Damp patches at corner of Upvc windows

[Lxondecks]

Hi all,

Both windows in our bedroom have recently developed damp patches around the bottom corners of the plaster board of both windows. The house is about 10 years old so I suspect a seal somewhere may have perished. I have checked outside and the frame and there doesn't appear to be any holes in the sealant that I can see. Could anyone offer any advice.

We do live in a town house and this is on the top floor, so it is subject to more wind and driven rain.

I have attached some photos of the inside and out.

Many thanks.

 

[crank39]

The problem is the window was never bedded on a bead of silicone when they placed the window onto the cill, water is now between the cill and window and tracks sideways till it gets to the ends and wets the plaster, when sealing you need also to form a return at each end with silicone to form a dam like a barrier to stop it getting to the ends, without taking the window out all you can really do now is remove some more plaster in the corners to expose the back of the cill and try and fill the gap between the window and the cill it sits on, probably have to get some silicone on your fingers and force it in as you'll be working blind or try expanding foam, you'll need some of this to close the hole up you've made, then plaster over or filler and sand

 

[Lxondecks]

Thanks for your reply, I will give this a try. Do you think there may have been some sealant on the cill originally but it has broken down? Not sure why it's only just started now. As nothing has been done to the windows.

 

[foxhole]

Exterior trim seems to have gaps all over allowing in the rain.?

 

[Lxondecks]

Yeah I though that, but there doesn't appear to be any sealant on that part, so surely it would have always leaked.

 

[HERTS P&D]

Could it be due to 'cold bridging?' or even rotting felt from the roof above allowing rain water into the cavity? Eaves tray would fix that situation.

Andy

 

[foxhole]

Yeah I though that, but there doesn't appear to be any sealant on that part, so surely it would have always leaked.

I may have been leaking, does not always follow that it shows internally.