# damp proofing an old house - which approach to use



## Petal (9 Aug 2006)

Hi guys, I'm thinking of damp-proofing an old end of terrace council house. I'm considering the following options. 

Injecting a damp course into the outside walls
Electroosmotic system (Lectros) 

Think they cost about the same to do. Has anyone got any experiences with either or anything else and can recommend same?

Many thanks.


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## Sue Ellen (9 Aug 2006)

Petal said:
			
		

> Hi guys, I'm thinking of damp-proofing an old end of terrace council house. I'm considering the following options.
> 
> *Injecting a damp course into the outside walls*
> *Electroosmotic system (Lectros)*
> ...


 
Hi Petal,

What are these exactly?


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## liteweight (9 Aug 2006)

We had our house damp proofed (20 yrs ago). At that time we had Damp Store in. It's an old red brick house and rising damp was a problem. They had to take the plaster off the walls inside to a height of 4ft., if I remember correctly, and then inject the walls with a type of liquid silicone. When it was dried out, we had the walls re-plastered. It was messy, time consuming and we had to move out while it was being done! None of the above is a reflection on Damp Store because they were excellent and still are, as far as I know.

We had to inject from the inside because of the red brick. Doing it outside, the holes couldn't really be disguised and the walls would have had a 'tide mark' all around the house.

You'll be glad to hear that it was, and still is, effective. We had no more problems with rising damp!! I haven't heard of Lectros, sorry. And Sueellen, now you at least know what one of them is!!!


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## Superman (9 Aug 2006)

Injecting a damp course into the outside walls:

Injecting a chemical into the walls that basically forms an impermeable layer (presumably a form of plastic - not too sure).


Electroosmotic system (Lectros) :

Inserting an electric wire and creating an electric charge in the walls - which repels the water ions which would cause rising damp.


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## bankrupt (9 Aug 2006)

Petal said:


> Hi guys, I'm thinking of damp-proofing an old end of terrace council house. I'm considering the following options.
> Injecting a damp course into the outside walls
> Electroosmotic system (Lectros)
> Think they cost about the same to do. Has anyone got any experiences with either or anything else and can recommend same?


 
I was considering the same for my house but did a bit of research and came to the conclusion that neither is necessary. Here's a link with some ideas (might not be applicable to your situation but food for thought nonetheless): 

[broken link removed]




> Famously, Mike Parrett of Lewisham Council in London has investigated over 5000 buildings and has never found a sign of rising damp. In every case, damp was attributable to something else. Investigative journalist Jeff Howell comments 'if you invite a damp-proofing company to inspect your home for dampness problems, you should not be surprised if they "discover" its existence. That's how they make a living'. He also identifies the meters usually used to test for dampness as inaccurate. To accurately test for moisture, you have to do a drill test but this is more time consuming and costly.


 
Also: [broken link removed]


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## Sue Ellen (10 Aug 2006)

liteweight said:


> Sueellen, now you at least know what one of them is!!!


 
Thanks for that.  Learn something new every day even at my age.


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## Petal (10 Aug 2006)

Thanks for all the info guys. I think I'll get the two damp companies out to advise. The problem is that all the walls are dry-lined (plasterboard over rock-wool), and I'd have to rip all those down to get to the inside walls, which I really do not want to do. Hence I'm asking about the outside walls. I'm not sure if they're even that damp, but the concrete floor had reasonable high moisture readings, so I assume I might need to do this. I was going to get this system called aquapol, because my dad absolutely swears by it, but it's not available over here yet, so I'm looking for alternatives...

And for the above mentioned approaches see



Bankrupt - thanks for the link - excellent source of information!


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## liteweight (10 Aug 2006)

Haven't read Bankrupt's info yet but I do know that rising damp only goes up the wall for 4ft..any higher and it might be a different problem. Check that the garden level isn't above the original damp proof course. Some people laid driveway on top of driveway thereby bridging the damp proof course!

Perhaps the problem is with the floor and the walls are ok once this is sorted.


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## Petal (10 Aug 2006)

I don't actually know if I really have a damp problem. All I know is that the house is about 60 years old and at the time of building no damp proofing would have taken place. The floor doesn't feel damp either, it just had too high readings for solid wood floor. After reading bankrupt's links I'm thinking the damp experts will definitely tell me that I do need something done to it. This is all very tricky!


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## Hen (12 Feb 2008)

your floor is probably the problem not the walls. I have just ripped up all the floors in my house and there was no damp proof under them whatsoever. Have being living there for last 17 years and would always have had assummed that the problem was with the walls.


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## mathepac (12 Feb 2008)

Petal said:


> ...I think I'll get the two damp companies out to advise...


Could I suggest that you get a chartered surveyor in to advise? No disrespect to any of the companies involved or mentioned on here, but if you want independent advise, then go to someone who is just that,  independent.


