Damp patches either side of chimney breast

[IWantMyHoney]

What's causing this? The chimney? How costly is this to sort out?

It's likely water coming in either down chimney or more likely the flashing around the chimney (between chimney and roof). No idea on cost.

Does the chimney stick out in to the room or is the internal wall flat and the chimney is on the outside of the house?

We have damp patches on our chimney because the chimney is on the outside, meaning that the gutters have end caps where they meet the chimney. The gutters often get overwhelmed and overflow into the corner of the house wall/chimney breast and soak through the walls. We need new gutters to fix this, though fir now we're just cleaning them out very regularly and checking the end caps as often as we think to do it.

@HappyAsASandboy

Does the chimney stick out in to the room or is the internal wall flat and the chimney is on the outside of the house?

We have damp patches on our chimney because the chimney is on the outside, meaning that the gutters have end caps where they meet the chimney. The gutters often get overwhelmed and overflow into the corner of the house wall/chimney breast and soak through the walls. We need new gutters to fix this, though fir now we're just cleaning them out very regularly and checking the end caps as often as we think to do it.

It sticks out.

How old is the house? What’s it made of?

@FTEngineerM

How old is the house? What’s it made of?

1889 Victorian terrace brick built

Flashing and / or pointing around the chimney wall. Shouldn’t be ruinously expensive or complicated to fix.

Ok so depending on whether you can see any guttering/flashing issues as other PPs have mentioned. If not our house had the oddest problem, moisture in the air being absorbed by salts in the chimney breast, which had all been cemented up. The water had no where to go.

The fact it’s around the chimney could mean that the chimney has some sort of water proofing done and it’s spreading around that.

I don’t know if your are cemented up or if there’s free flow of air from fire place out of the house through the chimney. But we solved ours by removing cement from outside so saturated wall could dry, vent bricks added, dry as bone now. It doesn’t sound as saturated as ours if it’s just around one chimney tho

We had something similar happen on the centre of our main bedroom chimney breast. From what I can remember, the gentleman who came to look at it said there was a gap between the roof and the chimney which needed stopping up with some type of lead sheet, they they also relaid the slates afterwards.

I went onto our local FB group and typed in "chimney stack" and "chimney breast" to find the right kind of tradesman, as it's quite a specialist piece of work, I think. Look out for recommendations, and pictures.

We received 3 quotes of between £350 and £450, and went with the £350, as not only was he the cheapest, he was also the only one who took pictures of the issue, and took the time to explain to us what was wrong.

Glad we did go for the cheapest, as the 2 roofers finished the work in less than 2 hours! We've not had any issues with it since.

Need pictures, inside and out

Is this upstairs or down? it around the actual fireplace opening (ground level) or higher up? Do you have an open fire or is it blocked up?

We’ve had a similar problem (1910 semi) but our fireplace was disused and had been blocked up for years with no ventilation at the bottom. We had damp & blown plaster on the front and sides plus it was spreading across the adjoining alcove wall. There was no water source near it, no water getting in the chimney, lead flashing all checked and ok. House has both a slate and chemical dpc already.

An RICS surveyor looked at it & suggested the root cause of the damp was the fireplace being blocked up & acting like a wick sucking moisture out of the ground.

We’ve cleared it (was filled over 1m high with rubble, soot & twigs), had it all swept out and are planning to reinstate a fireplace and ensure it remains ventilated top and bottom. The fireplace floor will be dug out and relaid with a damp proof membrane prior to installation. Don’t know cost for this yet - builder coming tomorrow to quote.

We’ve also had the external brickwork and chimney stack repointed with lime plaster (£500). Hoping beyond hope that all of this will sort it.

Not saying this is your problem but might help if your situation is similar.

Also had a similar problem in an early 1900s house.

The fireplace had been removed and the external chimney stack had been removed and it had been capped off (properly). I thought it was due to a problem with the roof.

I was told it was to do with soot/salts in the chimney attracting moisture within the room and which can create damp patches on the chimney breast.

The solution was to have the wall with the chimney on replastered (I think with cement sand render but might have that wrong). I was very sceptical, but it worked.

Sounds like I had the same issue as @FTEngineerM.
It was a really odd random wet patch half way down the wall where the chimney breast was.

I had this problem in the summer. The biggest cost was for the scaffolding. It cost £1600 in total that included flashings, pointing and 4 mushroom top caps (not sure of the proper name). It solved the problem. I don't know which one solved the problem however it was cheaper to do all 3 at once rather than do one at a time due to cost of scaffolding.