Damp patches above chimney breast

Longsmiths

Hello, we bought an old house (1840) in May 2017. The previous owner refurbished the house just before we bought it. He replaced three open fires on the ground floor, 1 with a log burning stove, 2 with gas fires. About a year after we moved in, damp patches have started appearing internally on the chimney breasts. They are a lot more visible on the first floor than the ground floor. The refurbishment included the roof and chimney pots. I'm wondering if the new sealed units at the ground floor have stopped the air circulating within the chimneys which is now causing these damp patches. What are my options for resolving these issues?

shaun_from_Africa

I can see it being one of two things.
The flashing at the base of the chimney stack could be damaged and allowing water ingress. If this is the case it's normally fairly easy to spot if you have access into your roof space as the part of the chimney in the attic will be visibly damp.

The other possibility is water getting into the chimney stack from a loose or damaged cowl.

I had a chimney cowl replaced a few years ago and the old one was cemented into place. To remove this took a lot of hammering and this dislodged part of the seal at the base of the stack which caused the problem that yo now appear to have.

FreeBear

shaun_from_Africa wrote: »

The other possibility is water getting into the chimney stack from a loose or damaged cowl.

Yet another possibility...
An 1840 property is likely to have fire places in the rooms upstairs - Assuming the fire places have been blocked off, are they vented, and are the pots externally capped ?

grumbler

Longsmiths wrote: »

...He replaced three open fires on the ground floor, 1 with a log burning stove, 2 with gas fires. ... I'm wondering if the new sealed units at the ground floor have stopped the air circulating within the chimneys...

I think neither is "sealed".