent.

Inspection of works was formerly only carried out by local authorities, but independent approved inspectors can now also carry out inspections. In the case of new-build houses and property conversions inspections are often carried out by the NHBC.

When works have been completed and inspected, a completion certificate should be issued. If inspection was carried out by NHBC, this will be incorporated in their own certificate. Registered contractors can issue certificates for work done under the relevant self-certification scheme. It is important to retain any such certificate as if the property is sold the buyer's Conveyancing Solicitor will require to see it as evidence that works complied with the Regulations.

Local councils have wide enforcement powers, and in extreme cases may require the removal of works. Because of the implications of this on purchasers, Conveyancing Solicitors are always concerned to obtain evidence that any building works carried out by a seller or other previous owners comply with Regulations.

In some cases this will entail the seller applying for retrospective approval - often a difficult process when works have been covered over. Also the inspector will apply the current Regulations, which may not have been applicable when the work was done.

Buildmark cover
Buildmark cover is a warranty and insurance protection provided by the NHBC to the purchasers of new-build properties or converted homes. Cover starts when contracts on the property are exchanged. This cover will last to a maximum period of 10 years after the date the property purchase was legally completed.

Calcium Chloride
Calcium Chloride (CaCl2) is an inorganic salt. It is widely used in the building industry as an additive when mixing concrete, where it accelerates the setting time and improves cure strength, especially during cold weather. It also improves the workability of the wet concrete mix.

It has many other uses, such as for melting snow and ice and as a moisture absorber.

If concrete containing Calcium Chloride is directly in contact with steel reinforcing bars or RSJs corrosion may occur. For this reason structural steelwork should be treated with a resistant coating.

Cavity Wall
Cavity walls consist of two separate parallel walls or 'leaves' with a 50-90 mm gap left between them. They are used for the external walls of buildings.

The purpose of the gap is twofold:

• It helps prevent moisture from penetrating through to the interior of the building
• It helps provide heat insulation

The two leaves of a cavity wall are held together by ties which are inserted as the building is being erected. Ties were traditionally made of wrought iron or mild steel, and were sometimes unprotected or possibly coated in bitumen galvanised. Plastic or stainless steel ties are now used.

Some houses were built with Cavity walls in the late nineteenth century, but their use did not become common until the 1920's and they have now become almost universal. It can be difficult to tell from visual in section whether an older property has cavity walls. If this is an issue then it may be necessary to drill a small hole into a wall to check.

The exterior leaf is often constructed of facing bricks, but may be constructed of common bricks or Aggregate blocks which are covered by cement render or other decorative finish (e.g. Pebble Dashing, weatherboarding)

In earlier times the interior leaf was constructed of common bricks, but aggregate blocks of various types have often been used. Nowadays the inner leaves of cavity walls are usually constructed of lightweight aerated concrete blocks which provide better insulation.

Older properties may have had cavity wall insulation inserted in the gap.

Potential problems with cavity walls

• Cavity wall tie failure due to corrosion or rusting
• Damp bridging the gap between the leaves and affecting the interior of the home - damp should not normally be able to cross the gap and penetrate the interior wall. However if the gap is bridged (e.g. by mortar being allowed to fall on the wall ties during building work, or faulty installation) then damp can cross and cause damp patches on the internal walls of the property

Your surveyor will report any suspected problems such as cracks in exterior walls or evidence of dampness on internal walls. Further investigation will be necessary to ascertain the cause. Further specialist surveys will then be required, together with an estimate of any necessary remedial works.

Cavity Wall Insulation
Cavity wall insulation is insulation material inserted into the cavity between the two leaves of a cavity wall.

In modern homes rigid foam boards or semi-rigid mineral-wool or glass fibre "batts" are inserted during construction.

In older homes where the cavity was originally left unfilled insulation can be injected or blown into the cavity. Materials used for this purpose are loose mineral- or glass-fibres, urea formaldehyde foam and bonded polystyrene beads. The insulation material is injected through small holes drilled into the mortar between courses of the outer brickwork - these holes are then filled in, leaving little external evidence of the insulation.

When Cavity wall insulation has been inserted into an existing home the installer should be registered with the Cavity Insulation Guarantee Agency (CIGA) and issue a 25-year guarantee. This should be handed over to the buyer when a home is sold.

Concerns have been raised that Cavity wall insulation can cause a variety of problems if it is not properly installed. These include:

• Dampness caused by moisture penetrating the exterior wall and being transmitted across the cavity to the interior walls of a property. The purpose of the cavity in a cavity wall is to stop moisture penetration. Properly installed insulation should not transmit water across the cavity, but this may occur if installation has not been carried out in accordance with manufacturers' specifications.
• Mould and damp occurring within the cavity. This may occur if voids are left in the insulation material - water vapour in the void can then condense causing dampness and encouraging the growth of mould
• Wall-tie corrosion and failure - wall ties are an essential feature of a cavity wall, to tie the two leaves of the wall together. These ties should be resistant to corrosion, but if insulation material gets wet so that the ties are in constant contact with water they may corrode and fail. This problem has also been linked to the use of urea formaldehyde foam insulation.
• Polystyrene beads are not properly bonded - if alterations are then carried out involving cutting into a wall (e.g. when inserting a new window) the beads flow out from the cavity.

An ordinary survey should highlight any obvious problems with damp, but a proper survey may be required to ascertain the cause of problems with cavity wall insulation. This would involve drilling holes in the exterior walls and inserting a probe with a cctv camera.

If a seller does not know whether a property has Cavity wall insulation and there is no external physical evidence then a cctv probe would also be necessary.

Cavity Wall Tie Failure
The ties used to bind the two leaves of a Cavity Wall were often made of mild steel or wrought iron. Such ties were protected from corrosion by being galvanised or in earlier times by a coat of bituminous paint.

Over the course of time the galvanising or other protection can wear away. If this happens the ties will rust due to the presence of air and water in the cavity. When steel corrodes it expands in thickness, so the ends of the wall ties embedded in the outer leaf will lift the bricks above. This causes horizontal crack to appear in the brickwork. In extreme cases, the outer leaf can become separated from the inner leaf and fall off, although this very rarely leads to any further collapse of the wall.

If your surveyor suspects wall tie failure, he will recommend further investigation. This is done by locating the ties using a metal detector and then either removing a brick or the mortar or drilling a small hole and inserting an endoscope (a TV camera on a flexible probe) into the cavity to examine their condition.

If a substantial proportion of the wall ties have become corroded it will be necessary for them to be replaced; this can be an expensive operation.

Since 1981 building regulations require a higher standard of protection, and builders now use plastic or stainless steel ties, so failure of the wall ties is much less likely to occur in recently built homes.

Ceiling Joist
Ceiling joists are beams laid across the top of the walls of a building. They have two main functions:

1. To tie the walls together and prevent them spreading apart under the load of the roof.

2. To provide a support for the ceilings.

In most residential properties these joists are lengths of solid timber, either fixed to wall plates laid along the top of the brickwork, or secured to joist hangers which are fixed to the walls.

When a building has a sloping roof the joists are also fixed to the rafters, which stops them spreading under the weight of the roof tiles. On flat-roofed buildings the roof boards and waterproofing material are fixed directly on top of the ceiling joists.

Builders now often use pre-fabricated roof trusses. Such trusses are comprised of two rafters and a joist, firmly fixed to form a strong triangular structure. (Additional supports are also inserted to stop the rafters sagging.)

In modern homes ceilings are usually constructed of plasterboard nailed to the joists and finished with a skim coat of plaster. In older buildings the traditional lath and plaster construction may be encountered where the plasterwork is supported on wooden laths nailed crosswise to the ceiling joists.

