So why were buildings built with wall cavities? Well, homes and other buildings made from the 1920s and onwards were made with cavities to prevent rainwater from penetrating through the outer wall to the inside of the property. However, the cavities let heat escape, so you’d be spending extra pennies to make your property warm and cosy this winter.
How do you know if your walls have cavities? Well, there are several ways to check. Firstly, find out when your property was made. If it was in the last 20 years, then there’s a very high chance that you will have cavity wall insulation and you don’t need to worry about anything. However, if was built post-1920, then it’s likely to have cavity walls.
You can also measure the thickness of the wall: if your wall is more than 260mm thick at an outside door or window, then it probably has a cavity. Looking at your brickwork may also give you an indication of whether you have gaps in your walls. If the outer brickwork forms an even pattern with every brick laid lengthways, then they will probably have cavities. However, you will have solid walls if the bricks are in an uneven pattern, with some bricks being laid endways instead. Pre-1920 houses and buildings are more likely to have solid walls and won’t have any cavities.
Some houses and buildings have a completely different type of wall structure altogether. They may be built using a steel or timber frame, or constructed using prefabricated concrete.