Rising damp is moisture present in your walls, as a result of water in the ground underneath. Whatever form it takes, damp is a serious matter, and can have far-reaching effects not only on the structural integrity of your home, but your family’s overall health as well.
When there is dampness on your walls, the thermal efficiency of your home is greatly reduced. So, how do you stop damp on external walls for good?
To answer this question, first need to explain the topic of rising damp in more detail, including: the causes, the signs, and lastly, what you can you do to prevent it…
What is Rising Damp?
The simplest way to explain rising damp is water which rises up the wall of a building, in the same way that oil rises up through the wick of a lamp. Bricks and mortar can be very porous, and the water can rise through their many fine capillaries.
Now, while penetrating damp is the most common form of damp, you should also protect yourself from rising damp as well. And some insulation materials offer a two in one solution to both problems. But more on that later.
Water travels upwards, as a result of capillary action. Capillary action is when water is sucked through a small opening. The water usually stops rising at a height where gravity counteracts the upwards force. This is usually a height of 1.2m, but in some instances, it can go even higher.
What Are The Causes?
One of the main reasons why rising damp occurs is due to the lack of a damp proof course. Even when the damp proof course is installed, faulty installation will still lead to rising damp.
What is a damp proof course? It is a waterproof layer in your wall, or in both walls if you have a cavity wall as well. The damp proof course is usually installed six inches from the outside ground on the external walls.
In some cases, the DPC might function well, but the DPC might be breached. That is when something attached to your walls allows water to travel around the damp proof course. For example, an outside structure, like steps attached above the DPC.
Another cause for rising damp is debris present in the cavity wall. The debris bridges the damp proof course, and allows water to travel around, and into the walls.
Sometimes, the damp stems from another source altogether that you may not be initially aware of. In this instance, your best plan-of-attack is to list potential sources one by one, and eliminate them one by one as you conduct a more detailed investigation of the walls.
Damp and Mould:Telltale Signs
One of the common signs of rising damp is a tide line of yellowish or brownish staining, in the lower area of your walls, just above the skirting board.
You might also notice white and fluffy deposits in the plaster. That is the salt debris we talked about previously.
When damp evaporates from your walls, it leaves a salt deposit behind. This is as clear signal that you have a problem that needs addressing asap.
Damp and Mould: How To Treat It
The first step you need to take is to identify the problem. As mentioned previously, you cannot deal with the effects without first finding the cause.
Some people opt for a quick fix, which is repointing, or painting over the damp. But that is just a temporary solution to the problem. Don’t be deceived: You haven’t solved your dampness problem long-term-you’ve just masked it.
The best way to treat the problem is to install a damp proof course, and/or external wall insulation.