In recently-built homes the joists will comply with building regulations, but in older properties considerable variations in size and spacing can be found. Under-sized joists can cause problems if they are insufficient to carry any load upon them, or if they are spaced too far apart. Problems may also occur when a loft extension has been added or other alterations have been carried out and the joists have been cut into.

As with any other building timbers, ceiling joists may be subject to decay or damage from woodworm and rot. Problems with damp decay may also occur if loft insulation has been installed without proper care being taken to prevent condensation in the loft space.

A building survey will indicate any apparent problems with the ceiling joists, and may recommend that further specialist surveys are carried out.

Cement Weathering
Cement weathering is a narrow band of cement that is applied to the base of a chimney stack where it meets the roof to prevent water seeping through the join. This protection works in a similar way to chimney flashing and is more commonly found on older buildings.

Condensation
Condensation is the water that forms on cool surfaces when warm air comes into contact with it. It usually forms on the inside of windows, particularly in bathrooms and kitchens, where cooking, bathing and clothes drying takes place. Adequate ventilation is needed to get rid of condensation.

Conservation Area
Conservation areas are areas designated under the Planning (Listed Buildings and Conservation Areas) Act 1990 for their special architectural and historic interest. In such areas special planning regulations apply to all properties, whatever their age or architectural merit.

There are more than 10,000 Conservation areas throughout England and Wales. Many include residential properties in areas such as:

• the centres of historic towns and cities
• fishing and mining villages
• 18th and 19th-century suburbs
• model housing estates

Conservation areas are designated by local authorities, often after discussion with bodies such as English Heritage (or Cadw in Wales) as well as local organisations.

The demolition or substantial demolition of a building within a conservation area will in most cases require special Conservation area consent. Permission may also be needed from the local authority for alterations such as:

• inserting or replacing windows
• installing satellite dishes and solar panels
• adding conservatories or other extensions
• fixing cladding to the exterior
• laying paving or building walls

Councils can make Article 4 Directions to cover conservation areas - works which are usually permitted development not requiring planning consent will require specific consent in such areas.

Conservation areas are not intended to remain frozen in time, change is often necessary to accommodate the demands of modern living. However the purpose of the legislation is to ensure that alterations and further development are done in a way which preserves or enhances the existing character or appearance of the area.

When buying a property, the local search made by the Conveyancing Solicitor will show if it is located in a conservation area.

The buyer's surveyor should be alerted so as to check whether any works have been carried out for which consent might have been needed.

If works are carried out without appropriate consent the local authority has powers to require property owners to restore the property to its original condition.

Buyers therefore need to ensure that necessary consents have been obtained for works done be the seller.

If an owner or buyer is planning works to an affected property, they should contact the local council's planning department for further advice. English Heritage/Cadw also offer general help and advice.

Anyone intending to prune or cut down a tree in a conservation area must notify the Council 6 weeks in advance.

The Council will then assess the contribution the tree makes to the character of the conservation area and decide whether to make a Tree Preservation Order.

Corrugated Iron Roofing
Sheets of corrugated iron were first used as roofing in the early 19th century. While this type of roofing is now made of galvanised steel, the original name of corrugated iron remains. Corrugated iron roofing is robust and long-lasting.

Cross-Bracing
Cross-bracing is the addition of diagonal reinforcement applied to any form of framework.

Strips of wood, metal or other material may be used, which are crossed to form an X shape and help stiffen a frame by preventing any lateral movement.

In residential properties with timber floor joists, cross bracing can be inserted between the joists to prevent them from moving, eliminating squeaking and deflection, and increasing overall stability in the floor system.

Cross-bracing can also be added to ceiling joists, especially in larger properties.

Cross braces in such applications is typically constructed from wood strips, although metal cross bracing ties are sometimes used, as well. Bracing strips are nailed from the top of one floor joist to the bottom of the next joist, and vice versa, forming an X.

Cross braces may be installed during the construction process or added to older homes.

Cross-bracing may also be inserted in the roof structure to keep roof trusses in alignment.

In timber and steel-framed buildings cross-bracing is used to hold the frames square.

Damp-Proof Course (DPC)
Water can rise up through most materials used for building houses, such as brick, concrete and stone. (In scientific terms, this is caused by capillary action.)

To prevent this happening, a damp proof course (DPC) is inserted in any walls which rest on foundations laid in the ground. This is intended to provide an impervious barrier to water. The DPC is installed as a horizontal layer between two courses of brickwork. It should be a short distance above ground level so that ground water cannot bridge the DPC.

In modern properties the DPC is usually a thick plastic strip, but other materials which have been used include Bituminous Felt, slate, and lead sheet. The Romans used oyster shells for this purpose.

Cavity Walls require a DPC in each leaf of the wall.

Potential problems with DPCs:

• Failure of the DPC - this might be caused by damage during installation, or cracking of rigid DPC materials, such as slate, caused by settlement or subsidence.
• Bridging of the DPC - this often happens when earth or rubble is heaped up against an outside wall, or a patio or paved area is built up above the level of the DPC. It can also occur when external rendering is applied across the DPC. When this happens moisture can rise into the brickwork above the DPC.

The surveyor will report on any indications of problems with the DPC, and advise whether a further specialist survey is required or if remedial work is necessary.

Damp-Proof Membrane (DPM)
A damp-proof membrane (DPM) is a wide impervious sheet used to inhibit moisture within a building. In timber structures, a DPM will protect the timber against damp, rot and mould. It is usually placed underneath a floor to prevent rising damp or in a sloping roof.

Daylighting
Daylighting is a way of controlling or expanding the light in a building through the use of skylights and windows.

Death Watch Beetle
A medium-sized wood-boring beetle (scientific name Xestobium rufovillosum), Death Watch beetle is a notorious pest as larvae can cause major damage to wood beams and floors in buildings and to wooden furniture.

The death watch beetle is common and widespread in southern England, but less common in the North.

The adult females lay eggs in crevices or holes in dead wood, especially the hardwoods such as oak or elm often used as structural timbers in traditional buildings. The eggs hatch into larvae, which then tunnel into the wood. it is these larvae that do most of the structural damage to the wood.

The presence of the larvae in wood can go unnoticed until the adults emerge, leaving distinctive holes at the surface. These exit holes measure around three to four millimetres in diameter, considerably larger than those left by the common furniture beetle (Anobium punctatum).

During their mating season the beetles bang their heads against the wood, creating a distinctive tapping or ticking sound. It is likely that the 'Death Watch' name derives from people hearing this sound during the quiet of the night while they were keeping watch over a dying or dead person in an old house or church. A superstition grew that anyone hearing the sound would soon die.

Death Watch beetle prefers damp conditions especially when there has been some kind of fungal decay such as wet rot in the timbers.

A building survey will indicate if there is visible evidence of Death Watch Beetle, such as flight holes and tunnels. As damage is most likely to be found in period properties a specialist survey is recommended for purchasers of such properties unless there is evidence that previous attacks have been eradicated and remedial treatment carried out.

The larvae tend to tunnel towards the centre of the timber resulting in damage that may be more extensive than is apparent from the exterior. The structural integrity of the timber should always be checked if there is evidence of an attack. New diagnostic techniques, using a combination of ultrasound and micro-drilling, allow very precise location of cavities and tunnels within the cross-section of the timber.

It can be difficult to determine whether a beetle attack is active or dead, and whether treatment is necessary. Death Watch Beetle attacks found in historic buildings may have died out many years - even centuries - ago, but the distinctive flight holes will still be evident.

The presence of fresh, brightly coloured bore dust and clean dust-free flight holes certainly indicates that the attack is active, but their absence may not necessarily mean that the attack is dead. The larvae can remain inactive but viable for many years if conditions are unfavourable, only to re-emerge later.