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## BillK (12 Feb 2008)

Hi petal,

I was working in construction 51 years ago and there was certainly damp proofing in those days and for many years previously. If you take a look at any Victorian buildings in your area (if there are any of course) you will almost certainly see a couple of courses of blue bricks at about ground level.

I would go along with Hen re the floor possibly being the problem and also with mathepac's suggestion re a chartered surveyor.


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## backfromoz (12 Feb 2008)

we just bought a house thats over 100 years old, the surveyor told us there was a problem with rising damp and that we needed to get a specialist damp proof company to advise.Surveyor only gave a general opinion and really sat on the fence and passed the buck  (cost a lot of money too).  I was apprehensive about getting a damp company to advise as was sure they would want to "sell" me the solution Both companies I asked for qoutes advised me that the damp was due to water ingress from cracked external rendering/guttering problem and that rising damp was only a very minor issue that didnt need treatment.They were actually very helpful. damp meter will only tell you a surface is damp not whats causing the problem.most damp companys will give you a free quotation.


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## Mr Sparkle (12 Feb 2008)

Not sure what your floor build-up is, but if there is no insulation it could be condensation causing the dampness.


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## Simeon (12 Feb 2008)

bankrupt said:


> I was considering the same for my house but did a bit of research and came to the conclusion that neither is necessary. Here's a link with some ideas (might not be applicable to your situation but food for thought nonetheless):
> 
> [broken link removed]
> 
> ...


Whilst not casting aspersions at Bankrupt's take on this, I find that Jeff Howell's article is a load of unmitigated bull. Presumably he was looking for publicity for his column/book. As a plasterer with over 35 years of experience, I've been doing damproofing and tanking for about 25 years. Now damp penetrates three ways: up, down or sideways. Downwards is generally caused by roof defects, leaking pipes, condensation (interstitial or otherwise), guttering problems etc. Lateral penetration is generally caused by retaining walls, cracked plaster/brickwork/blockwork, thickness of render, lack of waterproof chemical in the plaster etc. (Lets not go into hydraulic lime mixes - that's for another day). And finally rising damp. How else can this knowledgeable fellow from The Sunday Telegraph explain that most of the 'perceived' dampness (such as peeling paint/wallpaper, rust stains on nail tops in skirting, creepie crawlies, efflorescence, spalling of bricks/blocks etc) takes place in the bottom metre of the walls. And here I'm talking about houses that have a DPM under the floor. Why did the Victorians put rows of slate about the same height as we now put DPC. To keep the spirits in the underworld? 
 I use a dampmeter ...... tho' after years of experience anyone can have a very good shot at sizing up the situation. In all that time, I've had one callback! Which I was able to rectify in little over an hour. In olden times they used imporous stones at the bottom of walls. Aesthetics? Hardly so! 
 Finally, I'd advise the OP to get a reputable damp company to sort the problem. 25/30 years guarantee is the norm. I'm sure if there were lots of follow-up problems  the insurers would pull the plug on this very valuable service.


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## bankrupt (13 Feb 2008)

Simeon said:


> Whilst not casting aspersions at Bankrupt's take on this, I find that Jeff Howell's article is a load of unmitigated bull. Presumably he was looking for publicity for his column/book. As a plasterer with over 35 years of experience, I've been doing damproofing and tanking for about 25 years. Now damp penetrates three ways: up, down or sideways. Downwards is generally caused by roof defects, leaking pipes, condensation (interstitial or otherwise), guttering problems etc. Lateral penetration is generally caused by retaining walls, cracked plaster/brickwork/blockwork, thickness of render, lack of waterproof chemical in the plaster etc. (Lets not go into hydraulic lime mixes - that's for another day). And finally rising damp. How else can this knowledgeable fellow from The Sunday Telegraph explain that most of the 'perceived' dampness (such as peeling paint/wallpaper, rust stains on nail tops in skirting, creepie crawlies, efflorescence, spalling of bricks/blocks etc) takes place in the bottom metre of the walls. And here I'm talking about houses that have a DPM under the floor. Why did the Victorians put rows of slate about the same height as we now put DPC. To keep the spirits in the underworld?
> I use a dampmeter ...... tho' after years of experience anyone can have a very good shot at sizing up the situation. In all that time, I've had one callback! Which I was able to rectify in little over an hour. In olden times they used imporous stones at the bottom of walls. Aesthetics? Hardly so!
> Finally, I'd advise the OP to get a reputable damp company to sort the problem. 25/30 years guarantee is the norm. I'm sure if there were lots of follow-up problems  the insurers would pull the plug on this very valuable service.



What I have read leads me to think that rising damp may exist but perhaps only in a small minority of cases and very particular conditions that are not easily reproduced.  Certainly there is plenty of controversy on the subject and the existence of rising damp is not as clear cut as Simeon makes out.  I suggest you do your own research before making up your mind (or paying for an expensive and perhaps entirely unnecessary treatment).


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