damp proofing walls

How much does damp proofing cost?

Cost of damp proofing

It’s easy to jump to the worst possible conclusion when spotting, say, tell-tale bubbles and/or peeling wallpaper, or perhaps a dank and ugly patch of mould: that your property is as damp as a ducks’ nest, that the situation is catastrophic and that remedying the problem will come at the expense of that trip of a lifetime you’ve been hankering after.
The good news, though, is that it’s rare indeed that damp is as bad as it initially seems. Of course, the wallpaper will have to be stripped and the wall most likely re-plastered. But in most cases, the masonry itself will be retrievable. It simply needs to dry out.

Three main factors are responsible for damp: condensation, rainwater and rising damp, and it’s the latter phenomenon that we’re concerned with here.
So what is it? Rising damp is the common term used for the upward movement of groundwater in the lower sections of walls by a process called capillary action. It’s characterised by a "tide mark" on affected walls, caused by salts contained in the groundwater.

When the water evaporates, the salts crystallise and can cause plaster to deteriorate. And with water continually wending its way up, the situation will perpetuate. (A side-effect of rising damp, incidentally, is that a damp wall will lose more heat.)

So how to tackle the problem? It’s most likely the case that the property already has damp proofing older houses use, for example, a layer of slate between the brickwork, while well-built modern houses include damp proofing in the form of a synthetic damp-proof course (DPC), about 15 cm above ground level, to act as a barrier through which water – in theory - cannot pass.

However, the damp-proof course can be broken or incomplete, allowing moisture to find a way in – or rather up: ‘bridging’ as it is known.

Poor drainage can also be a factor, so it’s certainly worth checking for standing water in crawlspaces and/or the basement. Another factor, meanwhile, might be any raising of the ground level next to an external wall. If air bricks are now blocked, or ground-level stands above the original damp-proof course, then moisture can find a way up.

It stands to reason that the more damp-proof course there is, the less chance there is of rising damp developing. But just a few millimetres of ‘bridging’ is sufficient to cause it.

And how is rising damp treated? That depends on its severity and each case is unique. Examples of the treatments Danford Brewer & Ives offer are:

  • Removing the surrounding soil or bridging material to be a minimum of 150mm below the existing damp-proof course
  • Injecting a chemical damp-proof course
  • Replacing any damp or rotten flooring
  • Removing and replacing any plasterwork, skirting boards, radiators etc. if necessary

One important thing to stress, though, is the competence and experience of the person(s) investigating the problem: misdiagnosis can happen – and since the wrong form of treatment could then be prescribed, the overall cost will eventually be higher.
An example: we mentioned earlier how salts form causing plaster and wallpaper to peel. This might be a feature of rising damp but other phenomena (such as heat from a fire) can also cause salts in masonry to crystallise – resulting, perhaps, in damp-proof course work that is completely unnecessary.

And the cost? A good rough guide is £60 per linear metre +vat. Therefore, an average-sized living room of 4 metres by 4 metres would cost around £270 + vat per wall. But, as mentioned, each case is unique. What we can say with a measure of confidence, though, is that most jobs will take us a couple of days.

If you have any queries – whether it’s about damp proofing or any of the other building services Danford Brewer & Ives offers, such as timber treatment, basement conversions, extensions or building maintenance – then please contact us. As ever, we’d be delighted to hear from you.


The Causes And How To Treat Condensation

Causes of Condensation and How to Treat It

Winter is here, well and truly. The Most Wonderful Time of the Year is sadly no longer, everyone seems to have a cold and those that don’t are either dieting or down the gym. It’s purgatory for all the good times we’ve been having and it’s precisely at this juncture that, if you hadn’t buried the thought beforehand, one tends to notice those little imperfections around and about the place.

I mean, look at the state of that patio for one thing. Green and yellow? Is that rust on the wheel arch of the car? And what’s that…fur, it looks like…that’s suddenly sprouted on the kitchen window? Eeeeesssh.

Well, no prizes for guessing what the cause is each and every time: water, moisture, damp, condensation. It feels like it’s here, there and everywhere right now. Best draw the curtains and light a fire, right? Right, except that even this comforting act of blocking out the cold, wet, darkness propagates what it seeks to avoid. Oh no? Well, look behind your living room curtains at the window sill the following morning. Fighting it is a pain in you know where, but it’s an ongoing battle that we must square up to.

Like most battles, it’s attritional; if we apply ourselves often then it’s possible to fight back. And think of the potential consequences of not being bothered: rot, plaster deterioration, wallpaper that bubbles and peels. Not only that, condensation can also cause bacteria to flourish – leading potentially to respiratory problems – and might even cause structural problems if, say, floor timbers are affected.

Damp is caused by rain, rising damp, and condensation. It’s the latter we’re concerned with here and there is no escaping it. Its presence is a 100 per cent certainty since the very act of breathing creates moisture. If you have a dehumidifier, you’ll see how much water can collect over, say, a 24-hour period.

Everyday actions such as cooking, bathing, washing and drying clothes also cause moisture – dampening the air until water gathers on cold surfaces such as windows, tiles, and walls. And the colder the room, the worse the problem can be. Yet simple steps can help prevent it from taking hold:

  • It might be cold outside, but that doesn’t prevent you from opening the window(s) a little to reduce moisture in a room
  • Regularly wipe down surfaces (such as window sills for example) where moisture collects
  • When cooking always use pan lids and open a window to ventilate the kitchen
  • When drying clothes, try and do it outside. But that’s hard at this time of year, so how about using a clothes horse in a room that’s cool (but not cold)? Also, set up a dehumidifier nearby.
  • Don’t dry clothes on radiators: this is one of the main causes of condensation and can cause mould growth
  • If you use a tumble dryer, and if it isn’t self-condensing, make sure it is properly vented
  • When bathing, run the cold tap before the hot; this will reduce the amount of steam produced
  • After bathing or showering, wipe down the tiles to remove the surface water. Then open the window (notice the vapour billowing out) and shut the door
  • When using extractor fans fitted in either the kitchen or bathroom, remember to close all windows and doors so they work more effectively
  • A temptation might be to switch the heating off to save money. However, heating set at a moderate temperature tends to be more cost-effective in the long run – while also helping prevent condensation, of course
  • Always keep your house ventilated, even in wintertime, and prevent the blocking of airbricks e.g. by leaves
  • Try not to place furniture against walls – particularly outside walls – as this prevents air from circulating freely thus trapping moisture

As mentioned, fighting damp is an ongoing war of attrition. Yet the enemy can be held in check with a little-concerted effort. But what if you appear to be losing the fight? That’s where we at Danford Brewer & Ives come in: if damp is taking hold then you will need a competent, experienced team to investigate; misdiagnosis does happen and the costs can be high if the wrong form of treatment is undertaken.

We have a range of standard and specialist extractors, heat recovery fans and positive pressure, condensation control units, these can be installed in properties to reduce the build-up of internal moisture. We can consider linings and the insulating of colder surfaces and sometimes suggest ways to improve heating, all of these will help stop problems with condensation.

Please contact us if you have any queries – whether it’s about condensation, damp, or any of the other building services we offer, such as timber treatment, basement conversions, extensions or building maintenance. As always, we’re more than happy to help.