Leaking Roof on Bay window

thebaldwindowfitter

were the frame meets the cill should be sealed on the ends to stop water going down the cavity.is the upstairs window wider or narrower than the bay where it meets the wall

tuggy12

a6windows wrote: »

were the frame meets the cill should be sealed on the ends to stop water going down the cavity.is the upstairs window wider or narrower than the bay where it meets the wall

Thanks, I'll have a look at the cill ends tomorrow (snow permitting).

The upstairs window is approx 6ft 6" wide brick to brick
and the bay is 8ft wide brick to brick. The upstairs window is central over the bay, so there's about 9" difference each side.

tuggy12

>>>>>>>>a6windows

Thanks for your suggestions.
Had a look at the silicone sealing around the upper window this morning and there is a continuous seal all around the frame/wall and around the ends of the cill.
The silicone seal comes down the side of the window frame/wall along the cill/wall, down the end of the cill/wall and then along under the cill/wall to to the other side of the window, where again the seal is continuous around the cill and back up the window frame.
It's really sealed as well as it could be and I can't see any way water could penetrate to the Cavity.
I think I'll have to try the bitumen paint over the lead sheet and flashing and take it from there?

thebaldwindowfitter

you are not understanding where i mean .the frame sits on the cill and it is this that needs sealing

thebaldwindowfitter

have you checked the roof above the upstairs window its possible that the water is getting in there and running off the top of window down cavity .why not try getting a piece of visqueen(polythene) which is wider than the bay lip it under the wall flashing and if you can the front edge round the bay if you cant do that weight it down with bricks.if this still leaks after you have tried this then its not the lead

tuggy12

a6windows wrote: »

you are not understanding where i mean .the frame sits on the cill and it is this that needs sealing

Thanks, I understand now, it's the gap shown in this photo below:




I'll fill that with silicone first and monitor that and then try your visqueen idea later if needed.

tuggy12

a6windows wrote: »

have you checked the roof above the upstairs window its possible that the water is getting in there and running off the top of window down cavity .why not try getting a piece of visqueen(polythene) which is wider than the bay lip it under the wall flashing and if you can the front edge round the bay if you cant do that weight it down with bricks.if this still leaks after you have tried this then its not the lead

The wall above the top window is also rendered and is in good crack free condition. All the rendered walls are painted with several coats of weathershield paint.
I'll look at this again if need be after I've done your silicone sealing and visqueen ideas.

thebaldwindowfitter

tuggy12 wrote: »

Thanks, I understand now, it's the gap shown in this photo below:




I'll fill that with silicone first and monitor that and then try your visqueen idea later if needed.

only needs sealing at the very ends and on top of the cill.if you have a problem with your roof on main house or gutter is blocked this will drop straight down the cavity

tuggy12

>>>>>>>a6windows

Had a good look this morning and you're spot on!

There are gaps through to the cavity at each end of the cill between the cill and the frame. I've closed these gaps with silicone and will now wait for the next rainfall.

Once again, many thanks for your help and I'll let you know how I get on.

spinney_3

We have had excatly the same problem with our bay in 80 yr old house, laed flat roof was fine and put silicone everywhere we could see but still it leaked. We had checked the render above the bay and we thought it was fine but as the leak persisted we had a builder friend come over and he spotted a hairline crack, 1mm max, running up render directly from the bay lead flashing. He took render off and underneath the brick/motar had a cracked at some point due to settlement. He repaired the brickwork and re-rendered - and so far so good!!! So double check the rendering if you are still getting water leaking in!