Drying Damp Chimney Brickwork After Fixing Leak Damp can be a major issue in the home. Find answers to questions or post your own here.

[mthurman]

Hello,

Our chimney had a leak (failed flashings), leading to the chimney in our upstairs bedroom becoming very damp.

The leak is now fixed and we've hacked off the plaster, which was very damp, to help dry out the brickwork below. Once dry, we plan to re-plaster with a membrane below to prevent any salts coming back through the new plaster.

The brick has been exposed for about a month now and so the visible damp has not dried back much. I keep the window open to allow air to circulate, and have also tried heating the area up with fan heaters, which seems to reduce the damp temporarily, but then it comes back again.

I have a damp meter which gives readings on the visibly damp bricks from 0.8 to as high as 2.0. Some salting has appeared.

Does anyone have any tips for drying out damp brickwork? Or any suggestions on how long it might take to dry out? I imagine it must be quite saturated to not have dried back already.

I've attached a photo. Any help much appreciated. Thanks.

[welsh brickie]

hire a dehumidifier, for a few days that will dry it out

[mthurman]

Thanks for your response welsh brickie. I've tried an dehumidifier for over a week (an industrial one too which I hired) and it dried back a bit, but came back again after a day or so.

It makes me think the leak isn't actually fixed... probably time to get the third roofer up there! If anyone knows a really reliable roofer in the West Yorkshire area...

Or could it be the case that the brick is so saturated that it will just take a really long time to dry?

[mthurman]

Just wondering if anyone could shed any further light on this, as we still have a massive damp patch as shown in the photo.

We've now had assurances from roofers that the chimney is fixed and that there can be no water getting in anywhere.

My question is - Could this amount of damp on brickwork be caused by ventilation issues or condensation? Or is it clearly a leak? There are no vents or airbricks present.

It gets worse when it rains.

I've had two suggestions:

1) That it could be penetrating damp through the wall (which would be surprising if it's getting through a cavity and the chimney), or

2) That it's still leaking, but rather than spend more money trying to find the problem remove the chimney stack from the roof and tile over

Any ideas...??

[welsh brickie]

if you have damp that gets worse in wet weather on the breasting then its a definite leaking chimney stack, either its faulty flashing or its getting into the brickwork/chimney pot in the stack

[jamessley@gmail.com]

We're you able to ever get to the bottom of this leak? We're going through the exact same issue and it still continues despite having the flashing / lead changed by a "competant" roofer.