What Is Cavity Wall Insulation?

K.C. Bruning

Cavity wall insulation is material used between two exterior walls in order to retain heat and lower energy usage. The insulation comes in a wide array of natural and synthetic materials and can be installed in panels or as a loose substance. It is usually placed between either two exterior layers of brick or one exterior layer of brick and an interior layer of cement blocks. Cavity wall insulation is typically installed during construction of a building, though it can be inserted into an existing structure.


There are several different kinds of material commonly used for cavity wall insulation. Panels of rock wool, glass fiber wool, or polyurethane are commonly used for insulation in a new building. As it can be nearly impossible to install panels between cavity walls in an existing structure, it is common to blow loose materials such as foam, cellulose insulation or glass wool into the walls until they are sufficiently filled.

Some governments offer grants and other incentives to builders and owners who insulate cavity walls. As it is an energy-saving measure, cavity wall insulation reduces the use of community resources. It also helps to reduce the emission of carbon dioxide, which can be harmful to the environment.

Cavity wall insulation can also be cost effective for the owner in the long run. In addition to the money it saves by retaining heat, insulation can help to make overall heating more effective, thus reducing the amount of energy needed to warm the building overall. It is generally believed to be an effective way to update a home and increase its resale value as well.

In order to install cavity wall insulation in an existing structure, it is first necessary to ensure that a cavity exits. This can be determined by examining the formation of the corner bricks. If there is an end brick, there probably is not a cavity. When the bricks are laid lengthwise all the way to the corner, it is more likely that there is a cavity.

Once it has been confirmed that there is a cavity in a wall, holes are usually made in several spots along the wall. These are filled with insulation via a hose that is inserted into each hole. When all sections of the wall have been filled, the holes are refilled with mortar or whatever other material will match the exterior. A project of this nature typically takes only a couple of hours to complete.

You might also Like

Readers Also Love

Discuss this Article

Post your comments
Forgot password?