Water ingress on chimney in loft

[latecrum]

Hello, so we exchanged on a house a couple of months ago - an ex-rental (1907ish terrace) that is in need of a little doing up. Our survey mentioned damp registered at the top of the chimney breast in the loft, and some bad staining, that according to the surveyor was likely due to the open pot sitting on top of our chimney. Since getting the keys, it's been raining non-stop and the mortar in the loft is extremely soft, and damp to the touch. Worryingly so. It was likely left this way by the previous landlord for a long time to get to this state.

I had a roofer over, who suggested we repoint the chimney, re-do the crown, and add a cowl on top of the open pot. His visual inspection of the lead flashing (from poking his head out the Velux window in the loft) said that it was likely okay, and the survey mentioned that it's condition was fair and not likely in need of immediate attention.

The chimney was repointed yesterday, crown done, and cowl added. The guys who were sent over to the do the work, did it all on a ladder no scaffolding so didn't repoint every single section of the chimney, just the worst bits. They finished the work and suggested that actually, the lead did need doing, and also some of the ridge tiles on the roof need re-bedding as well as there are visible gaps. Not sure if we're going ahead with that yet as I wasn't expecting it.

From the images attached, do you think the work done so far is sufficient to solve this problem? And does the brickwork in the loft even look safe? I'm worried the level of damp means that it is structurally unsound, but the surveyor didn't seem too fussed in our report - just told us to address the open pot... Some of the bricks are cracked and bulging.

Any opinions would be great thanks

 

[datarebal]

Well someone's been up there with a mastic gun . Done a few half hearted squirts around the flashing.
Probably a total waste of time .
The missing pointing needs doing .
And once that's all sorted , you'll Likley still have a damp chimney .

When those houses were built the only heating would have been an open fire. So the breast would be kept dry by heat going up the chimney .

You either learn to live with it . Or , take the stack down , rebuild with a lead tray , even 2 . And live happily ever after . Conditions inside your loft area isn't unusual .

 

[latecrum]

I see, so is it worth trying to repoint the brickwork in the loft with lime mortar? Or would it just look the same again by next winter. Don't think we've got the scope for a full chimney rebuild with a lead tray, probably not for years even if we started saving now!

 

[tell80]

latecrum,
There are a number of interconnecting remedial items that are causing damp problems.

To answer your Q : yes, grind out the pointing in the loft - say, 20mm to 25mm depth, and repoint with S&L or S&C.

1. the flaunching is rubbish, & needs re-doing correctly with 4:1 S&C, chippings, and a 40mm to 50mm overhang all around the stack.
2. Given you cant afford to rebuild the stack then the top 4 or 5 courses of the stack need rebuilding, & the whole stack needs repointing.
3. The metal flue terminal (typically used with a SS liner) will degrade in a few years.
4. The stack lead flashing is wrong - slates need soakers and stepped cover flashing. Moisture could be creeping on the slates under the flashing to penetrate the roof. We cant see the far side of the stack where there is a narrow gap between the stack a& the roof join?
5. The roof join has been made with mortar only - in time it will begin to crack & leak.
6. Do you have an active solid fuel fire or a burner below?
7. arrange to have your flue or flues swept.
8. Is there any damp showing in lower rooms?
9. Are any fireplaces blocked off?

 

[Exedon]

Whoever did that flashing hadn't a clue, step and cover on slates? Maybe not its to be hoped soakers are still in place .
If that gas flue liner is not in use get rid of terminal.
I've just rebuild my stacks take down to roof level
Rebuilt including air bricks new flashing.
See pics for how flashing should look.Todays job clean down before scaffold dropped tomorrow.

 

[tell80]

Exedon,

You show two different stacks - neither stack has been taken "down to roof level"?
Your pic shows four pots with what on top? Flaps of lead?
You also show three air bricks for, presumably, venting four flues?
Why have 4 x pots & 3 x a/b's attempting to vent the same flues?
No flaunching or flaunching projections can be seen?
Lead aprons are typically done in two parts: the apron itself with a 150mm upstand, & cover flashing from above covering the upstand.
Doing the lead apron in one single length would have been fine, and would be allowed.

 

[datarebal]

No reason not to use a cover flashing with soakers on slate .
In fact we are currently re skating a Saxon church in wiltshire , cover flashing , no soakers .
On the picture with a scaf tube in it looks like you need to buy a new dresser ..

 

[tell80]

Post #7,
"No reason ... slate." I dont understand: Its not usually an option but a necessity to use soakers & stepped cover flashing where slate meets sloping abutments?
If you are referring to the apron - why would soakers be needed there?

"cover flashing" as in the pic of a one piece apron, is obviously used, esp. with heavy lead codes but the traditional way is as I said.

FWIW: the pic neglects to use clips on the apron.

 

[Nige F]

Post #7,
"No reason ... slate." I dont understand:

No need to understand - the saddle is under the ridge tile too

 

[Nige F]

Exedon,

Your pic shows four pots with what on top? Flaps of lead?


No flaunching or flaunching projections can be seen?

No flaunching - that's the camera angle . 2 courses of dark (engineering?) bricks protruding some 50mm over the stack presumably the flaunching goes up to the edge of the bricks . Put your apron on and get back to your pot washing, and keep off the poteen. You know it's full moon ?

 

[catlad]

Looks like the same chimney to me! As for the chimney being brought down to roof level depends how big it was originally? It could have done with a few straps on the apron. I bet it looks a dam site better than it did before.

 

[datarebal]

Tea break ,

Same stack obviously

 

[RandomGrinch]

Perhaps Tell can't conceive that a stack doesn't have to be symmetrical over a ridge?

...but one of the ridge tiles has seemed to move between pics! - possibly waiting to be cut to fit?

Edit: actually Exedon did say "stacks" - so yes, all this hoohaa is for nothing!

 

[RandomGrinch]

But you just saying that means nothing - prove its the same stack, please give me details?

Isn't a fundamental principle of justice, the presumption of innocence unless and until proven guilty? - as you have accused a poster of lying, I'm afraid the burden of proof is on you!

 

[kp00110]

definitely the same stack