Treatment may include:

• Chemical treatment to kill off beetles and larvae
• Removing and replacing badly decayed timber
• Taking steps to ensure timbers do not remain in contact with any source of damp, e.g. where existing roof timbers are laid directly on solid stone or brick walls

Defect
Defects are issues or problems identified by a chartered surveyor during a building survey. These can including condensations, gutter or roof leaks, missing roof tiles, lack of ventilation and poor décor or finishes within a property. Defects will be listed on the survey.

Design Life
Design life is often referred to in the contract of sale of a property and deals with what was once known as the life span of the building. The design life will vary depending on the structure, maintenance and environment.

Dilapidation Report
Dilapidation refers to decay or damage in a building, often caused by lack of maintenance and repair. A dilapidation report is often commissioned on commercial or rented property when a lease or tenancy ends.

Dilapidations Survey
A dilapidations survey is an assessment of the condition of a commercial property carried out by an independent surveyor on behalf of a landlord or property manager. The survey details what work is required to return the property to its original condition.

Dormer
A dormer is a part of a building projecting from the sloping roof, typically housing a dormer window.

Dormers are usually constructed to provide light and additional headroom for rooms constructed in the attic or loft of a house, and are often constructed in connection with an attic or loft conversion.

Dormers may be roofed in a variety of ways, including:

• Gable end dormer with tiled sloping roof to match the roof on the rest of the building
• Flat roofed dormer - if the flat roof slopes this may be called a 'shed dormer'
• Eyebrow or eyelid dormer - the main roof is carried over the dormer window in a gentle curve, giving the appearance of an eyebrow

Dormers can suffer from problems if they have not been properly constructed, or if the original roof trusses have been weakened when a dormer has been inserted into an existing roof. Problems can also arise with ingress of rainwater at the junction of the dormer walls and the sloping roof. A survey report should indicate the existence of problems if there is visual evidence of them.

Double Glazing
Double glazing refers to sealed window units that contain two separate panes of glass. The gap between the panes provides insulation against the cold and also against noise. Double-glazed windows also reduce the amount of condensation.

Downpipe
A downpipe is any pipe for carrying waste water or rainwater and fixed to a building.

Downpipes were traditionally constructed of cast iron or lead, but more recently plastic, steel and aluminium have become widely used. Downpipes may be circular or square in cross-section.

Downpipes carrying rainwater from roofs are usually fixed to the exterior walls of a building. Those carrying waste water and sewage are now fitted inside buildings, but in older homes they are attached to the exterior.

On older properties downpipes generally discharged water into a drain or gully by means of a 'shoe' fitted at the base of the pipe to change the direction of the flow of water, discharging it clear of the wall. In newer homes the downpipe is taken down into the ground to a direct connection with the sewer pipe, avoiding having open drains around a building.

On period properties downpipes are often topped by funnel-shaped hoppers, which collect water from one or more smaller downpipes. Elaborately-shaped cast iron and lead hoppers are of great significance on the facades of many historical buildings.

Problem areas:

• Broken pipe - this is most likely to occur in cast iron pipes which are quite brittle, and susceptible to damage if hit. Breakages can also occur when water in a pipe freezes.
• Corrosion - cast iron pipes require regular re-painting - if this has not been carried out then rust will build up
• Loose fixing brackets - if brackets become loose, pipes may buckle, come apart at pipe joints or fall of the wall.
• Blocked pipes and hoppers

Water flowing from a cracked or broken downpipe is likely to cause damage to adjacent walls as well as causing damp problems, especially in houses with solid walls. If a pipe carries waste water or sewage then a leaking pipe will be a health risk. Broken pipes should therefore be repaired as soon as possible.

Downpipes carrying rainwater from gutters are prone to blockage from leaves and other debris. If this occurs rainwater is likely to overflow, particularly during a storm, and run down the walls of a building, giving rise to high levels of damp.

A survey report will highlight any problems and recommend any necessary remedial work.

If downpipes and hoppers on a period property need replacing it is likely that the local authority will require replacement pipes to match the original ones, especially if the property is a listed building or in a conservation area. There are a number of manufacturers who provide period-style fittings, but the cost is considerably higher than for modern plastic pipes.

Dry Rot
Dry rot in timber is caused by a wood-destroying fungus with the scientific name Serpula lacrymans. Over a period of time, woodwork affected by dry rot will be totally destroyed, so any occurrence of dry rot is potentially dangerous. This is particularly true if the rot occurs in structural building timbers such as roof trusses, joists or beams.

Although the fungus only attacks wood, it can spread through or across masonry, especially when damp. An outbreak in one part of a building can spread to timber throughout the building, making dry rot one of the most damaging forms of rot in buildings. In severe, long-untreated cases, expensive works may be required to eradicate the fungus and to replace decayed timber.

Despite its name, dry rot only occurs when timber is damp. The fungus thrives in dark moist conditions, in parts of the property hidden from view or easy access, and therefore often spreads extensively before the damage is first noticed.

It is more likely to occur in older homes, as timber in modern properties is now treated against rot.

These are some of the typical signs of dry rot:

• Wood shrinks, darkens and cracks in a characteristic rectangular block pattern.
• In humid conditions white, fluffy 'cotton wool' appears and 'teardrops' may develop on the growth.
• In less humid conditions a silky grey to mushroom coloured skin often develops which can be peeled off.
• Active decay produces a musty, damp odour.

A building survey will indicate if there is any evidence of dry rot, and further investigation may be required. As dry rot tends to develop in parts of buildings which are not easily accessible, inspection can be difficult.

Treatment will usually be a twofold process. It will first be necessary to investigate the cause of the dampness which has enabled the fungus to grow, and remedy that. If damp has been caused by condensation within the building e.g. from a bathroom or kitchen, the provision of adequate ventilation may remedy the problem. However if rot has occurred because structural timbers have been in contact with damp masonry, it will either be necessary to prevent damp penetrating the wall or if that cannot easily be done (e.g. in old buildings with solid brick walls) then provision will have to be made so that timbers are not in direct contact with the masonry and new treated timber may have to be inserted.

Secondly it will be necessary to determine whether affected woodwork can be treated to eradicate the fungus, which will depend upon how far it has decayed. Provided that the structural integrity has not been affected, it may only be necessary to apply one of the various proprietary treatments which are now available. Otherwise it may be necessary to replace affected timber.

Durability
A building's durability will be assessed by a chartered surveyor during a structural survey. This survey examines the strength and stability of a building and is most often used for older properties.

Eaves
An eave is the edge of a roof. Eaves usually extend beyond the exterior walls of a building, and are intended to throw rainwater from the roof clear of the walls, to stop water getting in between the junction of the roof and the wall.

Before Guttering came into general use eaves often extended well beyond the walls of buildings so that rainwater was thrown well clear of the walls. This would prevent water damaging the wall and washing away the footings of the building.

Building constructed or surfaced with porous materials, such as plaster or cob, usually have eaves projecting well beyond the walls to prevent rainwater damage. This is particularly common with thatched roofs which cannot have guttering.

The overhang of eaves beyond a building's wall is known as the 'eavesdrop' and when this projects beyond the legal boundary of a property an easement of eavesdrop is required.

A building survey will indicate if there are any particular problems with the eaves, the most likely being decay or rot to external timber associated with the eaves, such as Fascia boards and Bargeboards.

Economic Life
The economic life of a building or property is the amount of time the building can be in use before it makes more financial sense to replace it.

Engineer's Report
An engineer's report is prepared by a structural engineer after an assessment of the load-bearing structure of a building, including its foundations, walls and roofs.

Extension
An extension is an addition to an existing property, which may be to the side, rear or top of a building and may be single or double storey. Some property extensions may turn the garage into accommodation.

It's important that planning permission is granted and building control regulations met when building an extension or buying a home with one.

Eyebrow Window
A type of dormer window inserted in the roof of a house. An Eyebrow Window has no vertical sides, instead the top of the window frame is gently curved. The roof-tiling then follows the line of the curve, so that the roof appears to have been lifted over the window. This gives such windows their characteristic and attractive eyebrow shape.

