cause of damp upstairs chimney breast

[saltfish]

Damp patches, upstairs only, appearing on chimney breast after wet and windy spells - the chimney is not sealed off and there is a gas fire which we disconnected and was not regularly used. After the problem started we had some repointing on stack, and the cement bedding where the pot sits redone.
After this work the problem came back worse - our roofer is not sure why - he thinks the flashing is ok.
I got a second opinion - a builder who thought it would be the flashing but when he got up there he couldn't see an issue with flashing - he has suggested it may be the London tudor brick failing and holding damp and is talking about rebuilding whole stack with engineering brick!
No obvious signs of damp in adjoining attic roof (breast is just to the side so not inspectable from attic)
1. Is this correct about the brick holding damp? - house is built 1980 - seems unlikely to me and more like ingress but I'm not a builder
2,. Could it be an unseen issue on roof getting under flashing? Nobody has lifted roof tiles to inspect
3. Could it be coming in through pot? But there is no sign downstairs by fireplace

Thanks for input

upstairs -it's similar all around chimney breast - nothing downstairs by fireplace

chimney before repointing and redoing cement on top

chimney after cementing top and repointing -same pot was put back after this pic was taken

 

[saltfish]

Really appreciate any advice on this as we've just redecorated and replastered and there's more money wasted....both my trades guys seem a bit stumped - brickwork doesn't look bad enough to me to warrant complete rebuild and chimney is not sealed - thankyou

 

[Laurieo]

Are there lead soakers under the flashing ?.

 

[saltfish]

I'm sorry but I'm not sure - can you tell from picture 2 ? Or would the flashing or tiles have to be lifted to check?

 

[saltfish]

Just Realised tiles are set in concrete so not lifted easily - when we bought house had L3 building survey done and they thought chimney was ok - but said ridge tiles needed redoing - could this be point of entry for water which is then finding its way down around chimney?

 

[Min]

I wonder if your problem is similar to what I've got here.
The water hadn't made its way into rooms below. Luckily I caught the symptoms before xmas - glistening wet bricks on the chimney stack in the loft, with water dripping off the corbelling, and rockwool acting as a sponge.
Two different roofers have said the flashing is ok, and pointing on chimney stack also fine. Chimney cap also fine. (Chimney still used for wood burner.)
First roofer shrugged his shoulders and said 'It shouldn't be happening'.
Second roofer said it's all down to the number of weeks we've had rain, and the bricks in the stack are just saturated, so the water has to go somewhere.
Luckily I found out in the autumn, and now have a large horticultural tray (55cm x 120cm x 5cm) under the corbelling. I've put some newspaper in it which soaks up the water and dries out if we get a few days without rain.
If we were lighting fires with an unlined flue, the warmth would be drying out the bricks.

Good luck - pain about having spent money on your redecorating.

 

[Laurieo]

I think the flashing should lift up.
Have a look on U tube about soakers and flashing around chimneys .

 

[foxhole]

If gas fire is unused it should be removed to allow ventilation.
Chimneys frequently get wet internally but ventilation dries them before it can be a problem .

 

[saltfish]

thanks all for comments - no corbelling I can see on it - its a straight up 1980 stack - gas fire is the fake trad coal type, so not blocking ventilation in any way, I think I'll go with investigating flashing and roof ridge

 

[Laurieo]

What does it look like in loft ?.

 

[ree]

saltfish,
The soaked bricks claim is not your problem, & the stack doesn't need rebuilding..
Your problem is the lead flashing - in particular, the back gutter, and maybe the one-piece side cover flashing.
If you lift all the tiles at the sides of the side of the stack, and especially the tiles above the back gutter then can you photo and post what you see.

The back gutter is not right, its wrongly made, & perhaps the bit of timber work below the back gutter lead that forms the back gutter support is not right either eg. a back gutter should be about 175 - 200mm wide, level, and self cleansing of leaves etc.

Why not go up into the loft and photo any water damage or stains on the chimney stack and surrounding trimming rafters?

 

[saltfish]

Thanks for that - it makes sense - as stated the Chimney breast is just below/to side of loft so I can’t inspect it from loft, (as it’s a long sloping roof that goes from ground floor at front to two stories at rear of property - and loft is quite high and narrow-) but there’s no sign of damp on roofing felt or timbers nearby in loft- so it makes sense that ingress is close to chimney- with these tiles set in concrete, how easy are they to lift? Do they have to be broken and reset/replaced? previously I’ve only lived in older houses with slate rooves

 

[ree]

I dont understand why you cant go into the loft and take photos? You have a large roof so you should have a large loft space with the loft chimney breast accessible from all four sides?
You could even fix a camera to a batten for taking hard to reach "selfies" so to speak?

Neither do I understand your observation that the tiles are "set in concrete"? On the majority of concrete tile roofs the tiles are simply hooked over the tile battens and can be easily lifted off.

There are no soakers when one piece side & cover flashing is used over profiled tiles.

 

[noseall]

Are there lead soakers under the flashing ?.

You don't soaker profiled tiles.

 

[noseall]

Damp patches, upstairs only, appearing on chimney breast after wet and windy spells - the chimney is not sealed off and there is a gas fire which we disconnected and was not regularly used. After the problem started we had some repointing on stack, and the cement bedding where the pot sits redone.
After this work the problem came back worse - our roofer is not sure why - he thinks the flashing is ok.
I got a second opinion - a builder who thought it would be the flashing but when he got up there he couldn't see an issue with flashing - he has suggested it may be the London tudor brick failing and holding damp and is talking about rebuilding whole stack with engineering brick!
No obvious signs of damp in adjoining attic roof (breast is just to the side so not inspectable from attic)
1. Is this correct about the brick holding damp? - house is built 1980 - seems unlikely to me and more like ingress but I'm not a builder
2,. Could it be an unseen issue on roof getting under flashing? Nobody has lifted roof tiles to inspect
3. Could it be coming in through pot? But there is no sign downstairs by fireplace

Thanks for input

View attachment 334704
upstairs -it's similar all around chimney breast - nothing downstairs by fireplace
View attachment 334707
chimney before repointing and redoing cement on top
View attachment 334708
chimney after cementing top and repointing -same pot was put back after this pic was taken

Probably a back-gutter fail. It may even be ebbing back, looking at the unfortunate coursing of the tiles. I'd lift the tiles behind the back gutter and investigate.