Crawley Council Owned House - Cavity Insulation Protection

This property is owned by the Crawley Borough Council, for use as a rented home. It is a standard brick built cavity wall construction made in the mid-1960s. The building itself forms two semi-detached homes and is one of many very similar houses in the local area. The properties are set at a slight angle from the road, leaving the gable end exposed.

The Problem

Cavity wall insulation had been installed on the south-west facing gable end wall. Due to a multitude of factors, such as the severe and prolonged wet weather during the previous winter and the steadily deteriorating condition of the mortar, water had penetrated the brickwork and severely dampened the cavity wall insulation.

The cavity insulation transmitted a large amount of water to the interior leaf of the cavity and led to severe damp patches and mould growth on the interior décor. When the wet weather stopped and temperatures increased, it was found that the inner leaf of the cavity and the insulation did not dry out and the damp patches remained. Crawley Borough Council was called in to survey the situation.

The Solution

After the property had been surveyed it was decided that the best course of action would be to remove the cavity wall insulation, repoint the entire gable end, install new cavity insulation and then apply a treatment of Stormdry Masonry Protection Cream.

The removal of the original cavity wall insulation was completed using cavity insulation specialists Downs Energy. After the removal of the wet insulation a proper assessment of the condition of the wall was performed. It was found that, over the years, the mortar of the brickwork had significantly degraded and become cracked and porous.

After the wall was cleaned, the mortar of the entire gable end was raked out and repointed using a more suitable mortar mix with repointing additive. When repointing, before the use of Stormdry Masonry Protection Cream, it is always advantageous to use Stormdry Repointing Addtives. They reduce shrinkage whilst the mortar cures and ensures a more complete bond with the brickwork.

Once the repointing had been completed and new cavity wall insulation installed, the Stormdry Masonry Protection Cream was applied with roller and brush. The application was completed in a single morning and ensures that the tenant will enjoy the significant thermal benefits of cavity wall insulation for 25 years, without the worry of penetrating damp.