If your home was built after the 1920’s chances are it’s got cavity walls and unless it was built since the mid 90’s those cavities are probably empty.
CWI can be a very cost-effective way to retain heat in your home and save on your energy bills. Around a third of heat loss from most homes is through the walls. The gap in a cavity wall should be roughly “2 inches or 50mm” separating two walls (usually brick, and known as ‘skins’ or ‘leaves’ and are held together by metal wall ties.
How can I tell if I have cavity walls?
A clever way is look at the exposed brickwork outside walls, if the bricks all look the same shape and size in pattern ie rectangle then rectangle this means there is a cavity. If the pattern is rectangle, square then rectangle and so on then the walls are solid. If all the brickwork in your home has been rendered or cladded so you can’t see any brickwork, you may be able to tell from the thickness of the outer walls. Check the windows and doorways: if a brick wall is more than 10 inches thick, it’s probably a cavity wall.
How can I tell if my walls have already been insulated?
Ask a registered installer to drill a small hole and perform a boroscope inspection. Check with the building control department of your Local Authority. They should have records of your walls been insulated. Installers will have drilled 1-inch holes at regular intervals when inserting the CWI. Although filled, you will notice faded marks. Also check in attics to see if any material has spilled out at the wall top, this should be sealed straight away. After a thorough inspection first, a professional installer should be able to complete the work in around 2 hours.
You should receive a CIGA guarantee and written confirmation the work complies with building regs from the installer. Your local authority or CIGA may also carry out a spot check to make sure the work is of an acceptable standard.