It is estimated that up to 60 percent of homeowners face a problem with damp in the basement at point in their lives. The pernicious problem has many potential causes, and therefore has a wide range of solutions too. The solution to the problem obviously depends on the cause, so your first task is to find the source of the damp. Your first port of call will be to walk around the outside of the house, looking for patches of damp, moss or mildew – anything that could indicate that moisture is pooling next to the wall, or perhaps finding its way into the wall due to cracks or some other kind of weakness.
If you find structural damage this will need to be repaired; usually by a professional, who can ensure that the wall is made watertight once more. If the brickwork looks good from the outside, you can head inside, and down to the basement. Occasionally, if the damage is small and does not affect loading bearing sections of wall, you can make DIY repairs using commercially available cement mixes. Be sure to choose one that will strengthen when exposed to moisture, rather than weaken, as this will ensure that the fix stays strong and stops any dampness oozing through the wall.
Once inside the basement, check over the walls to see if you have missed any cracks that might have been caused and hidden by creeping plants such as ivy. Another weak point is often around window frames. If these warp or shift, they can begin to let moisture into the basement. This type of leak is common especially when the window is set beneath ground level and therefore very close to the water table. A quick and easy fix for this type of problem is to fix a plastic window cover that still allows some natural light in, but is completely waterproof and reasonably cheap.
Damp is sometimes caused by the walls being too porous and allowing damp to seep through. If this is the problem in your basement you will see either large patches of damp 'flowering' on the wall or a 'rising tide' of damp creeping up the wall. It is possible to repair this problem from the outside, but it can be a very expensive and time-consuming proposition, involving losing the use of your yard for some time, while the work is done. A cheaper and quicker option is to spray the inside with a commercial preparation, easily obtainable from hardware stores, that will form a watertight layer on the inside of the room. This may not be effective if you have a severe damp problem, but should be fine for light or residual damp.
If you cannot find any direct source of moisture in the basement, it is possible that the air in the basement is full of moisture. This is very easily sorted, by installing a dehumidifier or heater to circulate and dry out the air. If you plan on remodelling your basement, try to get the damp problem sorted before the contractors come in – the smell of mould and mildew can cling for years and can even over-ride the normally pungent and pervasive smell of wet paint! If the new work is done in a dry basement, the odds are good that the materials used will stay dry and not get clammy or smelly – a boon if you plan on using the basement as a rumpus room or similar.
If your basement is little more than a crawl space the odds are very good that it does not have a proper floor laid down. (Basement finishing is not a high priority for such places, where people are not expected to spend much time!) You can try foundation repair in such a space, by laying a proper, damp proof floor, or you can abandon the idea of sealing the ground, opting for a raised 'deck' type floor instead. This will not create a pleasant room, and groundwater will ooze up through the earth, but you should be able to create a storage space. Old pallets make a perfect floor covering as they are several inches high, and can support a fair weight. As long as you wrap the goods to be stored in thick plastic, it should last quite well.
- Basements are useful spaces, for storage, keeping food and drink cool and as games or utility rooms.
- A good condition basement can add to the value of your home
- Make sure you know why the basement is damp, before trying any repairs – if damage is not repaired the problem will continue.