Cavity wall insulation and damp are usually referred to together, especially on online forums, but although the two can be linked, having cavity wall insulation does not cause damp. It can make an existing damp issue more apparent however.

By installing cavity wall insulation you are not putting up a barrier to prevent water getting to the inside wall of your house – that’s what the outer wall does. Any moisture will move down the layer of insulation due to gravity and once it descends it can spread out and act as a channel between the outside and the inside wall.

Damp issues are caused by the condition of your outer wall so any issues with brickwork, brick pointing and leaking gutters should be resolved before having cavity wall insulation installed.