Damp - how to find and solve its main causes
April 17, 2009
With an average annual rainfall of 25,000 gallons (113,650 litres) per year, it is no surprise that one of the most common problems experienced by UK homes is damp. Whilst the problem is quite often easy to fix, it can be an indication of a more serious cause. Our aim is to help you find and solve the main causes of damp.
What are the main causes of damp?
Leaks:- If you notice localised damp (in one area of one wall for example), the cause may often be a leak.
- One of the most prevalent causes of localised damp is faulty guttering and down pipes. Begin your investigative work by checking these. Make sure the guttering is clear of any debris such as leaves and moss for example. Test the flow of water through the guttering by filling it with water; this will also help identify that all the joints are tight. If the joints are found to be faulty either seal them or replace them;
- If you have a flat roof, check that the felt is sound;
- If you have a damp chimney breast, check the flashing and tiles around the chimney stack to make sure you have a snug fit;
- If the damp is below a window, check the windowsill and window frame. Badly fitting frames can let damp penetrate the room, as will a bridged drip groove on a windowsill.
Other causes of Damp
If none of these seem to be the likely cause of localised damp, make sure the damp proof course is not bridged.
- Unwittingly, we can pile earth for example against the house, which can allow water to penetrate above the damp course. If you are not sure where a damp proof course is located, go outside your home and examine the brickwork. Approximately 150mm above the external ground level (2 brick courses), you will often notice a material protruding the mortar joint; this will be the damp proof course.
- Spalled or cracked bricks and broken pointing can be another point of entry for water. Once the face of the brick is removed, water will soon work through the porous brickwork.
Condensation
Damp may not always be coming from the outside of your house. Condensation can also be another cause of damp problems, especially in rooms with little or no ventilation and a lack of heat. It is caused when warm air meets a cold surface (such as a metal window). If improving ventilation is an issue, you might need to improve the insulation and increase the heating to that room. Other than increasing the level of heat to that room, one solution is by using polystyrene-backed paper fixed with fungicidal adhesive. You can also use polystyrene lining paper. Before doing this, make sure that the surfaces are as clean as possible. If condensation is on windows, a cheap solution may well be the installation of secondary double-glazing as an intermediate solution. The preferred solution is however the replacing your widows with double-glazing.
Rising Damp
If damp is worse at the bottom of a wall than at the top, the damp proof course we mentioned earlier is probably to blame. Once you have checked that the damp proof course has not been bridged (by earth piled against the wall), and assuming it has not, your next option is replacing the whole damp proof course. This will normally be the job for the professional and, by using a contractor; you will receive a damp proof certificate, which will prove extremely useful when selling your home.
To find a company who may assist you further, simply click on the free links located on the right hand side of the page.
Comment on This Article:
All HTML, except <i>, <b>, <u> will require your comment to be moderated before it is publicly displayed.
If you would like your own avatar displayed, read about comment avatars.
Reader Comments
Skip to form
There are currently no comments about this article.