Can I insulate my cavity?

If your cavity does not contain any insulation material, it’s best to insulate it. However, you can only do this if the exterior wall, facing bricks, cavity and joints meet a number of conditions. Otherwise, additional work will have to be performed first. We have listed the conditions below.

Bear the following in mind before insulating a cavity:
 

• The cavity must be large enough

The cavity can only be filled if the space available in the cavity is large enough. It needs to be at least 5 centimetres wide. If this is not the case, the insulation material cannot be evenly distributed, potentially leading to moisture problems. The cavity should also be wide enough to ensure that the insulation material can adequately minimise heat loss.
 

• Facing bricks should be in good condition
• The cavity should be dry, clean and stable
• Joints should be in good condition
• The exterior wall should not have any cracks or openings
• The exterior wall should not show any signs of moisture problems or organic contamination
• A painted exterior wall should be painted using breathable paint
• The exterior wall should consist of permeable bricks or tiles
• The exterior wall should not be plastered

If the exterior wall has been plastered, painted using non-permeable paint, erected using glazed bricks or covered with ceramic tiles, condensation in the cavity has no way out. This will impair the insulating properties of the insulation material and make it prone to moulding.

You should engage a specialist company that can ascertain whether these conditions are met. If that is not the case, any problems that have been detected should be remedied, if possible, before you can insulate the wall.