Leaking chimney, but where is the water getting in? (see pics)

[js.b1]

#1 Examine how the roofing felt turns up under the lead, because as posted I believe you may have a problem there.

#2 Repoint the chimney, SBR in the mortar where necessary.

Absolutely do not dry-line or the moisture behind will produce a string of problems with floorboards, joists, track through any party wall nearby - trying to hide the problem is a recipe for a total disaster that should be obvious and worries me that they should suggest it. Makes me want to examine that roof more closely.

BTW, you can get wireless and wired cameras quite cheaply - it could be useful to stick one in an appropriate position. From the suggest of

*wet plaster* in moderate rain I really do wonder about that flat roof re funneling water.

[george [dicegeorge]]

stick the camera up there an hour after it's rained - are there still puddles?

Better tie a ladder up there and go up in various weathers, pour buckets of water on it etc.

Maybe squeeze some thickish plastic under the flat roof around the chimney so that water flows away from the chimney.

[g]

[Tim Watts]

I was about to suggest something similar: wait for a dry day and take a hose up there. Working from the least likely to the most likely culprit areas, pour loads of water from an un-nozzeled hose with an observer inside to look for any evidence.

If that doesn't yield anything (it might not) - OP could be looking at a combination of wind and rain blowing the water back under something, in which case repeat the excercise with a spray gun on the hose.

[Phil L]

upon closer inspection of your pictures, iut seems to me that the water isn't coming down the inside of the chimney but down the outside. Am I correct in assuming the walls have been dot&dabbed? - these wet patches look like DL adhesive to me, and if they are, then the water is coming down the face of the brickwork that they are stuck to (which it must have been doing BEFORE it was covered up! *) and the water is going through the adhesive and into the plasterboard.

*Which begs the question, why did anyone cover up an obviously wet wall?

[The Natural Philosopher]

AHA! that explains the round patches. They are the dabs!

And coming down the outside is exactly what the balance of us here reckon: The flashing is crap.

But I don't reckon given the dry spring, the wall would have been wet. Not till the latest downpours.

[Phil L]

Yep, without doubt the flashing's are s**te - on one side it doesn't even reach the roof - it stops about an inch short

[Jim K]

mmm if there's so much water coming down the outer surface of the chimney breast to soak thru pb dabs placed here and there - shurely there'd be some other evidence of *lots* of water getting in - in the room below the loft conversion perchance?

OP - can you orientate us and tell us (somehow) where the c breast is relative to the stack in the pics? i.e. specifically what part of the chimney stack is directly above the damp area? are the damp spots in pic all there are in loft? or are there more? any signs in lower rooms (yet)??

Jim K

[Calum]

Yes, the walls have been dot & dabbed. The wall may not have looked wet before. Work began in the winter when we had lots of snow, and ice and things were actually quite dry.

[Phil L]

The flashing's failed, it needs replacing and *not* patching up.

Personally, if it were mine, I would want something other than lead as I don't think it's suitable in this application.

[The Natural Philosopher]

Oh its suitable, but its not a complete answer.

[Calum]

Thanks for all the answers so far. I'm going to try and work out where the problem lies scientifically i.e. with a hose and a lot of time. I need to let it dry out again first...

I'll report back my findings!

Calum

[Jim K]

dehumidifier will dry it quickest...

BTW did you see my post in this thread "8th June 15:25"? Cheers Jim K

[Weatherlawyer]

You are an idiot.

There is nothing going down the chimney from above the lead.

Look under the lead. It isn't doing anything. Get a picture of the roof when it is raining. It will be a puddle deeper than the bottom of the lead. So what he has there is a big shallow pool draining into the fireplace.

[Jim K]

and just how the F do you know that then einstein?

which picture shows what's under the lead?

I think you're the presumptive idiot here.....

Jim K

[Weatherlawyer]

Presumptive? No. Aggressive yes and an idiot at times. When he posts the pool picture you will see the bloody obvious, though how you missed the bloody obvious about the chimney not leaking above the lead I can not hope to guess.

[Jim K]

you mean we have to wait and see if your presumptions are correct?

Stiill at least you accept there's no evidence yet of what you think is wrong, that's a step forward, but still a long way to go tho ;>)

Cheers Jim K

[The Natural Philosopher]

The first time I swa that flashing I thought 'thats simply wrong'

Flashing is done the way its done because that way works.

It hasn't been done that way, ergo it probably wont work.

It doesn't take much brain to look at a car with square wheels and say 'that wont drive very well'

But I expect you would want scientific tests to back that up, as well.

[stuart noble]

What's strange in all this is that the original roofer apparently can't figure it out.

[The Natural Philosopher]

that's probably because he isn't. A roofer.

Hes a purveyor of loft conversions.

[Jim K]

from the evidence provided (to all) the flashing is at least 2 brick courses high - say minumum 4inch?

How should the flashing appear in the photographs to be "correct" in your humble opinion?

FACT we don't know what's under the flashing. Until it's inspected by someone we never will - simple irrefutable fact no?

The usual "doom & gloom", "pull it down", "start again", "you've been ripped off" theories are being vigorously promoted (by the usual suspects) solely on the basis of their imaginations and alleged expertise yet they *do not know* what is actually going on becasue

*they have not seen*.

All you are doing is betting.

Cheers Jim K