Good Repair Guide: Damp subfloors

In a series of house condition surveys that BRANZ carried out on randomly selected houses around New Zealand in 1994, 1999, 2005 and 2010, all of the surveys identified a lack of subfloor ventilation and subsequent higher moisture levels as a problem for houses with suspended floors. Of the houses surveyed, 66% did not meet current requirements for ventilation while 33% had less than a third of the current requirements. The resulting high level of moisture was a significant factor in visible deterioration such as corrosion and decay.

This Good Repair Guide looks at the consequences and causes of subfloor dampness, rules and regulations, health and safety and solutions for subfloors.