Leaking Chimney

Zardoz

Hi Everyone
I am looking for a bit of advice on fixing a leak in a chimney on my Victorian terraced house.
Its a 3 storey house built ~ 1920 .

It started leaking about 2 years ago .
I had a builder examine it about 4 months ago and it seems the lead flashing had torn and was leaving in alot of water.
He replaced the lead flashing ,replasterd the base of the chimney and repaired the damp joists and replaced about 30 Bangor blue slates .
Job done or so I though.

However to my horror I noticed after some heavy deluges in Nov it was still leaking slightly.
The builder thinks that the chimney itself is leaking (The plaster).
It does have quite a few minor cracks in it .
He proposed initially to remove the chimney but this isnt a viable option .
Plan B is to reshhet the chimney in metal and plaster over that.
However to do that I must hire new higher scaffolding .
The total cost of this work is ~2000 euro and to be honest I'm not sure whether its justified.

I was thinking about trying to seal the cracks with a siloxane sealer or sealant like Thompsons Water Seal and see if this would do the trick ,I think redoing the whole chimney is a bit excessive .

Anyone have any opinions on this or experience in the past ?

Johnnyr

I bought a bungalow two years ago which was built in 1980. When I stripped the wallpaper from the chimney-breast in the sitting room some of plaster came with it as the chimney was leaking.

The chimney capping was cracked, so I re-did the capping. Just incase that didn't solve the problem I also drylined the chimney-breast, which allowed me to decorate and put in the stove.

AckwelFoley

OP, i will bet you 20 quid and a half packet of rolos that the problem is with the chimney cap.

MisterAnarchy

snyper wrote: »

OP, i will bet you 20 quid and a half packet of rolos that the problem is with the chimney cap.

By Chimney cap do you mean the top of the chimney or all the part of the chimney that extends beyond the roof ?
In my case the chimney goes up about 10 feet past the roof,its a very tall chimney.
Here are some pictures of it .
The top of the chimney is 35 ft from ground level and I have restricted access at the side of the house to get access to it.
I have had to erect very narrow scaffolding so far to get to the base of the chimney.
I sealed some of the hairline cracks today with All Weather Sealant ,hopefully I will be able to use some Siloxane sealant on it over the next few days if I can source it in this country otherwise it will be Thompsons Water Seal.
The weather conditions arent ideal for applying it but I am under pressure as the scaffolding has to go back soon.
Hopefully that will seal the chimney up,if not I will have to be it overhauled or demolished in the summer.

AckwelFoley

Dont waste your time trying to seal that chimney, it needs to be either replastered and recapped or more likely rebuilt.

Ive taken your pic, and rather crudely marked the cap. Above the yellow line is the chimney cap, below it is called the stack. The arrow in red shows what appears to be damage to the capping as i suspected, that damage may extend further into the centre of the stack. My half pack of rolos are so far safe.

The crude drawing i made is what a capping looks like from the "birds eye view" If its cracked or damaged, its pretty much like a damaged umbrella, water will get in and fall down between the flue and the stack.

Zardoz

Thanks Snyper,I appreciate your advice,it seems very accurate.
I took another picture of the chimney showing the damaged area of the cap.
Its a very akward spot to get to ,I might try to put my camera or camcorder on a pole and get it up there later today to have a closer inspection to see the extent of the damage to the cap.
I'll post those Rolos off to you now .