Fascia
In modern use, the fascia (or fascia board) of a building is the horizontal board fixed to the edge of the roof's rafters where these form the eaves of a building, or with flat-roofed buildings, boards fixed to the junction of the roof and the walls.

Fascia boards may be either made of wood or uPVC, the latter now being popular as it is maintenance-free and does not require painting.

On buildings with sloped roofs, the fascia board stops water penetration into the end-grain of timber rafters. Brackets to support guttering are fixed to the fascia.

Fascia boards on flat-roofed buildings may be necessary to anchor the roofing material, and stop wind and rain penetrating between the roof and the walls. It may also be fixed for decorative reasons.

A survey report will show any visible problems to fascias, such as damage or decay particularly to timber fascia boards, which may require attention.

Feasability Study
Where an extension is planned or a property development project in the pipeline, a feasibility study will be carried out to assess if the outcome will be financially successful. The study will examine the site's suitability, planning approval and budgets.

Flashing
Flashing describes strips of sheet metal or other impervious material used to prevent rainwater penetrating into joints between different parts of a building.

The most common situations where flashing is used are:

• In the valleys where different sections of a roof meet
• Where the roof of part of a building abuts a wall, e.g. where a single storey extension has been built against the rear wall of a two-storey house.
• Where a chimney stack or pipe passes through a roof
• Around window frames and sills
• Around roof lights

Flashing may be visible or concealed, or a combination of the two, depending on the type of joint. Sheet metal is widely used, especially where flashing is to be visible. Lead and copper were widely used for this purpose in the past, and more recently zinc alloy, aluminium, galvanized steel and stainless steel have been used. Modern synthetic materials are also now available and widely used in areas where the flashing will not be visible.

Whatever material is used should have a long life, as it can be difficult and expensive to replace flashing.

It can be difficult to spot if flashing fails, but if this does happen water can penetrate into timber and brickwork in inaccessible areas, causing extensive damage.

Flashing should direct water away from the structure of a building, and should be designed so that rain cannot be blown in by the wind. It is also important to ensure that water cannot penetrate between joints in the flashing material, e.g. by capillary action. Installing or replacing flashing is therefore a job best left to experts.

Flat Roof
A flat is one that is almost level in contrast to a pitched or sloping roof. It does have a gradient that allows rainwater to run off. Flat roofs tend to have a shorter life span than sloping roofs.

Flaunching
Flaunching is the name given to the bed of mortar which holds chimney pots in place on top of the chimney stack. Flaunching also helps prevent rainwater permeating the top of the brick or stone of the stack.

In older homes, lime mortar was used for flaunching, and this will deteriorate over the years. Even when cement mortar has been used this may have cracked, allowing water to penetrate and weaken the bonding of the chimney pot.

It is therefore important to check the condition of flaunching. If it is unsound the chimney pots may be insecure and in extreme cases could topple in high winds resulting in damage to property or injuries to passers-by.

The condition of the flaunching usually can't be readily seen from ground level and a Surveyor will often recommend that it is checked when repairs are being carried out to roofs and gutters. However it is easily possible to tell if a building was constructed with lime mortar rather than modern cement mortar, in which case it is more than likely that the chimney stacks will need detailed inspection.

Minor cracks in cement mortar may be repaired by filling with mastic, but if more extensive repair is required this is likely to entail erection of scaffolding to give safe access.

Floor Joists
Floor joists support a floor in the upper storeys of a building. These timber frames are placed equidistant and parallel to each other between load-bearing walls and are covered above and below by ceiling plaster and floor coverings, respectively.

Floors (solid and suspended flooring)
Floors in commercial and residential property is usually either suspended or solid.

A suspended floor is a specialist construction that consists of solid concrete, sleeper walls and timber joints that support a timber floor. The likes of electrical wires can be run under the floor boards.

A solid floor consists of solid concrete built into the ground, which can bear more weight than a suspended floor.

Foul Drain
Foul drains carry used water and solid waste from toilets, sinks, baths, showers and other sanitary fittings as well as washing machines and dishwashers.

Above-ground pipework is referred to as sanitary pipework; the underground pipework is referred to as foul drains and foul sewers. (Generally speaking, a drain serves a single property while a sewer serves several properties.)

Plastic drain-pipes are now used, and are much less susceptible to cracking and breakage than the earthenware pipes which had been used previously. Earthenware pipes can have a very long life, but subsoil movement or tree roots can lead to fractures or pipe joints failing. Any such breakage or leaks in foul drains will have serious consequences when sewage leaks into the surrounding area.

Drains are also liable to blockages - this is particularly liable to occur when solid matter collects at bends or joints in the pipe run - which will require removing. If blockages occur frequently this may be due to a design fault in the system, requiring a new installation.

A full building survey will include lifting an inspection cover if possible so as to see if waste water is running through the drainage system satisfactorily. If a problem is suspected then it may be necessary to employ a contractor to insert a CCTV probe through the pipe to locate the broken pipe or blockage.

Building over an existing drain or sewer can damage pipes, as well as making it more difficult, time consuming and expensive to clear blockages and repair or replace faulty drains. Homeowners should therefore check the position of foul drains before starting any extension or other work which might interfere with them. Determining the location of foul drains usually requires a survey, as maps are rarely available, but it is always best to contact the local authority and water company for advice.

Until recently homeowners could be liable to contribute to repair costs for lengthy runs of shared or combined drains serving several properties. However since 1 July 2011 all sewers and lateral drains are publicly maintained if they connect to the public sewerage system and serve more than one property. Homeowners do remain responsible for any foul drains solely serving their own property.

Foundation
The foundation is the lowest part of a building's structure that is built into the ground. Most houses will have shallow foundations while taller buildings, such as a block of flats, will have deep foundations.

Gable End Wall
A gable end wall is the triangular section of wall supporting two sides of a sloping roof. The phrase may also be used to describe the whole of the end wall of a building which includes a gable.

On most modern houses the roof tiles or slates extend over the top of a gable end wall, with some form of weatherproofing added between tile and brickwork to stop the ingress of rainwater. Bargeboards are often fixed to the horizontal timbers or Purlins of the roof when these rest on the top of the wall.

Gable end walls may also rise above the roof line, in which case Flashing must be inserted to seal the junction of the roof tiles or slates and the inner surface of the wall. Gable end walls rising above the roof line may be finished in a slope following the slope of the roof, or as stepped, corbel or Dutch gables. The wall should be capped or finished in such a way that rainwater runs off and cannot penetrate the wall.

Potential Gable End Wall problems

Because gable end walls rise above the level of the main walls of a building, they are susceptible to damage from high winds. This should not be a problem when they are properly braced, but if suffering from a lack of lateral restraint the following damage can arise:

• Outward bowing of the walls
• High level horizontal cracking
• In extreme cases, collapse of the wall
• Failure of the flashing or other means of waterproofing of the junction between the roof and the wall

On properties where the gable end wall rises above the roof line, the top of the wall should be finished in such a way that rainwater cannot permeate the wall. If this finish decays or cracks then water and frost action can severely damage the wall.

A survey will show any apparent defects caused by any of these problems, and suggest possible remedial action. If the surveyor considers that any gable end wall is not properly braced then bracing can be inserted in the roof space. However if a wall has already suffered damage it may be necessary to rebuild the wall as well as installing bracing.

Garret
A habitable attic or small living space at the top of a house; often fitted within the roof space, and having sloping ceilings.

Before the days of lifts, this was the least attractive part of a building. Servants rooms would usually be in this part of the building, and if such rooms were let out privately they would not attract high rents.

For these reasons a garret was traditionally regarded as the least prestigious position in a building, and synonymous with a cramped living space occupied by servants or the poorest classes.

