A guide to cavity wall insulation

Many houses in the UK (particularly those built prior to the 1990s) tend to lack wall insulation, meaning that up to a third of a house’s heat escapes through the walls more easily. In UK housing, most houses built from the 1990s onwards tend to already have wall insulation installed to reduce heat loss. 

Older buildings however, may not have any insulation at all. Post-1920s buildings are more likely to have cavity walls.  These walls are made up of two walls with a gap in between, with an outer layer made of brick and inner layer made up either of brick or concrete block. On the other hand, pre-1920s buildings tend to have solid walls. These walls have no cavity, just a single solid wall made of either brick or stone.

Enter cavity wall insulation. Cavity wall insulation contains heat within the inner walls of your house, reflecting it back inside into the room(s) and keeping it inside for longer. This results in more even temperatures and eliminates draughts from the walls. Most cavity walls can be insulated by drilling 22mm wide holes into the exterior wall (usually spaced 1 metre apart) injecting the insulation (generally polystyrene beads or mineral wool, though polyurethane foam is sometimes used) and then sealing the holes up with cement.

There are numerous benefits to cavity wall insulation, you save energy and on your heating bill, all while lowering your carbon footprint. This can result in savings of up to £275 annually, depending on the type of home.

There are two types of cavity wall insulation; partial fill and full fill, both of which can be purchased from InsulationBee. Partial fill sees the cavity between the two wall layers partially filled with insulation, while full fill sees the cavity completely filled with insulation.

When it comes to installation, you need to work out the type of walls your home has. Luckily, this can be solved by examining the pattern of the brickwork on the exterior of the house. Cavity walls tend to have an even pattern with the bricks laid lengthways, while solid walls have an alternating pattern with some bricks laid across the wall, meaning that the smaller ends are visible from the outside. 

Following this, it helps to get a survey from your installer to determine whether your house is suitable for cavity wall insulation. If your home’s walls are unfilled with a clear cavity of at least 50mm with no rubble, with the masonry and brickwork still in relatively good condition then it will be suitable for cavity wall insulation.

At InsulationBee, we stock cavity wall insulation from manufacturers Recticell and Xtratherm; buy yours with us today at www.insulationbee.co.uk or speak to one of our friendly staff on 02038839057