What is Rising Damp?
Rising damp is the process where moisture flows upwards through the pores of a masonry wall looking for a way to evaporate. Moisture will keep rising until it evaporates. If evaporation is not possible, gravity will take over and pull the moisture down.
A masonry structure that is left unprotected by appropriately installed course that prevents rising damp will eventually succumb to naturally rising damp.
What happens when damp is rising through your masonry wall?
The rising water contains water salts, which are deposited in the masonry and other surfaces like decorative finishes and plaster. The wallpaper will peel, plaster will deteriorate and paint will blister.
Erosion of the Building Fabric
Over time, these salt deposits continue to rise and eventually build up to high levels. Excessively rising damp will cause a rot in floor joists, skirting boards, wall plates and floorboards in suspended timber floors. Eventually, the structure will lose its structural integrity and strength.
Increased Heat Loss
Damp reduces the insulation properties of building materials as conductive water replaces the air in the pores. The increased heat loss reduces the surface temperature of a wall and increases the risk of condensation.
Excessive dampness has a lot of deteriorating health effects. Too much moisture can result in a stuffy environment and also results in faint odour.
What Causes Rising Damp?
Damp rises when moisture from the ground gets sucked into the porous building materials. The height of the rise is exceptionally high when the moisture evaporation is restricted, such as:
- Colder climates
- Walls located in northerly aspect are cooler and hence susceptible to higher rise
- Unheated or unoccupied homes limit evaporation
- Thick walls also inhibit evaporation as the surface area is lower