Rising damp does not exist

Yup - this is deliberately provocative.

Does anyone out there have any real-life examples of rising damp caused ONLY by a failed DPC in the wall? If so, please can you help me understand how it happens/happened?

I don't want to mislead anyone, so I'll state my basic postulate:

Rising damp does not exist unless there's a moisture path between one or more of the following:

- floor and inside wall
- plaster and inside wall
- render and outside wall

Any takers?

Certainly a common problem that occurs in rubble built stone houses is rising damp. Effectively there is no damp proof course existing and with modern methods of installing new concrete floors incorporating damp proof membranes moisture is forced towards the walls and rises, whereas in bygone days they would have had compacted earth or flags which did not trap in the moisture. Rising damp is however something of a falacy in general and is blamed for a plethero of ills with much abandon.

Hi legs-akimbo

Your view seems to match mine, although my experiences don't include rubble-built stone walls.

Thanks for the input.

Anyone else? Surely someone out there must believe that they've seen rising damp in a brick wall?

Rising damp is definately a real phenomena. I think that the reasons for it's occurance are often misinterpretted. I suspect that the "failure" of DPCs is, more often than not, a case where they never worked in the first place.

In Victorian days the "good old craftsmen", were quite happy to leave out DPCs where they couldn't be bothered with the faffing around to put them in. Even when my father was on the tools (in the 60s) he recounted occaisions where a joint was raked out and pointed up with tar, just to give the appearance of a properly fitted DPC.

In the well ventilated environment of the finished home, it didn't become apparent. It's only when the house gets hermatically sealed with modern windows and doors, that you suddenly notice that the walls are getting wet.

Where a DPC has actually been put in, it's "failure" is very rare. Even when the wall is subject to considerable subsidence, most of the resulting damp is more likely coming through the wall rather than up it.

There's also the issue that we are, on the whole, getting softer as the generations pass. Whereas Victorians regarded anything above 40F as lovely and warm, and didn't give a tinkers for a bit of dampness, modern western people consider anything below 60F cold, and the slightest bit of humidity is unacceptable.

I hear what you're saying TM, and I bow to your wider general knowledge on the subject, but, and I have to press you on this point, do you have a real-life example of rising damp caused ONLY by a failed DPC in the wall?

I'm talking about one that you've seen with your own eyes, and diagnosed with your own head, and fixed with your own hands and tools, and witnessed the effective cure afterwards?

I'm not asking for the address of the property, just, well, um, well, dangnabbit I suppose I am, but full technical details would suffice I'm sure

Softus said:

I hear what you're saying TM, and I bow to your wider general knowledge on the subject, but, and I have to press you on this point, do you have a real-life example of rising damp caused ONLY by a failed DPC in the wall?

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Not a "failed" one, but I sorted out a problem with a Victorian terraced house that had a serious absence of dpc. in a party wall. This wall was literally dripping wet upto about two and a half feet above ground level, and this was in the middle of a fairly dry summer. Although my client had just bought the property, his neighbour assured us that, the "tide line" rose to about five feet, during the winter. Although the retrospective fitting of a dpc was a big job, the neighbour contributed to the cost.

The original reason for my client seeking assistance was the condition of his floor. During one of his visits to the property, as he stepped in through the front door, it had literally just crumbled beneath his feet, resulting in a strained groin Oh, and while I was there, could I just give the party wall a skim to hide all the mould?

This was one of those jobs where things just went from bad to worse. Besides the damp, the ground floor turned out to be riddled with wood worm. All in all, I got quite a lot of business from this job but, the client made a massive profit when he sold up a couple of years later (with no sign of damp, anywhere in the house).

His neighbour was also astounded at the difference it made to his house. Although he had installed double glazing a couple of years previous, he had been disappointed with the results. The damp had just got worse, if anything, and the house was still rather cold. Once the DPC had been sorted it completely changed the feel of the whole house and was much cheaper to warm through. His family's health had also improved, with their constant suffering of colds and flu like symptoms finally dissipating.

Although this was quite a bad case of rising damp, it was caused by the complete asbsence of a dpc. (not the failure of an existing one). I daresay in other areas, even it's absence wouldn't have been noticable. It all depends on the local geology of your environment and prevailing weather conditions.

