Bedroom Wall - Damp smell and plaster blown near chimney

30 Jul 2012
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United Kingdom
Hi all,

Would really appreciate some direction on where to start with a problem we're having.

My daughter's bedroom always seems to have a damp smell in it. The room used to have a chimney that's closed up for a long time (there is a small vent where the fireplace used to me). You can see in the images that the ceiling has dropped slightly - the chimney stack is right behind this. Also, the internal plaster is blown where I've put the blue markers.


I've checked up in the attic and the ceiling plasterboard appears to be dry. There's no sign of any broken tiles either.

The chimney used to service two fireplaces, one in this bedroom and another fireplace in the room beneath. There are built in presses in the room downstairs and I would think there may not be any air vents here. There's a damp smell in this room also!!

We've put caps on the chimneys to stop rain getting in but the smell still prevails.

The walls are solid block and are not insulated. We've hole in the wall type air vents in all rooms - the type with humidity sensors.

Would anyone know what we could do to rectify this situation. Any advice appreciated.

Many thanks,

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Only a suggestion but for the time being why not move the child out of the bedroom - damp is such bad news for children.
Then clear out the room for a bit of remedial work - it will be dusty.

Have you been in the loft & examined the chimney breasts for water stains or damp?

Next thing I'd suggest is to open up all blocked off flues at fireplace openings and sweep the flues.
Do this in both c/breasts.

Then remove, back to brick, all the plaster on that wall - & drop the coving (the stack back gutter is probably leaking & responsible for this) & remove the skirting for the while.

The stack in the photo has failing render so does the external chimney breast below. I suspect that salts from the sooty flues might have penetrated the render - & the bedroom plaster.

The flashing on the stack needs quite a bit of work, perhaps re-newing is best. The back gutter will have to be re-built correctly.
Tiles have been replaced here & there & the remainder appear to be old & perhaps worn? Lots of care must be taken when anyone goes on the roof.

The flaunching on the concrete capping slab should be well built up to the edge of the slab - to discharge rainwater, not allowing it to pool.

Any roofer who goes up should take a video same with any work done.

When you've opened up and knocked off the plaster come back here.
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I cant decide by the pictures wether they are clay tiles on the roof or red asbestos slates!! But what ever they are they need addressing. As vinn said the lead flashing or valley on the rear of the stack is knackered! I would think that there will not be any roofing felt under the slates/tiles. You wouldn't be able to rod the chimneys because of the pots that are on there. But l would reccomend that maybe you could drop the chimney/chimneys (are both of them yours?)to below
roof level and vent them in the loft after re slating/tiling.l haven't seen a gutter run across the gable like yours before! On a well slated/tiled roof you dont put a gutter right across is obvious to me that this is not a "quick fix".You will have to drop the ceilings in the areas of the leaking roof and reinstate joists and plaster boards and re skim! I would get a reccomended roofing company in to assess the situation and give you a quote.This is not a diy job!!
Thanks Vinn & Roy for taking the time to look at this and to give me your views. It's a tricky one indeed.

With limited funds, what do you think is the most economical way of approaching it. I'm conscious that scaffolding would be needed and should only be set up once.

I think that the place to start is the flashing and the stack back gutter and getting these inspected and fixed/replaced. And get the flaunching checked as well. Is the render above the back gutter definitely gone or is it that it needs to be cleaned off and painted. If it needs to be re-rendered, then how should I go about this (bearing in mind my scaffolding comment above) - would the norm be that the roofer would subcontract someone?

I've checked the attic and all appears to be dry. The slates are clay. There was a leak there about 5 years ago and the replacing of some tiles sorted this. There is felt underneath and even though it is torn in places, there is no water getting through.

Opening up the fireplaces to clean the flues is going to be a huge job. Downstairs, there are built in presses and all of these would have to come out - they are well fixed in. I could probably make a 4x2 hole to get access to the fireplaces in both rooms and clean away any debris (twigs and the like). Maybe they could be swept from the top down?!

Roy, when you say drop the chimneys, do you mean demolishing the stack about roof level and re-tiling the void?

Vinn, if the problem is the back gutter and flashing, then would it be still necessary to remove the wall plaster? Would this not dry out. Cosmetically it looks ok.

One other question, is this a job for the summer or would roofers be willing to work on a job like this during November?

Thanks again for your help.

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The flues can be swept even with the Colt terminals in the pots.
You could open up the fireback walls of the c/breast's ie. open up at the base of the c/breast on the outside, no need to disturb the inside.
After making good you could fix an air brick vent in each flue.
You appear to have two terminals on each stack so each c/breast has two fireplaces - presumably the upper fire places could be opened up/swept from inside the house?

As my post above, the plaster needs to come off the bedroom wall - its presumably contaminated with soot chemicals that need hacking off.
The plaster to be replaced by a 3:1 mix of sand & lime.
But you could do the other stuff and then wait and see.
In the meantime you will have to thoroughly dry out the room if someones going to sleep there.

Perhaps the roofing felt is doing a Hail Mary job on any back gutter leaks?
Anyhow, do as I suggested above.
How much render you wish to replace is down to you - best practice is all such render hacked off & re-rendered - maybe the cheapest for you is to seal the cracks with polyurethane but there's nothing guaranteed about it.

The work can be done anytime allowing for rainor freezing.
Hi, resurrecting this thread. We got a photo taken of the capping. Would you think that the lines shown are cracks and would water be getting through and cause a problem in the room?

Many thanks.


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Your stack is capped with a concrete flag, and on top is sand and cement mortar flaunching.
Yes, the flaunching and the flag show cracks - water will penetrate.
However, I suspect that you have damp difficulties from a number of causes.
What's the condition of the other stack area?

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