Benham Preservation have been fixing problems associated with dampness for over 40 years, but this page is purely for your information. So how does damp and moisture start and more importantly what sort of damage can it do.

Air in domestic places will always contain some water vapour. The amount of vapour in the air at any time is expressed as humidity relative to the maximum possible in air at that temperature (RH). The maximum varies with temperature, as warm air has a greater water vapour holding capacity than cold air. If the temperature of humid air drops, i.e. when the heating is switched off the temperature may fall below the dew point temperature for the water vapour content present, and condensation will occur. This is particularly prevalent on the coldest surfaces, such as glass and damp walls and areas where stagnant humid air can accumulate, i.e. in built-in bedroom cupboards.

• breathing

• cooking

• washing clothes

• air drying of clothes

• using paraffin or calor gas heaters, etc.

One method of removing this vapour-laden air from houses is by ventilation; by keeping windows open or by having draughts through ill fitting doors and windows, open fires and chimneys. However, the general tendency is to seal up these draughts using double glazing or draught-proofing and sealing up disused chimneys.