CWI FAQs

Further information on CWI is available in our fact sheet and we also publish guidance on how to get the best out of your installation.

What is a cavity Wall ?

Since the early 1900’s many house walls have been constructed of two masonry (brick or block) walls, with a cavity (gap) of at least 50mm between. A cavity wall can generally be recognised by it’s thickness (more than 11.5″), or by the brick pattern. The presence of end bricks in the face suggests that the wall may not contain a cavity and is not suitable for cavity wall insulation.

Is my House Suitable for Cavity Wall Insulation ?

Before the installation, the installing firm will undertake an assessment of your property to confirm that it is suitable for insulation. This assessment may be undertaken by a surveyor or the Technician before installation.

How long does it take?

Cavity wall insulation normally takes around two hours to install, but the time does depend on the size of the house and other factors, such as access.

What about filling the holes?

All the holes through which the insulation is injected are filled with mortar to match the existing color and texture as closely as possible. On pebbledash finishes, pebbles are added to the surface to match the existing finish. After weathering, the holes are difficult to see.

How can I find a registered installer?

CIGA maintains a list of registered installers who can offer the CIGA guarantee. You can check for installers in your area by clicking here.