Leaking around chimney stack

[sheffbrenty]

We live in an Edwardian mid terrace and have a leak in our upper front bedroom adjacent to the chimney stack we share with our neighbours.

Despite two separate roofers replacing the lead flashing around the stack, repointing the stack fully and re-doing the channel between ours and the neighbours' tiles, it's no better.

It's seeping rather than leaking and is noticeably worse after it rains and leaves a sticky, slightly dirty residue once it dries.

The second roofer is coming back to take a look, but I'm not sure he knows exactly what the cause is.

Could this actually be due to our neighbour's roof? They say they've also got a problem on their side and are having loose tiles sorted in the coming weeks.

I wonder if there is any merit in taking off the plaster down to the brick to identify and treat the source of the leak? If so, who does this kind of thing?!

 

[Burnerman]

Depending on the width of the valley material used, it's quite possible that your neighbours problems are affecting your property.
The properties don't step down a slope, do they?
John

 

[sheffbrenty]

The houses are the same height. I think the valley strip was about 20cm wide, though I'd have to check with the roofer.

 

[ree]

OP, are you talking about a Bonding Gutter - "the channel between our's and our neighbour's tiles"? Or something else?

I dont understand where the reference to a "valley" or a "valley 20cm wide" has come from? Perhaps, i'm not reading the post correctly?

OP, do not remove any plaster - later maybe, but not now.

If you post pics it all becomes much clearer.

 

[sheffbrenty]

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• sheffbrenty
• 29 Jun 2014
• 1

Chimney stack from our side

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• sheffbrenty
• 29 Jun 2014
• 1

Neighbour's roof- fortunately not ours

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• sheffbrenty
• 29 Jun 2014
• 1

Chimney stack from our side

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• sheffbrenty
• 29 Jun 2014
• 1

This is the leak- this corresponds to the back left of the chimney stack as you see it in the photos

 

[sheffbrenty]

Sorry, I'm new to the forum and not well versed in roofing lexicon. I've attached photos as you can see. Mine is the slate roof and the neighbours' is the other one with ceramic tiles. It is indeed a bonding gutter between the two roofs.

 

[ree]

Thanks for the pics.

A Bonding Gutter cannot be seen - in pics 1 & 3 the plain tile seems to merely sit on your fibre cement slate, i dont even see any sign of pointing mortar . Who said that you have a Bonding Gutter? Maybe i cant see it?

A pic from behind the stack where the "Bonding Gutter" meets the stack back gutter would help?

In pic 1:
you have a lead valley that looks very flat. The slate corners are snapped off perhaps due to careless workmen. Fibre cement slate is very fragile.
your side of the back gutter is wrongly detailed and might be discharging water below the flashings.
presumably soakers are present below the stepped flashing - a soaker(?) has detached and dropped.

In pic 2:
the neighbour'sd valley is due for re-newal and much of his plain tile roof.
flashband repairs have been made.
the backgutter on the neighbour's side can be seen to be discharging water in a more correct way.

In pic 3:
the top right corner of the stack brickwork is missing and might be allowing water into the flues?

Roofers should give before and after pics to customers. Why not show the returning roofer what i've said and ask him/her for comments?

You will have to work with your neighbour on this - its got to be a joint effort.