Dripping damp and stains on chimney breast.

[MartinB85]

Hi Guys,

I'm at the end of my patience with my house at the moment, we moved in 18 months ago and it's had some serious hidden gems most of which we've fixed.

The house is a 1920'S detached property with chimney breast at both sides. The side open to the elements is the one that we have tried to fix plenty of times.

We've had a brand new roof, guttering, chimney swept and work done to seal holes on the upper section of the chimney. However, we are still getting damp coming through on the chimney breast wall in patches. The main issue is at the top where the bedroom wall meets the ceiling, this morning it was actually dropping and you could see the moisture. I've gone up into the loft and there is nothing coming from the roof and no damp running down the timber.

It's not possible to see the wall off the chimney breast from the lost as the roof runs right down to the top brick.

My next step is to have Thermocrete used to fill the chimney and seal any internal cracks and holes, we would then be able to use the fireplace with coal/wood as it hasn't been used in a number of years. We have had a quote of £1500 to thermocrete the whole flue, remove the old gas fireplace so that we can just put a fire grate in.

I'm just looking for any advice on wether this would be the next best step?

Should I remove the plaster on that side of the wall and have the work re-done possible placing a membrane on the wall before hand, or is it worth leaving and waiting to see if the flue work would help.

Any advice would be extremely helpful

(The outside image is before we had the roof replaced and chimney work completed.. we also now have to chimney cowls on top)

 

[stem]

I had a very similar problem and it took me about 2 years to find it. I remember one night during heavy rain clambering about in the roof at 2am in my PJ's to see if I could find out where water was coming in, but the roof and loft were always dry. I had a cowl fitted, then the flashing replaced, all to no avail. I even resorted to having the chimney stack removed to below the roof-line and the roof tiles extended over the top, yet still the damp still remained. In the end it turned out to be water getting into the soffit further along the roof at the front of the house. The water ran inside the soffit stopping at the point where the chimney protruded into it, where it puddled and then soaked through the bricks causing the damp inside. None of this was visible outside.

This may not be your problem of course, but I mention it because l also blamed the chimney and focused all my attention on that, when actually the problem was elsewhere.

 

[MartinB85]

I had a very similar problem and it took me about 2 years to find it. I remember one night during heavy rain clambering about in the roof at 2am in my PJ's to see if I could find out where water was coming in, but the roof and loft were always dry. I had a cowl fitted, then the flashing replaced, all to no avail. I even resorted to having the chimney stack removed to below the roof-line and the roof tiles extended over the top, yet still the damp still remained. In the end it turned out to be water getting into the soffit further along the roof at the front of the house. The water ran inside the soffit stopping at the point where the chimney protruded into it, where it puddled and then soaked through the bricks causing the damp inside. None of this was visible outside.

This may not be your problem of course, but I mention it because l also blamed the chimney and focused all my attention on that, when actually the problem was elsewhere.

I'm hoping the guttering isn't the cause. When we moved into the house (after a survey had been completed and somehow they missed it) we opened up the built on cupboards and where the main stains in the pictures, the plaster had just peeled away and it was open brickwork about 2ft x 3ft at the top of the wall. So its definitely a pre-existing issue. We've had all the guttering/soffits replaced since but the main cause of the problem is still on going so my last resort is the Thermocrete which should fill in gaps in the brickwork.

It's then probably then a case of taking off the plaster at that side (only been up about 12 months!) letting it dry out for as long as possible, then maybe speak to someone who can replaster with a waterproof membrane on that side.

 

[Footsoldier888]

Have you been in the loft when it is raining? Perhaps it could be a tile problem. It doesn't take a lot of water to make these marks and it isn't always very obvious when in the loft. Maybe get a few buckets up there and see if you get anything.

Personally I would not be thinking about membranes as they are only a suppressent, I think you would be better to find the cause first.

 

[MartinB85]

Have you been in the loft when it is raining? Perhaps it could be a tile problem. It doesn't take a lot of water to make these marks and it isn't always very obvious when in the loft. Maybe get a few buckets up there and see if you get anything.

Personally I would not be thinking about membranes as they are only a suppressent, I think you would be better to find the cause first.

I popped up a few days ago when it was pelting it down, but it was dry as a bone, I moved the insulation and boarding insulation just to double check but its a fully new sealed roof and the problem was present before the roof got done a bout 4 months ago.

It's a an old house, and in the loft its difficult to see anything to do with the chimney breast just the top row of bricks before the roof hits the wall.

 

[Footsoldier888]

Sorry I somehow managed to miss that roof bit. Could it be the flashing or apron on the chimney?

 

[MartinB85]

Sorry I somehow managed to miss that roof bit. Could it be the flashing or apron on the chimney?

Flashing has been done twice, the roofers re-did it as they we're not impressed with the quality of the leading that the guttering guys previously installed for us.

