RetroFoam™ for Block / Cavity Walls

A traditional construction brick / block cavity wall usually consists of two 'skins' separated by a hollow space (cavity). The skins are commonly masonry such as brick or concrete block. Masonry is an absorbent material, and therefore will slowly draw rainwater or even humidity into the wall. The cavity serves as a way to drain this water back out through weep holes at the base of the wall system or above windows. A cavity wall with masonry as both inner and outer skins is more commonly referred to as a double wythe masonry wall.

The cavity wall method of construction was introduced in Europe during the 19th century and gained widespread use from the 1920s. In some early examples stones were used to tie the two leaves of the cavity wall together.

Initially cavity widths were extremely narrow and were primarily implemented to prevent the passage of moisture into the interior of the building.

The widespread introduction of insulation into the cavity began in the 1970s with it becoming compulsory in building regulations during the 1990s.

Installation of RetroFoam in traditional cavity walls as opposed to timber framed construction is equally effective and follows a similar method whereby the cavity wall is injected with RetroFoam by drilling holes in the external wall, through the mortar joint. Holes are generally of 22-25mm diameter and are 'made good' after injection.

The whole process is typically completed with a day.

There are numerous government grants and schemes which may help homeowners spread the cost of the cavity wall insulation - please feel free to contact us to speak with one of our insulation specialists to see if any of these are applicable to your home.