Cavity Wall Insulation

03 January 2019

Have you had Cavity Wall Insulation installed?

Cavity Wall Insulation (CWI) can be a great way to keep your home warm and reduce your energy bills – however, it is not suitable for all properties and can bring its own problems to your home.

CWI carries a number of risks, some of which are set out below:-

Slumping Insulation

Some of the first CWI employing more rudimentary materials, has now slumped in the cavity wall, leaving cold spots that may be causing condensation.

Urea Formaldehyde

This form of CWI was used for a period of time in many thousands of installations. Over time it loses its insulation properties, and in the process can present health risks due to gases which are released as it degrades.

Poor Workmanship

Of late, unfortunately, we see many cases of poorly installed CWI where the wrong drill pattern or blowing pressure has left cold spots which may lead to condensation. Other poor installation practices, such as not dealing with wall vents properly, can cause similar problems.

Flood/Water Damaged Insulation

CWI may have been damaged during flooding or through damaged drains allowing water to penetrate the cavity, soaking the CWI or the property may be located in an area of high exposure to wind driven rain i.e. coastal or exposed areas. If cavity wall insulation becomes wet or damp it will transfer moisture to the inner skin of the property, damage wall finishes and potentially cause health hazards.

Unsuitable Building Type

A building, or a particular wall, may have been unsuitable for cavity wall insulation in the first place. Examples can be buildings with porous brickwork or mortar; steel and timber framed buildings; or buildings with high exposure to moisture or cavities with mortar/debris present.