In the same area I have seen damp patches caused by dodgy conversions. Typically a length of wall that has been knocked through with no DPC used in the making good. Where the DPC has been left out of about a foot of wall, the damp patch of a about a square foot will result.

So far, (apart from vehicle impact sites), I have yet to see a properly installed DPC actually "fail". I have even witnessed houses that have suffered from serious subsidence, with no sign of rising damp. Penetrating damp is far more common.

I have also seen a "rising damp" issue, as diagnosed by a surveyor. Upon looking outside, I noticed that the client had built a raised flower bed up against the wall. The external wall of the house (which was of a solid construction) formed the back of this flower bed with no protection whatsoever. The surveyors confusion is understandable as he hadn't ventured into the garden, and the clients hadn't thought to mention it.

I'm not asking for the address of the property, just, well, um, well, dangnabbit Been watching the re-runs of Deputy Dawg, have we?.Bless AAMOF I recall the phrase was DAG nabbit. You see, despite my present mental condition. I have a very clear recollection of events in the past

OK TM, if you'll permit me to carry on playing devil's advocate, the Victorian house had a damp problem.

I hope I'm safe in assuming that the problem arose sometime after the house was built, i.e. that it was dry and habitable until something happened to make it damp.

If so (emphasis on the "if"), then do you know what happened to cause the problem? Was the party wall original, or had something been built onto, or up to, the wall on the other side. I'm very intrigued by this.

Also, I haven't quite understood what you did to remedy the problem - I dare say that this is the clue to understanding what the fault was

Cheers
S.

PS Where are all the other stories of rising damp from the rest of you out there?

Nige F said:

...dangnabbit... Been watching the re-runs of Deputy Dawg, have we?.Bless AAMOF I recall the phrase was DAG nabbit. You see, despite my present mental condition. I have a very clear recollection of events in the past

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Quite right - dagnabbit, so it was. And I never knew until now!

may i just tag somic about DPC's in stone houses. We lived in a flat (council flat) and one day they turned up drilled hundreds of holes slopping down into the front of the building, seemed to pump something into the holes and left them open to the rain for three years. They only got blocked up when the painted the outside of the building. Now this building was built in 1750 out of great big lumps of local granite. Did it need a DPC? my opinion is that they did more damage than 200+years of damp in three years of "care".

from my days as a surveyor, extremly rare in its true form. for a dpc to fail it needs mechanical damage or incorrect fitting in the first place. If it does fail then any damage is limited to a small area. As i said in another post most damp is caused by another fault eg blocked downpipe, bridging etc.
As for fitting a dpc to an old stone building that was built 300 years ago, no it probably didnt need it as it was designed to take account of the damp. Just seems to be a modern fixation/trend cure all. Still could coat it all with pva i suppose(quick duck!)

drilling a hole into granite, and trying to inject sealer..... well i wouldnt expect it to work in anyway.

sidecar_jon said:

...one day they turned up drilled hundreds of holes slopping down into the front of the building, seemed to pump something into the holes and left them open to the rain for three years.

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... I'm afraid that's because they were prats, sj.

sidecar_jon said:

drilling a hole into granite, and trying to inject sealer..... well i wouldnt expect it to work in anyway.

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I'm no builder but have witnessed a little test which we found surprising at the time. Not sealer, but I have witnessed engineering measuring 'plates' of high quality granite ... absorbing almost as much water as could be chucked at it ... Well ok, plasticine circular dams filled 10 or 12 mm deep, dry after several hours, similarly dammed / depth of water on metal plate resting on granite - no change.
If water 'soaks in', is there not every chance of it moving up through the fine 'pores' in a capillary action if the base of the material is partially immersed ?
I once lived in an area plagued with 'springs' appearing in cellars without warning .. not mine thankfully, but what effect would running (replenishing) water have at foundation level in the event of none or damaged DPC?
EP

It seems to me that rising damp is far worse in some areas than others. If you've seen it you can't mistake it. My house was absolutely dripping in condensation from damp and all the floor joists were rotten. The wallpaper hung off the walls in strips and the plaster disintegrated.

When the DPC was injected you could see droplets of water forming on the bricks like sweat on a brow and actually trickling down.

Withing days of the completion of the DPC the problem was solved. The house is dry as a bone.

It amazes me that people deny the occurance of rising damp just because they haven't seen it. I've never seen a wild Giant Panda or Orangutang - but I don't doubt their existance.


joe