The word is derived from a Middle English (via Old French) word used to describe somewhere where soldiers kept watch or were quartered, hence its unsavoury connotations.

Garrets were very often built within mansard roofs, and have skylights or dormer windows to provide light and air.

This style was very popular in nineteenth-century France (Act 1 of Puccini's opera La Bohème is set in a Parisian garret occupied by four impoverished students) but examples can be found in England.

Geomatics
Geomatics, also known as geographic information systems, is the science and study of the natural, built, social and economic environments.

A geomatics surveyor or land surveyor measures, maps, assesses, collects and interprets information about land, particularly land that is being redeveloped.

Geomechanics
Geomechanics is the study of the mechanics of soil and rock. Geomatics surveyors use geomechanics to interpret information about land, particularly land that is being redeveloped.

Green Building
Green building refers both to a style of building and to a type of building.

The style of green building focuses on protecting the natural environment around a construction site.

A type of green building is one that focuses on sustainability and reduced carbon footprint.

Ground Heave
Ground heave occurs when the ground beneath a building moves upwards, i.e. the opposite of subsidence. Heave is caused by the expansion of the ground, and is usually associated with clay soils which swell when they get wet.

Ground heave often occurs when a mature tree near a property is removed or dies. Trees act as powerful pumps, and some species such as willow or oak will take a large amount of ground water out of the sub-soil. Once the tree is removed this water will re-hydrate the sub-soil and cause it to expand. Another possible cause of ground heave is water permeating into the subsoil, such as from a broken drain or culvert carrying a watercourse, or if building works on nearby land interfere with existing ground drainage.

Ground heave can also be caused by frost action, as water expands when it freezes; some types of soil are 'frost susceptible' - this tends to be a feature of silty and sandy clays.

Heave can cause significant damage to building foundations and structure. Signs of damage include cracks in brickwork, windows and doors sticking as their frames become out of square, and lifting of paths and patios surrounding a property. Remedying such damage can be an expensive job, and a home may be uninhabitable while work is being carried out - in extreme cases a property may have to be demolished.

A survey will indicate if there are any signs of heave in a property. It may also advise on potential dangers should existing trees be removed. If it is necessary to remove an existing tree, or one dies, expert advice should be sought straight away. Care should also be taken when planting trees near a house; varieties which can grow large and draw up a large volume of water should not be planted too close to an existing building.

Gulley
Gulley (also spelled 'Gully') A gulley in its widest sense is a channel carrying water.

In residential properties, 'gulley' usually means the open gulley at the foot of a downpipe which collects water (e.g. rainwater or waste water) discharged from the downpipe and channels it into the underground drains.

Gullies are prone to blockage from debris such as leaves falling into them, as well as water-borne debris such as food. If a gulley collects water from a sink then fat in the water will be deposited in the gulley which can build up and cause a blockage.

Gullies usually incorporate a grating to prevent larger debris getting into the drainage system. Such gratings need to be removed and cleaned from time to time.

Any broken gratings should be replaced, as otherwise larger debris getting into the drains could cause a blockage which would be more difficult to remove.

Covers can also be bought which stop leaves and airborne debris falling into a gulley.

Blocked gullies will result in water seeping into the foundations of a building, so they should be inspected and cleaned regularly.

There are a number of different arrangements for making the connection between downpipes and drains.

If the water discharges into a combined drainage system the gulley should incorporate a trap (i.e. a 'U' bend similar to that found in a WC) to prevent smells rising up from the sewers.

This type of gulley is also recommended where the rainwater discharges into a surface water drain. A trapped gulley should always have water in the bottom (in the same way that there is water in the bottom of a toilet bowl.)

If there is no water this might indicate that there is a crack at the base of the gulley, allowing water to drain into the ground near to the foundations where it can cause damage.

Dry gullies should therefore be investigated and replaced if found to be broken.

A building survey will report on any apparent problems with gullies, such as evidence of blockages.

Cleaning gullies out is normally not a difficult task (although rather dirty) but replacing a broken gulley would have to be carried out by a builder.

'Gulley' may also describe the channel at the point where two sloping roofs meet, which channels rainwater from both roofs to the gutters.

This is also known as a valley; see separate entry for more information.

Gutter
A gutter is a trough placed at the bottom edge of a roof to collect rainwater and channel it into drains by means of downpipes.

Gutters should prevent rainwater running of the roof and down the side of a building, causing damage to the walls and foundations.

The majority of domestic buildings now have gutters formed of uPVC or other plastic material, or aluminium.

Older properties may have gutters made from cast iron or galvanised steel.

Such guttering is factory-made, and attached to the building by means of brackets fixed to the fascia board.

Gutters are supplied in a variety of cross-sections. Half-round is very common, but other cross-sections include ogee, square, and other moulded shapes.

On some buildings, especially those which have a parapet rising above eaves level, gutters may be constructed as trough integral with the building.

This is a feature of many period properties. Lead was traditionally used for this purpose, but more recently glass fibre, aluminium and other materials have replaced lead.

Gutters should be fixed so that they slope slightly down towards each downpipe, to ensure that rainwater runs off and does not remain in the gutter when it is not raining.

To function properly gutters should be kept free of obstructions. Common causes of obstruction include dead leaves and other vegetation, birds' nests, dead birds and balls, as well as general debris washed off the roof.

Care should also be taken to stop climbing plants such as ivy or wisteria from growing into the guttering. If dirt builds up in a gutter then grass and other plants frequently take root and should be cleared.

Guttering must be of sufficient size to cope with rainwater runoff. It should also be securely fixed, and not leak.

A building survey will include a visual inspection of the gutters, and comment on any apparent faults, together with any required repairs.

However some defects may only be apparent when it is raining, and cannot therefore be determined by an inspection during dry weather.

Care will have to be taken if gutters on a period building, especially if a Listed building or in a conservation area, need renewing.

It is likely that they will have to be replaced with new gutters to match the style of the original.

Fortunately several manufacturers now offer guttering in a variety of period styles, and in a range of materials, complete with suitable downpipes, hopper heads and other period-style features.

HIP Roof
A Hip Roof (or Hipped Roof) features slopes on all four sides of a building, meaning that there are no gable end walls.

If a building has a square floor plan, then a hip roof will take the form of a pyramid, rising to a central point. If a building has a rectangular floor plan, then a hip roof will rise to a ridge running along the longer axis of the building. Hip roofs are particularly suitable for buildings with irregular floor plans.

As they have no gable ends, hip roofs are considered less prone to damage caused by strong winds. Another advantage is that they do not require any external timber work (such as Bargeboards) above the height of the Eaves, so less maintenance is required.

Hipped roofs are more complicated and expensive to construct than gabled roofs. The roof trusses generally have to be constructed on site, rather than being prefabricated.
Hipped roofs usually slope evenly on all sides (unlike mansard roofs where each segment of the roof has two slopes, one shallow at the top and one steep on the lower part).

HIP Tile
A hip roof is one with sides that slope down to the walls with no gables or vertical sides to the roof.

Hip tiles are fixed by mortar bedding to the roof and are usually the last tiles to be placed on a roof when it is laid.

House Longhorn Beetle
A non-native species to the UK, the house longhorn beetle is one of the main causes of woodworm in buildings.

This creature is most often found in the south-east of the UK.

Inspection Chamber
An inspection chamber is the access point to underground pipework such as drainage systems. The chamber allows maintenance and blockages to be removed.

Inspection chambers are similar to manholes but can only be accessed by cameras and rodding.

Interim Dilapidation
Dilapidations are breaches of a lease by tenant or landlord. Where formal listing of these breaches is made, it is in a Schedule of Dilapidations.

Before that is served, an interim schedule of dilapidations may be served at any time during the term of a lease.

