www.ultimatehandyman.co.uk

Hi,

Over the last week a flat roof extension on my kitchen has been leaking. At first there was a lot of leaves and clutter blocking the exit to the down pipe so it would’ve had a lot of standing water. I cleaned everything out and gave it a chance to dry but the leak is back with the heavy rains today.

I’ve been in this house 2 years, the roof itself i believe is 9 years old. I tried contacting the previous owner for details about the installer or remaining warranty but no response yet.

To me the roof looks in very good condition aside from what look like bubbles that have opened up on the seam just above where the leak is. I can see other places where the seam looks to have been repaired with a lighter grey sealant.

So I’ve been trying to find decent roofers locally to take a look but the thought had occurred to me that maybe an attempt at a similar repair that has already been carried out in other seams might work on this one too.

Would anyone be able to recommend a sealant for this? I’ve been looking at epdm lap sealants but i don’t want to cock this up using the wrong product.

Any advice on how to remedy this would be great, thanks.

No expert, but do Not use any silicone type sealant (bathroom, kitchen or window) because EPDM is usually a Butyl rubber and is repaired much like a wheel tube or pond liner repair, kits are available see link.
Likely the grey stuff is EVERBUILD EVERFLEX 145 BUTYL RUBBER SEALANT 300ML Grey, But this does not go dry, semi setting.
Both Firestone and Rust-oleum have lap sealants, but this is for joints which are pressured together, not painted on!
https://www.rubberflatroof.co.uk/epdm-repair-kit.html

aeromech3 wrote: ↑Sun Oct 29, 2023 5:24 am No expert, but do Not use any silicone type sealant (bathroom, kitchen or window) because EPDM is usually a Butyl rubber and is repaired much like a wheel tube or pond liner repair, kits are available see link.
Likely the grey stuff is EVERBUILD EVERFLEX 145 BUTYL RUBBER SEALANT 300ML Grey, But this does not go dry, semi setting.
Both Firestone and Rust-oleum have lap sealants, but this is for joints which are pressured together, not painted on!
https://www.rubberflatroof.co.uk/epdm-repair-kit.html

Thanks for replying. So you reckon it’s something like everflex or a full on patch. I’m just wondering if a patch is a great idea when the little defects are in recessed area but then i could lap sealant the edges like your link optionally suggests as an extra measure.

The wet patch in the ceiling extends out from the window, don't you think this is unlikely to be from the drainage canal, difficult to see the position from the photo's.

aeromech3 wrote: ↑Sun Oct 29, 2023 11:14 am The wet patch in the ceiling extends out from the window, don't you think this is unlikely to be from the drainage canal, difficult to see the position from the photo's.

Yea you have a good point. I was also planning to try storm dry cream on the render and silicone the edge where it meets the windows frames. There’s a bit of damp at the bottom of the wall beside the window which makes me believe things aren’t quite watertight around the windows. Photos attached.

Likely, the edge of your roof does not have a drip channel and looks that the mortar base is very close to the bottom edge and almost level with it, no room for drips to form and drop without catching the wall finish and soaking into the render base.
Stormdry might sort it if it can be brushed between render flints.

Well we’ve sprung a second leak around the wood burner flue. I’ve decided to call in the professionals.

One without seeing the roof one has told me he’ll take a look but don’t tend to mess around with fixing flat roofs, it’s better to replace.

If it does come to that any recommendations on the best flat roof product to replace. Fibreglass / epdm / torched on stuff?