The heat is on: how hot weather affects home surveys

We started this year with most places seeing over a month of successive wet days and rather cool, if not freezing, temperatures. Unusual weather events like this are becoming even more frequent as a direct result of climate change.

Now that we've officially entered summer and just stepped over the longest day of the year, we're already experiencing our second major heatwave of the year. The problem isn't necessarily having successive days of hot weather. This country has a history of that. It's that we're increasingly seeing long heatwaves where temperatures break weather records. Just this week, we've experienced the hottest day on record, with the possibility of that being broken again within days.

From an economic point of view, this is also a problem. Reservoirs can dry up and crops are affected by oppressive heat, especially following a sequence of very wet months.

We're generally well prepared for the impact of wet weather in this country, simply because we're so used to it. This matters when it comes to booking a survey for a planned property purchase. Whether it's subsidence caused by rainwater flushing away the soil around foundations, or the perils of flooding, dry rot, wet rot, damp and rotting timbers, the points a survey raises around extensive rain are reasonably well understood by most homebuyers.

But what about the impact of increasingly hot and frequent 30-degree-plus heatwaves, beyond the obvious struggle to keep cool and get a good night's sleep?

One of the less obvious problems is timber doors and windows sticking. This might seem counter-intuitive. Surely hot sun dries materials out? Unfortunately, as an island nation, our hot periods tend not to be dry. Surrounded by water, our hot seasons are usually humid, which makes the atmosphere quite uncomfortable as the heat drags moisture in from the surrounding sea. That increased humidity means more moisture in the air, which is absorbed by various materials including wood. Poorly maintained windows and doors are the ones most likely to stick as a result.

Subsidence is most commonly associated with extensive wet periods, but heat plays a role too. As temperatures rise, moisture evaporates from the soil, producing those familiar cracked surfaces. It can also draw moisture away from the foundations, and the weight of the building may cause the property to settle into the void left behind. Plants searching for water send out longer roots, drawing moisture from further afield and drying out the soil around foundations even more.

Building materials contract in cooler weather and expand in warmer weather. In heatwaves, that expansion goes further still. Since most materials weren't built with these extremes in mind, the continual expansion and contraction can eventually cause fatigue and cracking. This is a particular problem for roofing and rainwater management. If a material is damaged during a heatwave, the next wet spell can be when damp and flooding take hold.

This might sound alarming, but we're talking about extremes, even if those extremes are rapidly becoming the norm.

When you're buying a property, it's worth taking out a survey so you get an expert assessment of the home's condition. One of the things a chartered surveyor will look at is the condition of the materials used to build the property, checking for evidence of problems caused by a number of factors, including excessive heat.

So before you decide to skip the survey, think about the problems that might be present in a property, many of which you wouldn't necessarily notice yourself. To understand the condition and structural integrity of a home you're planning to buy, book a survey with Surveyor Local. Your chartered surveyor will take on your specific requirements for further investigation, whatever your concerns, so you're clear about exactly what you're taking on.

Surveyor Local connects you to professional advice through our nationwide panel of chartered surveyors, all of whom are RICS members, ensuring your survey is always delivered professionally and will identify all kinds of problems, including the impact of prior flooding on a property's structure.

Call to get your no-obligation survey quote started, or to talk through any concerns about the property you're planning to buy. Or get a quick quote using Surveyor Local's easy-to-use quote generator.