A cavity wall is a space or gap between two separate thin walls usually made of bricks, as opposed to having one built solid wall. These cavity spaces are empty unless filled with insulation material, which is usually mineral fibre wool, cellulose, foam or expanded polystyrene (EPS) sheets or boards.
Insulating cavity walls is a very cost-effective way to retain heat in the building and save on energy bills because most heat loss happens through the walls. If your building has empty cavity walls, chances are you may need to insulate the cavity.
You may be able to determine if the building has solid walls or cavity walls by looking at the thickness of the outer wall, or the way the exposed bricks pattern. For example, solid walls tend to be fortified with bricks laid across, rather than along the wall.
Most brick constructions build in the past century are likely to have cavity walls instead of sold walls. However, in most recent years, these cavities may have already been insulated while building. If this is not the case, cavity walls insulation can still be done, providing that the cavity is suitable for insulation.
Expanded Polystyrene (EPS) manufactured by the Isowall Group is fast becoming recognized as the insulation material of choice by specifiers of “Bills of Quantities”. This comes largely as a result of our technical knowledge backed up by years of experience in the building and construction industry.
You should only consider cavity wall insulation in the following scenarios:
- The building has unfilled cavity walls made of brick
- The cavity is at least 50 mm wide
- The cavity walls brickwork is in excellent condition with no visible cracks
- The internal walls are dry and not exposed to the elements
- The external walls are accessible to insert the insulation
- There are no areas of steel or timber-framed construction
There are particular cases where cavity insulation is not recommended and cannot be done. Stone-walled homes and timber-framed buildings are not suitable for cavity insulation.
Also, if internal walls are wet or damp, the cavity insulation can only be installed after the situation is remedied and the walls become dry. If the walls are regularly exposed to rain or draining water, cavity insulation cannot be performed.
Depending on the case, if some of the walls are inaccessible or joined with another building, the insulation can still be possible and requires a cavity barrier to be inserted first at an additional cost.
Professional and qualified installers should always check out if the walls are suitable for cavity insulation, in good condition and dry before filling the cavity with insulation material.
The Isowall Group has been manufacturing and distributing Isolite Block Moulded EPS since 1985, and Isolite Shape Moulded EPS since 1992. Isolite EPS products are used primarily for insulation, lightweight fillers and semi-rigid cushioning.
Isowall is the supplier of choice within Africa for Insulated Sandwich Panel, EPS and EPP products. Contact us for more information.