Ivy
Ivy (Hedera helix) is an evergreen climbing plant which is often grown as a decorative cover on house walls and fences. The plant has glossy leaves with three or five pointed lobes, often strongly veined, and grows in any type of soil, tolerating both deep shade and full sun.

Why does Ivy create problems for Home Surveys?

Ivy will grow into a dense mat, with thick woody stems growing in all directions. This dense cover can hide defects in a building, hindering maintenance and making it difficult for a proper survey to be carried out.

The plant supports itself by aerial roots which cling to the masonry of a building. These roots can penetrate cracks or joints, especially in older brick or stonework with lime mortar joints, which can cause structural damage. It can also cause damage if allowed to grow over walls which have been surfaced with stucco, pebble-dash, or other rendering, and it may cause the finish to detach from the wall.

The aerial roots and runners can be particularly damaging if allowed to grow over woodwork, such as Fascias, Bargeboards, or window surrounds, or between woodwork and a wall.

Ivy can grow to a considerable height, so will require regular trimming to ensure that it does not grow into gutters. Shoots and runners must also be prevented from growing into roof spaces and voids or beneath foundations where they will cause damage.

Does Ivy cause dampness?

It has generally been thought that walls covered with ivy will be more prone to damp problems. However, a recent study carried out for English Nature indicated that the ivy can in fact help to weatherproof a wall, as well as providing protection from the effects of pollution.

Ivy can be difficult to remove. As its roots cling to the building pulling it away can cause more damage and will often leave root-tips embedded in mortar or plaster which is unsightly and difficult to remove. The leaves are resistant to weed killers, and any roots remaining in the ground will quickly grow again. Therefore removing any substantial growth of ivy will probably require expensive professional work.

English Heritage now advises against indiscriminate removal, but if ivy is left it will need regular management.

A building survey will indicate if there are any apparent problems from the growth of ivy, and may recommend a further survey or inspection by a specialist.

Japanese Knotweed
A non-native UK species, Japanese knotweed (fallopia japonica) is a weed that spreads rapidly in a garden and needs to be removed by a specialist.

Property sellers must state whether Japanese knotweed is present in their garden or grounds on the TA6 property information form used in conveyancing.

Joint Contract Tribunal
The Joint Contract Tribunal (JCT) provides standard contracts and guidance notes for construction that set out the responsibilities of all parties involved in the building process.

Land Registry
The Land Registry is where the ownership of all land and property in England and Wales is registered.

Anyone buying or selling land or property, or taking out a mortgage or loan on property or land, must apply to the Land Registry to register their interest.

Lath and Plaster
In many older homes constructed before the 1930s, ceilings and internal walls are usually constructed of lath and plaster.

Laths are thin wooden strips which are nailed across the ceiling joists or studs of internal walls. Small gaps are left between the laths. The gaps then form a key to hold and support the plaster as it is applied over the laths - as the plasterer applied the wet plaster he forces into the gaps so that it mushrooms out on the reverse side.

Over time the plasterwork is liable to crack and come loose from the laths. When this happens chunks of plaster can fall off the ceiling.

The laths may also suffer decay from woodworm, dry rot or damp.

Repairing or renewing a lath and plaster ceiling can be an expensive job, and many property owners now prefer to have the old ceiling removed completely and replaced with plasterboard. However period properties often have elaborate plasterwork moulding and cornices and if it is desired to replace these the services of a skilled plasterer will be required. This is especially necessary for listed buildings.

Lead Roofing
Lead has been used in the roofing industry for centuries because of its durability and flexibility. It is generally used as flashing (covering joints) on a roof because it can be moulded into complex shapes.

Lintel
A Lintel is a beam across the top of a door, widow or other opening in the walls of a building, and supporting the structure of the walls above the opening.

A variety of materials can be used for lintels. Stone or wooden beams will be found in older properties, but in modern properties steel or pre-stressed concrete are used. Steel lintels are usually covered by non-structural brickwork and plasterboard so that they are not visible.

Problems with lintels which may be revealed in a survey report include:

• Failure of the lintel - this can occur when a stone lintel cracks or a wooden lintel rots, causing cracking or collapse of the wall above.
• Rust or corrosion in a steel lintel - this can occur when the steel was not treated before installation, or the rust-proofing has broken down. When rust occurs this can cause damage to adjacent brickwork.
• Subsidence of the structure supporting the lintel - lintels rest on the walls of the building, so if these subside the lintel can be left unsupported.

Loam
Loam is soil that is made up of sand, silt and clay. Technically, loam is soil that has 7-27 percent clay, 28-50 percent silt and less than 52 percent sand.

Local Authority Search
A local authority search is one of the essential searches that a conveyancing solicitor will commission on behalf of a property buyer.

This search consists of several smaller searches and requests information on any nearby contamination, road schemes or planning works.

Loft Conversion
A loft conversion is the adaptation of roof space into a habitable room.

Many loft conversions do not require planning permission because they are classed as permitted development but must adhere to building regulations.

Any conversion must meet a number of conditions, including limitations on space and elevation.

Mansard Roof
A Mansard roof is a type that has two slopes on every side. The lower slope of the two is much steeper than the upper.

Market Appraisal
A market appraisal is an estate agent recommendation on the best price that can be achieved for a property going on the market.

Masonry
Masonry is the general term used for the brickwork and stone that forms the walls and other solid elements of a building.

Mastic Sealant
Mastic sealant is a liquid sealant used to bond surfaces, such as wood, glass and tiles.

Most commonly used around window frames, mastic sealant creates a dust-free surface that can last around five years before needing to be replaced.

Mortar
Mortar is a mixture of sand, cement and water that is used in masonry construction to fill the gaps between bricks and blocks. Mortar is applied as a wet paste that hardens when set.

Nail Sickness
In slate roofs, nails are used to secure the slates. Nail sickness occurs when the nails begin to rust and the slates slip.

NHBC
The NHBC provides warranties and insurances for new-build homes in the UK.

A non-profit company, the NHBC offers builders training, guidance and inspection services, and protects homeowners through its Buildmark warranty.

Obsolescence
Obsolescence happens when a property's value falls.

This may be because of external factors that the homeowner cannot control such as the construction of a new road. Or it may be because the building's age or design means it cannot be updated.

A property may also become obsolete because of a lack of maintenance and repair.

Oriel Window
An oriel window is a type of bay window that extends from a building's main wall but not to the ground.

Oriel windows are more commonly used on the upper floors of a building.

Overflow Pipe
An overflow pipe is used to prevent flooding within a home. These pipes are most commonly fitted to a cistern or toilet tank and any excess water is safely released through the overflow into the garden.

Parapet
A parapet is a low wall along the roof of a building or the edge of a balcony.

Partition Walls
A partition wall divides a room or a portion of a room. The partition wall may be made up of brick, studding or glass.

Where a partition wall is also load-bearing, it is referred to as an internal wall.

Party Wall
A party wall is a shared property boundary between two or more owners.

The party wall, also known as the common wall, either forms part of a building or is a garden wall between two or more properties.

Pebble Dashing
Pebble dashing is a type of wall covering for exterior walls that involves throwing and pressing pebbles into a base of lime and sand.

Penetrating Damp
Penetrating damp occurs when moisture develops in the walls, roof or below-ground area of a building.

Planning Conditions
Local authorities have the power to impose planning conditions when granting planning permission.

Broadly, these conditions are designed to enhance a development or planning project.

Planning conditions must be necessary, relevant, enforceable and reasonable. They must also be adhered to.

Planning Search
This search is recommended if you want to find out information about possible private development near to a house you intend to buy.

The planning search will normally be recommended by your solicitor during the conveyancing process.

A local search will not show details of any planning consents or applications relating to any other properties. So you could buy your new home and then find out that a neighbour has already got permission to build a large extension, or even that a supermarket chain has just lodged a planning application to build a superstore on the open land behind the garden.

