How long should a damp wall take to dry?

dander

I have a wall with a small damp problem. It's from the floor up to about 60cm above ground and seems to be coming from within the wall - getting salt deposits and plaster blowing. It's quite a small area and exactly where the rainwater drain came down from the roof and entered the ground. My best guess is that the damp is something to do with that and thanks to some building work, this is now an inside wall and the rainwater goes somewhere else. I've been hoping that this will solve the damp problem and the area did seem to be drying out, but i noticed yesterday that the dampness seemed to have increased slightly again.

My question is - is it possible that this is normal and it will take a long while for all the damp to work its way out of the brick wall (solid, not cavity) or is this a sign that the problem is not sorted and I need to be looking for another cause of the problem?

muckybutt

sounds to me like the damp course has failed and you are getting rising damp, we have the same problem in a few areas in our old house, im looking at getting the damp proofing cream rather than injection method, every now and then we put a dehumidifier on that help draw any excess water out.

littlesnuggy

If you haven't replasted the internal wall, then there may be hygroscopic salts in the plaster which are attracting moisture to the wall.

dander

Thanks for the replies, but the real question is how long it would take to see the wall drying out once the problem is fixed.

I haven't replastered yet, because I don't want to do any replastering if I'm not sure that the problem is definitely sorted - and I certainly don't want to inject a chemical damp-proof course if I don't need it because I've heard a lot of bad things about them making problems worse rather than better!

muckybutt

Try drying it with a dehumidifier from a hire shop !

AdrianW2

dander wrote: »

Thanks for the replies, but the real question is how long it would take to see the wall drying out once the problem is fixed.

The surveyor who did our house reckoned it would take "a season".

dampdaveski

Hi dander,
The 'rule' is approx an inch a month for a wall to dry out, this is the generic rule we use after a damp proof course is installed, though there are many factors that can affect this.
As someone has stated it sounds like your plaster is contaminated with hygroscopic salts, this means that the salts in your 'damp' wall can absorb moisture from the air (ie condensation) and make the 'damp' look worse.
Does the damp patch grow during and after rainfall? If so then it sounds very likely that the wall is affected by 'salts'.
the only long term solution for this is to strip the affected area and replaster using a cement based renovation plaster or a sand/cement render incorporating a 'waterproofer' additive.
Hope this helps

Adaline

I have a similar probloem, and was told it can take up to six months if it's gone up the wall by a couple of feet. You need to make sure that the right type of plaster is put on after the damp-proof course, which wasn't done by the previous people in my hosue which is why I now have the problem.

dander

Thanks all, I definitely won't panic too soon then. I only had the downpipe moved a few weeks ago so seeing as it's a 9" thick solid brick wall, it looks like I've got a lot of drying time to go yet. I'll just let it have a good sit and dry out and start tackling the plaster in the spring.

loulou41

The surveyor picked some damp on the wall in the dining area. I had a builder who did some work for me and rectified the problem that caused the damp. He told me not to rush to fix the damp yet and wait at least till spring to see whether there has been an improvment. He said he will take some time for the wall to dry and to just monitor it. Hope this helps.