Lead Flashing Around Chimney and Damp Patches on Chimney Breast Information, help and tips on many areas of roofing including trusses, tiling, venting, insulation etc....

[anilksharma]

Hi everyone

I'd really like some advice on how to diagnose a problem.

We recently had our downstairs lounge replastered. During a period of constant rain during the summer quite a big damp patch appeared on a chimney breast and the freshly plastered ceiling of the downstairs room.

We've been trying to find out a way to establish where this water is coming from. What seems weird is that there is no evidence of damp in the upstairs room, around the chimney breast.

A few things have been suggested:

- lead flashing around the chimney may be letting water in
- our house is end of terrace, and the roof has no overhang - maybe that water is running off the roof, down the side of the house and in through some hairline cracks in the wall (there are cracks of less than 2mm in the render)

How can I go about finding the source of this problem? As I say, we see no evidence of damp upstairs.

Thanks in advance.

[aleco135]

Hello,
is the chimney open on top? are the pots still on? if they are the rain can get in that way, run don the inside of the chimney and find its way in. Otherwise it could be flashing problem or render. Hard to tell without seeing myself.
If you've removed the fires and plastered over the hole you could probably do with vents putting in top and bottom to allow air flow through the chimney. Then cap the chimney. Or you'll always have damp problems.
Hope that helps.
aleco