A planning search will give you details of any existing consents or applications relating to property within a 500 metre radius.

It will also provide details of planning zoning as set out in the council's planning policy. You could find that the open land behind your home is zoned for residential or even industrial use, which means that further development is likely.

Pot Block
A pot block was a type of construction used in domestic buildings in the mid-20th century in the UK.

Property built in this way has known insulation issues and is not suitable for cavity wall insulation. As a result, many mortgage lenders will not lend on such a property.

Purlin
A purlin is a horizontal bar or beam that provides structural support in buildings, usually for the roof, supported by rafters or walls.

Pyramus and Thisbe Club
The Pyramus and Thisbe Club was founded in 1974 to promote best professional practice in party wall legislation and procedure.

The club is named after the characters of Pyramus and Thisbe in A Midsummer Night's Dream where two lovers are separated by a wall and doomed by their fathers' dispute over the wall.

Rafter
Rafters are a series of timber or steel beams that form part of a roof base. The rafters are laid side by side from the ridge to the eaves and are generally, but not always, concealed within the whole roof structure.

Raking Cracking
Raking cracking refers to the cracks that appear in masonry walls.

While they most often form because of normal expansion and contraction in a building, they can sometimes be an indication of a bigger structural problem and should be surveyed thoroughly.

Record of Condition
More commonly known as the Schedule of Conditions, this report factually records the condition of a property on a particular date. The record of condition is often prepared at the start of a lease.

Refurbishment
Refurbishment is the process of improving a building or property through repair, renovation, restoration, cleaning or decorating.

Refurbishment can also include improving a building's energy efficiency, adding an extension or modernising its facilities.

Render
Render is a coat of mortar applied to an interior wall before plastering or on an external wall to weather and waterproof it.

Repointing
Repointing involves removing and replacing the mortar from the face of a masonry joint. Repointing is required to improve the weathering of a wall and stop its deterioration.

Retaining Wall
A retaining wall is used to hold or retain soil.

Reversionary home income plan
A reversionary home income plan is a type of equity release scheme that allows a homeowner to access some of the money tied up in their home.

In such a scheme, the homeowner sells all or part of the property at less than its market value in return for a tax-free lump sum, a regular income or both.

The important part of the scheme is that the homeowner continues to live in their home but this time as a tenant, albeit without paying rent, until death or they move out.

Ridge Tiles
Ridge tiles are placed along the ridge of a roof, traditionally bonded to the tiles using mortar but now more likely to be mechanically secured without mortar.

Rising Damp
Rising damp is a type of dampness that affects a building's wall and is caused by moisture travelling up through the walls.

Once the water has entered the wall, it can spread to other materials such as plasterwork, floorboards, joists and skirtings and show as evidence of wet rot.

Rising damp will often show as tide marks on internal walls.

Roof Truss
A roof truss is the structural framework of timbers that provides support for a roof.

Roofing Felt
Roofing felt is waterproof sheeting uses to cover flat roofs or as an underlay for slate and tile roofing. It can also be used as the final covering on a shed.

Roofing felt is made from bitumen and mixed with sand or crushed limestone.

Royal Institution of Chartered Surveyors (RICS)
The Royal Institution of Chartered Surveyors (RICS) is the world's leading professional body for qualifications and standards in land, property, infrastructure and construction.

Surveyor Local only works with chartered surveyors who are members of RICS.

RSJ
A rolled steel joist of RSJ is a common type of beam used for structural steelwork.

Also known as an I beam because of its shape, an RSJ is used to support a load such as an internal wall.

Sash Windows
Sash windows work on a pulley system, balanced by weights on sash cords. They open by sliding up or down, although some types open by sliding from side to side.

This is a style that dates from the Georgian and Victorian periods

Sash windows may be double hung, meaning you can open both top and bottom windows to improve ventilation, or single hung where only one sash opens.

Schedule of Condition
The Schedule of Conditions factually records the condition of a property on a particular date. This report is usually prepared when a lease term is ending.

Septic Tank
A septic tank is part of an underground wastewater treatment system, often used in rural areas with no access to the main sewer system.

Wastewater is collected in the tank and allowed to soak into the surrounding ground through a series of chambers and pipes.

Sick Building Syndrome
Sick building syndrome (SBS) is a name for a medical condition affecting people who spend time in the same building.

While they suffer from symptoms of illness or feel unwell, there is no apparent medical reason for this.

Its precise cause is unknown, but experts believe poor air quality may be to blame.

Skylight
A skylight or rooflight is placed in the roof space of a building to increase the amount of daylight that can come in.

Soakaway
A soakaway is a system for dealing with surface or excess water.

Traditionally, a hole is dug in the ground and filled with coarse stone and rubble that filters water through it. The water then runs off in a controlled way into the surrounding ground.

Soffit
A soffit is the underside of an architectural structure, such as overhanging eaves or a balcony.

Soil Vent Pipe
A Soil Vent Pipe is a vertical pipe typically (although not always) attached to the exterior of a property.

Soil Vent Pipes connect the subterranean drainage system to a point just elevated from the roof guttering and carry waste from WCs, showers, baths and sinks.

The pipe allows odours emanating from the drainage system to escape into the air at a level that won't affect anyone in the property.

The pipe also serves the additional purpose of allowing air into the internal drain pipe system to prevent a siphoning effect from occurring. This would manifest itself in baths for example.

Soil Vent Pipes are now made of plastic but historically were made of cast iron. Cast iron, albeit aesthetically pleasing, is of course prone to rust. Often this rust is concealed due to over painting and a common problem occurs where the accessible part of the pipe is painted but the side closest to the wall is not. This tends to lead to failure from rust leading to leaks which can affect the wall of the property leading to damp.

Asbestos is also encountered on soil vent pipes on older properties. Please see our section on asbestos for further information.

Solid Wall
Property built before the 1920s in the UK is most likely to have solid external walls rather than cavity walls. Solid walls consist of two layers of brick with no gap in between.

Spalled Brickwork
Spalled brickwork is brickwork that is flaking, cracking, peeling, crumbling or chipped. Spalling is caused by water penetration, heating or freezing.

While spalling is often simply an aesthetic issue, brickwork can deteriorate rapidly as a result and repointing is required.

Specific Defects Report
A surveyor will produce a specific defects report to detail what has been uncovered during an inspection.

The report assesses any structural issues and their causes, while detailing the repairs and their cost.

Stepped Cracking
Stepped cracking in an external wall is caused by movement in both foundation and walls, sometimes through subsidence.

This type of cracking can be seen following joints in the mortar, usually near the corner of a building.

Stock Condition Surveys
Stock condition surveys are carried out at regular three- or five-year intervals by housing associations on their properties.

These reports collate information that relates to the Government's Decent Home Standard and help associations programme future repairs and replacement work.

Subsidence
Subsidence occurs when the ground underneath a building sinks or collapses, taking some of the foundations down with it.

The building sinks to one side, causing cracks to appear in both external and internal walls.

Surface water drain
A drain carrying 'surface water' i.e. rainwater. Surface water drains may discharge either to a soakaway, watercourse or surface water sewer.

In newer properties surface water and foul water are kept apart in separate drains. This is known as a separate drainage system. With this method, foul air is not created in the surface water drains. Older properties frequently have 'combined drainage' where surface water is discharged into the foul drains. Rainwater pipes should discharge to foul drains via gully traps, to stop foul air escaping from the drains.

It is extremely important to ensure that foul water is not discharged into a surface water drainage system. A survey will check that surface water drains are operating properly.

Sustainable Building
A sustainable building, also referred to as green construction, means both a building that is environmentally responsible and efficient in its use of resources throughout its life and also a style of construction that follows the same principles.

