damp patches

[Anonymous]

hi
since having dpc(i know, sorry) the walls have been rendered but not plastered. in some parts damp, salty patches are appearing and mouldy patches elsewhere. i had to have them back to inject at the bottom of the stairs which they had missed but this area still smells damp. gotta ring them tomorow so any advice would be good. thanks everyone

 

[Anonymous]

How long since the dpc was injected, it sounds as though it was quite recently. It could take quite a while for the wall above the new dpc to dry out, but from what you describe there may still be sources of dampness there, Chemical dpcs certainly have a place in remedial works but there may also be condensation (evidenced by mould) and if the area is poorly ventilated,(like an understair cupboard for instance) then any drying out of the brickwork above could take even longer.
What is on the other side of the wall treated? could there be damp penetrating due to high ground levels outside or a solid floor on the other side..There is more here than necessarily meeets the eye. I am sure others will have useful ideas. keep us informed!

 

[Anonymous]

Useful ideas - chemical injection is a last resort and in some cases you may as well burn pound notes.

It's used far too often - well, it makes a heap of easy money for some.

 

[Anonymous]

I've just spent the past week on a project which was having a chemical dpc injected, and having seen how it's done, I'm not surprised it has such a terrible reputation.
I can see that it might just about work on soft brick, but on rubble stone (which this project was) you'd have as much success drilling a hole in the wall and p!ssing in it. The chemical quickly finds escape channels through the rubble core, and there is absolutely no way the stuff is going to create an impermeable layer through the whole wall.,
And at about £1 a litre, it's a rather expensive way of wasting your money.

 

[Anonymous]

In my view it's the cement render which is part of the process which may hold the damp at bay - for a while.

What price historic fabric?

 

[Anonymous]

Well, I've tried Gervase's suggestion for dampproofing my wall, and frankly I'm not impressed.

Not only is it still damp, but it now has yellow stains and doesn't smell very pleasant.

However, you can't beat empirical evidence.

 

[Anonymous]

You should have waited until the asparagus was well in season - the scent would be much more fragrant.

 

[Anonymous]

There are chemical principles to a chemical dpc, but I agree they are sometimes a last resort, the other options tend to be more expensive, Certainly the sand/cement render can do as much good, but having tried almost all the systems both chemical and otherwise I have found that the expense of putting a physical (astos) type dpc in can be prohibitive,costwise;In stonework ventilating the stone with ceramic pipes can be a very effective alternative, with or without the "chemical" aspect..
No one should just assume a chemical dpc is the only answer. Every case is a little different and one should (as Iam sure you will agree) try to examine, test and see in situ as many dpc types as possible.in stone the old protim ventilators have worked quite effectively especially in stone,random rubble and where only a small area of brickwork below a timber sole plate is available. You are so right in querying why a chemical dpc is needed, often it is not the answer, sadly until the ordinary person can have the otions explained, either through the RICS specialist team SPAB or a known disinterested conservation surveyor.the more the real information is made available, the more chance people will have to make informed decisions.All should consult the above if possible in order to know what their options are and even if a dpc is actually necessary. The older the building the more this applies,I feel.

 

[Anonymous]

Aaahaaa - as moi ol' grandad used to say: there's some as can smell it, and some as can't. An' oi ent saying as which is which.

 

[Anonymous]

It is rumoured that 'asparagus pee' (no relation to the asparagus pea) is linked to high intelligence <IMG SRC="http://www.periodproperty.co.uk/discussing/smileys/smile.gif" BORDER=0 ALT="">

Now which London gentleman's club was it which was supposed to have had a notice asking its members to please refrain from urinating in the umbrella stands when the asparagus was in season?


Scientific bit

 

[Anonymous]

Can't help you there. The only notice I remember seeing in a London gents' loo said:
"We aim to please. You aim too, please".

 

[Anonymous]

I thought *everyone's* pee smelled of tarnished silver after eating asparagus.