Leaking roof around chimneys PHOTOS

[DizzyK]

Hello, advice needed urgently.

We moved into a house which had a damp stain on the lounge ceiling by the chimney. The surveyor said it could be a leak from the water tank, or maybe the flashing. His external roof report said it looked 'reasonable' for a asbestos-slate roof that was done in the 70s, although some were showing weathering, curling and needed repainting.

The first roofer we showed the external roof to said there was no problem with the exterior, even though we had also showed him the inside of the chimney with the water marks down the chimney wall.

The second roofer actually put up some scaffolding and said the flashing was fine (although I can see a gap?) but there were cracks in the harling (pebbledashing?) on the sides of the chimney, and that the wind would blow the rain through those cracks. As a short term measure he used a can of Thomsons water seal all over.

I live in a windy, wet exposed place, and rain is now dripping a bucket in roof again. It's also running along the beam towards the fascia and down the chimney wall to the lounge :'(

Would cracks in the harling really make water come inside? Isn't the flashing there to prevent this? The flashing has been pushed up by white stuff, I don't know if that is what is used for the harling. The two external photos are after the roofer came, after he scraped off some of the white stuff and pushed the flashing down, and after he sloshed water seal on it. You can't see the cracks in the harling very well.

This is inside of the roofspace before we bought the house, attic roof room to the right of the wall. The black is plastic covering the cladding on the water tank.

http://i176.photobucket.com/albums/w170/MCDizzyKipper/singles/DSC00378.jpg


Next two are external chimney views.
http://i176.photobucket.com/albums/w170/MCDizzyKipper/singles/DSC00491.jpg

http://i176.photobucket.com/albums/w170/MCDizzyKipper/singles/DSC00492.jpg

We don't know what to do now. Any advice much appreciated.

Thanks.

PS, it might be better to drag the photos on to your destop and view them there so you can zoom in to look at the bottom flashing, etc.

 

[masona]

The only photo you haven't got is the top chimney flashing which I don't think you're able to do regarding safety

What on the other side of the stud wall in the loft?

Where would say the wettest area is?

 

[DizzyK]

moderator I don't want them to be an issue. Curious about the bandwidth as they are hosted on Photobucket? I didn't reduce the size as I wanted to keep them as good as possible for the detail...

I can optimise them if you really need it, and/or upload to your site if you like

The other side of the studwall is a bedroom. It's definitely wettest where on the wall, where it meets the slope of the roof and runs down.
There is no felt as far as I know it is timber clad on the inside, which I believe is common here.

 

[DizzyK]

That's a good idea Thank you.

 

[mnb]

You really want to look "behind" the stack at the back gutter - 90% of chimney flashing problems are back gutter related.
However, water test (gentle hose spray) the front apron the side flashings and the back gutter in turn. Observe results inside the loft.
Only use roof a ladder and tie the access ladder in.
Is the stack necessary? It could be dropped to below roof plane and patched over.

 

[DizzyK]

Going up on a ladder isn't possible I'm afraid. The roofer didn't think there was a problem though. I think if it was back gutter it would be coming down inside the bedroom?

The stack is for a rayburn in the kitchen and an open fire in the lounge, so it's needed.

At the moment it's set to rain here for the next 5 days If we get a dry spell I will give the hose pipe a go though

What I'd really like to know it, is the harling making it waterproof? Shouldn't any water that gets behind it run down and hit the flashing and so NOT enter the roof space? Does it look to you like the flashing goes under the harling?

 

[^woody^]

Flashing is just to seal the roof/chimney junction, and water running down behind the render will go behind the flashing too

In the first image where is the location of the chimney? And does the dampness start behind the chimney, at the sides or is it just evident on rafters in front of the chimney?

Initially, I'd say that it looks like too much dampness to be getting in through just cracks (unless these are really wide. Normally rain entering such cracks would soak into the brickwork rather than run down any adjacent timber

 

[ChrisR]

Doesn't the white deposit on the slate in front of the stack make it look like water's getting behind the flashing?
And is that lead as narrow all the way up the side as it is at the front?
Any sealant?

 

[htgeng]

Doesn't the white deposit on the slate in front of the stack make it look like water's getting behind the flashing?
And is that lead as narrow all the way up the side as it is at the front?

I was going to say the point about the width of the flashing, but you beat me to it. Even if its the width of a tile, whats to stop driving rain just tracking across and going into the roof space. I would have thought some sort of upstand on the lead would be required, which is impossible with slates?

 

[^woody^]

Yes, I did not get that part of the image from the OP's links, and salts are a sign of water getting behind the lead

Its hard to make out if the lead is properly pointed into the stack, or if its just got a token lip into the render.

Also if rain is getting behind the render, then that is a problem in itself and can cause it to become hollow and detach from the stack

 

[DizzyK]

Thanks for your replies.

in the first pic the chimney is the section directly to the right of the black plastic. as you are looking at it. That is the outside face of the chimney as shown in other photos (south). The final right panel, is a bedroom wall. All 3 other chimney wall are in the room and are OK. The west side is in the cold water cupboard, the back of which when u look inside (south side) you can see insulated/covered in plastic.

The flashing as far as I know - having not seen the back side - is all the same width, that's how it appears to me on the photos? Is that not wide enough?

I don't know if there is any other sealant.

The white stuff was hard, the roofer tried scraping some off from under the flashing in order to try and sit the flashing down better. It looks the same colour as the edge od the harling, i don't know if it's the same stuff?

If the harling is detached, or has cracks, will this cause the water to run inside?

By the way houses are not made of brick in Shetland - never seen one. This house is timber framed, but I have no idea what is under the harling. Also, the rain often comes horizontally here with strong winds... can rain for days at a time without giving walla chance to dry out. The house was empty for 2 years before we bought it during last winters icy spell. It has been dry over the summer but the last few days of rain and strong SSE winds has made it leak again. Due to rain for next 5 days at least and it's not looking good for autumn/winter gales!

So how should this be done? Reharl the chimney, reflash it with wider pieces? Reroof the lot?

 

[datarebal]

To me the white staining looks like simple patina, this clearly shows to be coming from under the right hand side from under the flashing. Also to me the lead looks fairly new and the has been oiled on the top surface only (hence the patina from under)

The front apron flashing looks shoddily fitted into the chimney and the side flashing front apron lap looks a bit small for such locations.
The side flashing has some sort of upstand/turn up which you can determine by the way the slates are cocked up each side.

The roof is possibly cement fibre slate, perfect for shetland and such places

I would say get the scaffold back check all round including back gutter and head of chimney.
Strip out slates on both sides to see whats going on. replace flashings as needed.

or remove chimney fit a twin wall flue? before the rot takes hold.

 

[masona]

If it was me and the area you're living in, I would strip it down completey and re-do it correctly

http://www.leadsheetassociation.org.uk/html/1405.html

 

[DizzyK]

I think you're right. Any ideas on a rough cost for reharling the chimney and redoing the flashing? The wood inside seems sound enough.

 

[masona]

I think you're right.

Providing you're 100% confident it's leaking from flashing