Talk to any building surveyor and they will tell you the same thing; dampness is one of the most common problems they get called out to investigate. Funnily enough, it can also be one of the most lucrative areas of their business and the fact that the causes are usually so black and white makes the diagnosis a doddle.
Unfortunately, for anyone who isn’t entirely clued up on the structure of houses, it can be difficult to realise just why their walls are starting to show these horrid damp stains. First and foremost, if the dampness seems to be affecting the first 1.2m of the wall, there’s every chance that this is because of rising damp and this is something that won’t be covered through this piece. For more information about this problem, take a look at this article.
Instead, we’re going to analyse the potential causes for penetrating damp. The name of this defect says everything you need to know; it describes the occasions when water penetrates the brickwork and goes straight through to the internal plaster. As explained previously, it’s usually easy to see why this is occurring as we now investigate the top few reasons behind this type of dampness.
The leaky gutter
One of the first areas you should be checking is your roofline or specifically, the gutter. If you notice a crack in your gutter, which is subsequently allowing water to escape and drip down your wall, you’ve probably found the culprit.
The damage to the guttering system will promote a lot of water, particularly during the winter months, to come into contact with the wall. Bricks and water just aren’t designed to cope with this and over time, the water will penetrate the wall and find its way to your living room, or somewhere else equally as inconvenient.
The leaky cistern
This next reason is listed practically for the same reasons. A dodgy gutter can mean that water pours down the side of the wall in rainy conditions, but a leaky cistern can constantly cause this problem.
If your toilet’s cistern is regularly overflowing, with the excess water being pumped out of that small pipe on the face of the wall, you’ll almost certainly be left with a penetrating dampness issue.
Even if the pipe is long enough to discharge the water away from the wall for the time being, what usually happens is that it will hit the ground and splash back against it. Of course, some homes are lucky and have systems which have been designed in a way to prevent this, but most of the time a leaky cistern will eventually promote damp patches.
The gale force storms
While you can do everything to maintain your property and prevent the above two issues from occurring, something that’s completely out of your control are gale force storms.
On a lot of occasions, the combination of wind and rain will absolutely drench the wall and while it will be able to initially withstand such pressures, over time the situation will worsen. This is the reason why a lot of coastal homes are not fitted with cavity wall insulation, as they are regularly susceptible to wind and rain which can penetrate the brickwork, progress to the insulation which will then carry the moisture to the internal plasterwork.
If you think that your home might be at risk in this regard, it could be advisable to purchase some water repellents for bricks. This will go a long way in preventing penetrating damp and most homeowners are comfortable in applying the pastes themselves.
The dodgy wall ties
The final reason is probably the most difficult one to spot and if you can’t see any obvious signs of water coming into regular contact with the brickwork, this could be the reason why. Unfortunately, you’ll usually require a surveyor to identify this issue, through the use of equipment such as a borescope.
The wall ties that join the inner and outer leaf of your home’s walls can sometimes become cluttered with debris – and this is quite often from way back when the property was first constructed. The design of standard wall ties means that it’s impossible for them to transport water from one leaf of the wall to the other, but if they have debris sitting on top then the moisture can make its way via that route and caused the wet plaster.