Tanking
Tanking is when a seal is applied to a wall to protect against water penetration. Tanking is applied as standard on all new-build properties below ground.

However, tanking can also be done on existing properties' basements and cellars, for example, to repel water and tackle rising damp.

Thermal Movement
Thermal movement is the effects of a change in temperature that causes material to contract or expand.

There are two types of thermal movement that can affect buildings: thermal expansion and thermal contraction.

Thermal expansion happens when a building is exposed to high temperatures; for example, in a bathroom where there is lots of steam from hot water or in a kitchen with hob and oven in use.

Thermal contract happens when the structure is exposed to extremely cold temperatures.

The effects of thermal movement can be seen in cracked brickwork, broken window fittings and sloping floors.

Timber Infestation
Timber infestation is caused when the common woodworm beetle infests indoor timbers and furniture. Unchecked infestations can lead to structural weakening and collapse.

Underfelt
On roofs, underfelt is used to provide an additional waterproof barrier and an extra layer of insulation.

Universal Beams
Often referred to as I beams or H beams because of their shape, universal beams are made of steel and are used in steel and wood frames that need additional weight support.

Valley
The valley is the point or joint at which two different roof aspects meet. This forms a drainage channel known as the valley, which is usually lined with lead.

Valley Gutter
The roof valley gutter is where two main roofs meet or where there is a change in roof direction.

Valuation
A surveyor may be asked to provide a valuation report on behalf of a lender.

This valuation is based on issues that might affect a property's price, including transport links, school catchment, local environment and flood areas. The valuation will also include a physical inspection.

A surveyor's valuation differs from an estate agent's market appraisal; the latter is based on the agent's assessment of what the property might fetch in the local market.

Verge
In reference to the roof of a property, the Verge is the edge of a gable roof, where the tiles of the gable roof meet the gable end wall. The roof verge acts as seal to hold the tiles in place, so it is important that this element of the roof is well maintained.

As with many external parts of a house, the mortar of the roof verge will deteriorate over time, particularly in wet and freezing conditions. If cracks appear in the mortar, or it starts to crumble, action must be taken. The damage will quickly worsen, and will soon compromise the structural integrity of the roof.

Vertical Cracking
Vertical cracking can be evidence of benign settlement of a property, particularly in the case of newly built homes, or a more worrying sign of foundation movement. Cracks commonly occur near door or window frames, where the wall structure is weaker.

Small vertical cracks which appear in both external and internal walls and which are the result of normal settling can often be simply filled in. New build property developers will often arrange for a builder or other specialist to check the house some months after construction has completed for superficial issues like these, and make good any issues.

Is a Vertical Crack dangerous?

In general, vertical cracking is not an indication of deeper problems unless it is accompanied by lateral movement or bowing of the wall, or the crack is noticeably uneven. A property surveyor will also check that both sides of the crack are on the same plane. If displacement of one side of the crack has occurred relative to the other, a serious structural defect may be the cause. As all materials will expand and contract to varying degrees, it is not possible to entirely prevent this cracking in a new property. Where cracks suddenly appear, or widen, in an older property, the professional advice of a builder or surveyor should be sought immediately.

If the cracking is a result of subsidence or heave, the structure of the whole property is at risk, and may require substantial and costly work to remedy.

Wet Rot
What is Wet Rot?
Wet Rot refers to a number of different species of fungi, mostly commonly Coniophora puteana (brown rot), Phellinus Contiguus (white rot) and Poria vaillantii. Coniophora is found in many homes where damp timber has suffered some degree of decay. Though the specific type of fungi may vary, they are broadly similar in appearance and as the treatment is the same, there is no need to identify the particular species attacking your home.

The fungus can take root when microscopic spores, spread on air currents, come into contact with damp, untreated wood.

Wet Rot is less destructive than dry rot, as it tends to be confined to the damp timber itself, and will not invade walls otherwise. The threads (mycelium) of the fungus burrow into the wood, and begin to break it up to digest it. As a result, Wet Rot can compromise the integrity of the structural beams of a home, and can thereby become very serious if not treated.

Is Wet Rot a health risk?
Other than the damage wet rot can cause to a house's structure, wet rot is not commonly associated with major health concerns. The spores may cause or trigger asthma in children, or similar respiratory issues, however, so it is better to seek a solution as soon as is practicable.

How to treat Wet Rot?
As with dry rot, Wet Rot must be identified and treated by a professional. Preventative steps can be taken, such as ensuring timber is painted or treated appropriately, and well ventilated, but once the rot has set in, it is advisable to call in the professionals.

A surveyor or builder will seek to remedy the issue by solving the underlying damp problems. This can include better ventilation, identifying the source of any leaks, such as poor guttering.

Wood Boring Insects
There are a number of species of Wood Boring Insects which have been found in the UK, including the House Longhorn Beetle, Common Furniture Beetle and Deathwatch Beetle.

It is the larvae of these species which are generally the most troublesome, and may only be identified by small, regular holes in beams or furniture. Although the damage may appear trivial from the outside, wood boring insects which have been active in a property for some time will 'hollow out' beams, making them far weaker than they appear, and putting the entire structure of the house at risk.

For example, the House Lornhorn Beetle larvae can spend between three and eleven years burrowing through timber.

Some species will only truly infest living wood, making any sign of their presence in a home superficial. However, damp, poorly ventilated conditions, such as in roof spaces or behind walls, can be ideal conditions for others to thrive.

Treating Wood Boring Insects:

A number of treatments are available, depending on the specific infestation and the scope of the problem:

• Targeted use of pesticides or insecticides
• Freezing or heat treatment (this may only be suitable for isolated timbers or furniture)
• Fumigation of a property

It is strongly recommended that an expert surveyor or specialist be contacted prior to attempting any remedy. Improperly executed treatments can result in further damage, and in some cases, severe health problems. Some of these methods can be very disruptive, making the successful identification of the problem during a survey particularly useful. Any remedial work can then take place before you move in.

Wood Rot
Wood Rot can refer to the fungal infestation of the timber elements of a property, particularly structural beams. Also called Dry Rot and Wet Rot, Wood Rot is relatively common in homes throughout the UK.

Wet Rot is generally less serious than Dry Rot, which can quickly cause severe structural damage, but both should be treated promptly. Seek a surveyor or other expert's advice before attempting any treatment.

See Dry Rot or Wet Rot for more information.

Woodworm
Woodworm is the common term for the larvae of all wood-boring beetles. There are several different species of beetle in the UK.

However, the majority of woodworm in domestic property is caused by the common furniture beetle.

An untreated infestation of woodworm can destroy timber and furniture.

Yield
For property investors, yield is how much of an annual return on their investment they can expect to receive.

Yield takes into account rental income, fees, repairs and running costs to produce a net yield or profit.

Zinc Roofing
Zinc Roofing was once very popular in North America, but is becoming increasingly common in England and Wales. Although generally a versatile material to work with, prior to the installation of zinc either as replacement for part of a roof, or in the construction of an extension, a survey will be required to determine that an adverse reaction will not occur. Though uncommon, it is possible that other materials used in a home's construction may damage the metal.

Zinc metal is still a relatively new roofing option for home builders and owners, with several advantages over more traditional methods. The metal is very resistant to weather and environmental conditions, such as frost or hail, and is lightweight, putting less strain on a property's structural integrity. It is often chosen for its environmental benefits too, as the material had an extremely long lifespan, and can be completely recycled.

Zinc is also suitable for more unusual construction, as it can be more easily shaped than some metal roofing materials. It can be expensive to source, which has contributed to its slow uptake as a staple building material. The durability and long life of the metal may offset this cost, however.

Zurich Warranty
The Zurich warranty is a 10-year building warranty and insurance policy that is similar to NHBC's Buildmark.

In 2018, Zurich Insurance transferred its UK building guarantee business to East West Insurance Company.