I'm unsure on the apron the company who did the roof did do a full inspection of the chimney at the time and only came back with the lead been crap.

Whilst the majority of the damp is dripping from the top of the wall there are patches appearing just sporadically on the wall, which makes me think its getting in through the salt build up. The fire used to an open one I assume back in the day, there is an old back boiler present and a capped off gas fire in place... probably not been used for at least 10 years... probably longer.

 

[bobasd]

i cant make out why youve put up an old before photo? so you you still have a gas fire still in the fireplace. take it out and sweep the flue. the flue from the bedroom chimney breast above has it been swept if its open or is it blocked off??
salts from soot can pull lots of water out of the air and look like penetrating damp when its not.
youve got rafter sprockets and they could be mixed up in this leaking especialy where the roof plane changes, some roofers cant deal with this detail.
lead back gutters can give lots of leaking problems.
in the loft use a selfie stick to push dwn a camera for some snaps below the sprockets to see the eaves..
if the renders not been changed you seem to havea tyrolean coating that dont look to be in good nick.its peelin a little.

id drop the ideas about thermoconcrete and the tanking membrane. your all over the place at the momentjust stick to finding any cause .

 

[MartinB85]

i cant make out why youve put up an old before photo? so you you still have a gas fire still in the fireplace. take it out and sweep the flue. the flue from the bedroom chimney breast above has it been swept if its open or is it blocked off??
salts from soot can pull lots of water out of the air and look like penetrating damp when its not.
youve got rafter sprockets and they could be mixed up in this leaking especialy where the roof plane changes, some roofers cant deal with this detail.
lead back gutters can give lots of leaking problems.
in the loft use a selfie stick to push dwn a camera for some snaps below the sprockets to see the eaves..
if the renders not been changed you seem to havea tyrolean coating that dont look to be in good nick.its peelin a little.

id drop the ideas about thermoconcrete and the tanking membrane. your all over the place at the momentjust stick to finding any cause .

Thanks for the advice, i’ll pop up some new photos of the outside when the weathers dried up a bit.

I’ll try use a selfie stick... I attempted to reach down and take some pictures but couldn’t take see anything.

The gas fire is capped and will be removed shortly, both flues were swept just before christmas and failed due to smoke coming out of both flues when testing each one, but I expected that.

 

[michaelscad]

i.'ve done much work on older houses
many have sealed up the stacks this creates
a damp problem stacks should be able to have ventilation ifn you've sealed up the stack knock outa brick stick in a vent best todo it on both floors

 

[MartinB85]

Hi Guys,

A quick update. As the rain has been torrential for a few hours I went up into the loft and found the route cause of the issue.

As the pics show there is a significant amount of water coming in from around the chimney breast onto a joist which runs across the chimney breast, this is then dripping down into a small gap which I assume drops down onto the top of my bedroom wall.

I'm certain this is causing the main damp at the top of the wall, there are some smaller separate patches at the bottom of my wall which may be associated with it.

I've spoken with a couple of plasterers regarding the wall who have advised that I should remove the plaster on the effected wall once the issue has been fixed and allow the wall to completely dry before re-plastering.

The roof company I used have a number of credited associations linked with them including the FMB and the roof is guaranteed for 20 years, and they are coming straight out today to have a look. I've had to shove some old towels down where the gap is to soak up the dripping for the moment.

Would you expect the roof company to refund costs to cover the re-plaster?

Thanks in advance

 

[Footsoldier888]

Well it's good news you have identified the leak. However it sounds like you need some more work doing!

As for the roofing firm, it depends on what was agreed contractually. If you asked them to replace the roof and they have done so but the leak is related to the chimney, then I wouldn't have thought they would be liable. However if you asked them to fix the leak and they suggested a re-roof then that is a different situation.

 

[Nige F]

I can't see from your outside pics but you have a serious problem with the back gutter to the chimney. Maybe your roofers don't understand lead flashings

 

[MartinB85]

The roof company came round and removed the tiling. They’ve check the lead and back guttering which is completley dry as is the felt.

He took some pictures which were showing some decent breaks in the chimney pointing. He said he was just surprised that it would produce so much leakage on the outside of the chimney, so it can only be working its way in from the top and downwards and back out.

So pointing is the next call, which was supposedly fixed by our guttering company.

 

[MartinB85]

The roof company came round and removed the tiling. They’ve check the lead and back guttering which is completley dry as is the felt.

He took some pictures which were showing some decent breaks in the chimney pointing. He said he was just surprised that it would produce so much leakage on the outside of the chimney, so it can only be working its way in from the top and downwards and back out.

So pointing is the next call, which was supposedly fixed by our guttering company.

So after they left I decided to take another look, I went up and got my hand in behind the chimney best probably about tile up from the chimney itself and could see droplets under the felt. I reached in and it was sodden with black sludge. I've messaged back with pictures asking if this is normal.