Damp walls: will chimney capping fix it?

blairquik

Hi,

I live in an old tenament style building in Aberdeen which has 6 flats, 2 on each level, and I am getting damp spots on my interior walls. I have looked at the condition of the stonework and pointing on the exterior and although it's old it does look pretty sound.

Spent a long time racking my brain as to what it might be, then I noticed that all the damp spots are in line with the chimneys and where the old fireplaces would have been (these have long since been blocked off). Does it seem possible that the chimneys are letting moisture into the fabric of the building as it does seem to get worse when it rains. If so, would capping the chimneys fix this and how much do you reckon it would be? My neighbour who has lived here for a while tells me that the chimneys are not currently capped.

The building is rectangular with four walls, and a chimney stack on each wall. Two of the chimney stacks have 3 chimneys, and the other two stacks have 6 chimneys.

evilgoose

If your fireplaces have been blocked off, they should still have a vent to ventilate the chimney or you could get condensation and damp patches coming through.

Also if they havent been capped at the chimney pot end, birds can nest in the chimney, over time the nests can build up and form a "bridge" between the outter wall of the stack and the interior wall and allow moisture through.

hope that helps.

Bungarm2001

evilgoose wrote: »

If your fireplaces have been blocked off, they should still have a vent to ventilate the chimney or you could get condensation and damp patches coming through.

Also if they havent been capped at the chimney pot end, birds can nest in the chimney, over time the nests can build up and form a "bridge" between the outter wall of the stack and the interior wall and allow moisture through.

hope that helps.

Yes, I agree in my experience, it's usually the blocking off of the fire place with no adquate ventilation to the chimney breast that causes most damp problems in that area. Try having some kind of ventilation installed in the blocked off bit of the fire place. Hopefully, the chimney will be clear and a good air flow will be set up. Cost should be fairly minimal, but a messy job.

I would think about getting the chimney pots capped too, but capped in such a way that keeps moisture and birds out, but also lets damp air flow out. This could be quite costly, but maybe all of you who live in the block should chip in and pay for them all to be done at the same time? This could keep the costs down.

Are you renting the property?