‘Rising dampness’ is a phrase that many buyers and building owners dread to hear. It conjures up images of a damp, dilapidated property that will be expensive to repair and difficult to sell. Yet many homes with a dampness problem fall far short of this dramatic description. In the majority of cases, the problems are caused by relatively minor faults. Despite this, every year tens of thousands of dwellings undergo expensive repair work to cure a problem that an increasing number of experts say is not that serious.
What is ‘rising dampness’?
Water in the ground rises up through the bricks and mortar of a wall by a process called ‘capillary action’. If the wall does not include a horizontal water proof layer (called a damp proof course), this rising moisture will eventually affect the internal parts of the home. In the worst cases, it will ruin decorations, cause the plaster to crumble and adjacent timber surfaces to rot. On the inside, it can look like the base of the wall is stained with a ‘tide mark’ that has white furry salt crystals along its edge.
Does rising dampness exist?
Although capillary action does occur, it is unlikely to result in dampness reaching these levels on its own. Instead, the dampness is often ‘helped’ along its journey by other faults including high ground
levels, leaking drains and gutters, and inappropriate wall finishes that stop the wall drying out (for example, cement render). Repairing these problems will often solve the dampness.