Millions of homes across the country have had Cavity Wall Insulation fitted which Is proving be causing damp and other more serious problems, which might not show for some years to come. The BBA issued guidelines that should have been followed by contractors doing the install which were not, some of the many examples include the following:

  •  An active damp course was not in place.
  •  Joining property walls were not brushed off.
  •  Property should not have been insulated.
  •  Cavities were not cleared of debris prior to install.
  •  Not enough or incorrect insulation materials were used.
  •  Damaged brickwork was not repaired prior to install.

If your property didn’t get the proper pre-survey and pre-treatment or a stub-standard installation, damp problems may already be present or can lurking unknow to the house owner and may not show for some time. Your property might only be part insulated or some walls missed out all together.

What is Wall Cavity Insulation?

If your house was built after the 1920s, it is likely to have cavity walls. Older houses are more likely to have solid walls. If your home was built in the last 10 years, it was probably built with insulation installed at the time.

If you can see the brickwork on the outside of the house, look at the pattern of the bricks. If your home has cavity walls, the bricks will usually have a regular pattern similar this:


If your home has solid walls, the bricks will have an alternating pattern like this:


If the brickwork has been covered by render, you can also tell by measuring the width of the wall.  Examine a window or door on one of your external walls. If a brick wall is more than 3000mm thick, (from the outer wall to inner wall) then it probably has a cavity; a narrower wall is probably solid. Stone walls may be thicker still but are usually solid.

If your house is a steel-frame or timber-framed building, or is made from pre-fabricated concrete, different rules apply for insulation and this should be surveyed by a specialist before and if any insulation is fitted.

Modern technology tells us that up to 40% of our home energy heat can be lost through a cavity wall if not insulated. A Government backed scheme aimed to help fill these cavities with insulation and keep our homes warmer while reducing the amount of energy needed to warm our homes, and have a better impact on energy saving.

The product itself is really good, if the property is suitable and the installer has done proper pre-checks and installation, the difference can be outstanding. Millions of homes had the cavity wall insulation installed and it is estimated up to 3 million homes may be at risk of serious damp issues or even structural issues and health risks where the installation was not carried out to the agreed specifications.

If a cavity is not filled 100% compact, void areas can gather moisture and lead to damp. Where a cavity is not fully clean and cleared of debris, this can bridge the gap and again introduce moisture and cause damp. The lack of ‘brushing off’ a cavity that joins a neighbour’s property means insulation may seep out into the next door cavity and lead to voids in your walls, or cross contaminate if different materials are used. An active damp course should be in place to keep the damp to ground level and not reach the cavity wall insulation as this can soak and travel up the walls causing damp. There are many other reasons why incorrect installation can cause damp and other problems.

Those who installed the cavity wall insulation should have carried out a pre-survey assessment to ensure the property itself was suitable for cavity wall insulation and subsequently assessed that there were no hazards present that could cause failure and problems of the cavity wall insulation later down the line.

HelpHDR is a legal services company who offer a free survey to assess your cavity wall insulation and ensure it was installed correctly, and if not, we have access to specialist panel solicitors who work  No Win No Fee.