Damp Dilemma

May 20, 2006 36 Replies

By whom? Where? Do you trust it more than similar demonstrations pointing in the other direction? Why close you mind when you don't have to?

*Seems* *fairly* conclusive. That sounds like politicians' talk. Can you have degrees of conclusivity? I'm sure the principle of dpc injection is valid for rising damp (in the odd instance where it does exist). The fact that it has been hijacked by cowboys and touted as a cure for penetrating damp is another issue.

If it does work, why is it necessary to remove all the plaster up to about

1 metre on treated walls and replace with a waterproof sand/cement mix under a final skim?

I guess because being constantly wet degrades the plaster, especially old lime stuff, and it becomes hygroscopic for some reason. In fact it's probably only the new internal render that keeps the damp at bay, and nothing to do with injection. However, that could be because it's been used to cure what I call falling damp, which is indistinguishable from the rising variety. Outside wall gets wet all the way up, weight of water takes it down inside the wall till it hits the perfectly functioning original dpc whereupon it is forced outwards on to the surface 2-3 ft above the floor. Not a widely held theory but it makes sense to me.

Lime plaster always is. That's how it works - by breathing.

It keeps the damp in the wall, certainly, but is this a good idea?

By that theory, if it can't get out it might just top up to over the waterproof part of the plaster?

The Rising Damp question from all the angles

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What did you do plaster wise?

I only drilled 10mm holes for the probes. Left the plaster and it dried out, plugged the holes.

There are folk that have stood walls of various compositions in water, with nothing rising. There are buildings standing in water, again with no rising damp. There are various discussions about the physics of what does, doesnt, can and cant happen. And the prize for rising damp that nobody managed to claim. Then there are stories such as the dpc company that injected tap water and never had any complaints, and the steady stream of reports of cases of alleged rising damp successfully treated by more realistic means.

I cant think of any, what have you in mind?

why be childish when you can just discuss the evidence?

snip waffle

NT

At what point in ownership did you do this work? Ie, can you be sure the plaster and damp wouldn't have dried out anyway?

It's just that all the pro firms always replace the plaster - regardless of its condition.

Breathing and drinking aren't the same thing. Lime in good condition isn't hygroscopic or it would never have been used externally.

I think then it's an easier route to the outside wall

>

As usual the 2 sides have a vested interest in their point of view. Building pathologist indeed!

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> swered/

Absolutely, but with so many _Experts_ how the hell is joe public expected to make a reasoned decision on this issue.

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Do your own tests. Draw your own conclusions

Unfortunately, those conclusions are going to be pretty useless when the homebuyer pack comes out and the surveyer's report says "damp".

As all usually do. Even on a property with one of these 'damp courses' recently installed.

Surveyors' reports say "damp" by default. It's just another negotiating tool for the buyer. If you know you've got damp, try and sort it out yourself and, when the time comes to sell, tell them to shove their report. If it's damp coming through the walls, paint the exterior with an oil based masonry paint. If it's coming up from ground level, check for plumbing leaks, faulty rainwater system, lower the the ground level and possibly dig a ditch and fill with gravel. If it's condensation, don't be so stingey with the heating :-)

What's your opinion then?

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