Damp Problems

[Jmorg]

Hi there, I have recently moved into a semi. Whilst decorating i peele

off some wallpaper (which was already peeling) in the spare bedroom an found the plaster very damp and stained underneath. I called th ex-owner of the house who said the chimney stack (which is on the sam wall as the damp) was leaking and a few years ago she go this fixed bu didnt remove the paper etc. For a few weeks we have had the paper of and it doesnt seem to be getting any worse and we've had bad rai lately. How can we tell if the problem has been fixed and ifafter th walls have dried out we can re-plaster again and sort the damage? Would the damp have stayed in the walls for so long if the wallpape was left on? Thanks

-- Jmorg

[Rick]

I would guess its not fixed, the wallpaper should not keep damp in, especially for a few years.

Rick

[Andrew Gabriel]

A common cause of damp on chimneys is lack of ventilation for the unused flues. They must be vented top and bottom. If they aren't, condensation forms in the flue and leaks through the wall. People often brick up fireplaces or cap off chimneys without making provision for ventilation.

Other details that might help pin down the problem would be the age and construction of the house, and what the distance between the damp area and the bottom of the exposed chimney stack is.

Once the cause of the damp has been fixed, IME it takes a good

3 months for a chimney to dry out.

[Phil L]

No. It takes only a few months for brickwork to dry out after water penetration has stopped. Are you sure it's actually still damp or just discoloured / damp damaged?

What is the wall like on the exterior behind the damp patch?

Is it directly underneath the chimney stack? - if it is, it's probably a loose or missing flashing, if it's a few feet away from the chimney then it's probably coming from somewhere else, maybe the exteriror needs re-pointing?

[Jmorg]

It still feels wet although even with heavy rian lately it feels muc drier than when we first peeled the wallpaper off. The exterior wal does look cracked around the chimney pot but this is what ha apparently been fixed. It is the full wall from roof to almost th floor exactly opposite where the chimney stack is

-- Jmorg

[Phil L]

Is the wet wall directly underneath the chimney stack or not? It can't be the chimney if it's on the wall opposite the chimney. ...also if it is, or was wet in the last 3 months then it's still leaking, no amount of paper or anything else will prevent this from drying if the leak had been stopped, how long have you had the property?

[Jmorg]

Sorry, i'm not explaining this very well. The chimney stack is on th

same wall as the damp, by opposite i meant they are on either side o the same wall.

The damp is directly below the chimney stack.

We have had the house for just under a month and are still in touc with the previous owners.

Sorry about the c> Jmorg wrote:

-- Jmorg

[Phil L]

Aha! I'm 90% certain that the flashings have come away from the chimney....this is a fairly simple job (providing you haver a large ladder and don't mind heights) and should take someone no longer than a couple of hours to put right. The flashings seal the gap between roof and chimney, usually made of lead but could possibly be flashband (stick on bitumen based elastoplast)....when the rain blows that way, thewater won't go onto the roof where it should go, it just runs down the wall, which explains why it's not been as wet this past month or so (the wind and the rain have to be in that direction) - if the rain is blowing against any of the 3 sides where the flashings are OK then very little moisture will ingress, when the wind changes direction however, it will drench the wall below.