Chimney leak repair - how we fixed it

[houseonahill]

Hey everyone, just an update on a problem that bugged us for years, which I hope might help others here.

We have a large chimney stack (the rear one in the picture - sorry for the quality, had to crop!) that was causing water to leak into the room below during heavy rain.

For YEARS we tried to solve this. Had multiple attempts with different roofers. And many quotes from guys quoting everything from £80 to £7,000 to repair it. In the end, we spent a few thousand in total and had all of these works done:

1. Fully repointed
2. Reflashed and flashing edges sealed with lead mate
3. Reflaunched
4. Clay cowls and base of pots sealed
5. Entire stack treated with storm dry cream

I was up on the scaffolding myself with the last crew insisting that the re-do some of the work because it was far from neat. It was only after I got them back a second time and they followed my instructions that the job finally seems to have worked. We've had some very heavy rain since the work was done (in spring) and no detectable ingress in the loft or room below.

A huge relief. I'm hoping this continues through the winter.

What I will say is that, because the chimneys aren't in use, and I would like the roof re-felted and re-tiled one day, I think we will eventually have this stack taken away. YES we could have just done that already but I was so determined to fix this! It seemed ridiculous to me that fixing a leaky chimney stack would be so difficult, and it became a bit of a mission.

Hopefully this story may help anyone in a similar situation - and yeah, if you have the option, just removing the stack might be the better path for you!

 

[steven lee]

Good write up. Chimney stacks are one of the worst leak sources to chase because it is rarely a single fault, it is usually the combination of porous brickwork and flashing details that you listed. One thing I have found is that creams like Stormdry only do their job when the brickwork is properly dry right through, so putting it on too soon after repointing can undo the good work. Since the pots are out of use, removing the stack is honestly the sensible long term fix.

 

[houseonahill]

creams like Stormdry only do their job when the brickwork is properly dry right through, so putting it on too soon after repointing can undo the good work.

This is a good point - luckily, the pointing was done roughly a year before the cream was applied.