Cavity Wall insulation and dampness
Cavity wall insulation does not cause dampness. Cavity walls were introduced originally to avoid the problems of dampness experienced by older solid walled dwellings. Some people think that filling the cavity (which is in effect bridging the gap between the two leaves of the cavity wall) will lead to a greater risk of dampness passing from the ‘wet’ outer leaf to the ‘dry’ inner leaf. In fact, this is not the case. The insulation repels moisture. A government sponsored independent study carried out in the mid 1990s found that filling the cavity with insulation results does not cause a greater incidence of damp problems than occur in cavity walls that have not been filled with insulation.