Bay window flat roof drain leaking

1 Aug 2023
Reaction score
United Kingdom
Hi all

Currently renovating our bedroom. We have a bay window which has leaked on and off. We thought we fixed the leak by painting some of that liquid roof stuff on and repointing the stone. But there's been heavy rain and I think the internal drain is failing now. I noticed the damp again while repairing the cornice as the filler wasn't drying. I've scraped the filler out and the wooden lathe is damp/wet. This area of damp lines up with the drain for the flat roof. So that's my thinking, the drain needs fixing/replacing? But I have no idea how to go about that! Any ideas?


  • IMG_20231230_130712.jpg
    516.7 KB · Views: 36
Sponsored Links
It then comes out the side anda plastic pipe that goes into a downpipe
You've coated the surface but not sealed this to the outlet pipe. This is a common thing and difficult to do and get right

Looks like you'll need to form a new [wider] outlet in the surface and properly join and seal this to the pipe within the roof.

Google " flat roof flange " or " flat roof outlet " for the principle.
Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local