Leak at window sill

digitig

I have a problem with a leak where a window sill is fixed into the wall. When it rains, the water soaks through the mortar that the sill is set into and runs down the inside wall. I think part of the problem might be that the sill doesn't stick out past the wall on the outside; rather, it's set in a bit so there's a bit of wall beyond the sill where water can collect. Any ideas how I might fix this?

Unfortunately, the company who fitted the window (Anglian, but when I looked at the small print it was <small local company> trading as Anglian) went bust immediately afterwards -- and before they passed on our money to the warranty protection insurance company -- so although this looks as if it's defective workmanship there doesn't seem to be anybody I can chase for it and the warranty protection certificate isn't worth the paper it's printed on.

Igol

Sounds pretty shoddy. I'm assuming its upvc, is there scope for gluing on some achitrave and sealing with silicon?

mikeopvc

could be that the installer did not damn the ends of the cill with silicone before sitting the window frame onto it.
If silicone is not applied to the cill ends then water can run off into the cavity and create all sorts of problems, mainly damp in the long term.
I hope this is not the case for your sake as it will probably mean a re-fit.

Igol offers good advice, trim & seal all around the frame with exception to the bottom where it sits on the cill,(this needs to remain open to allow water from inside the frame to drain away)
Do seal directly below the cill though.
Hopefully this should do the trick.

27col

The whole point of a cill is to throw the water clear of the brickwork. What sort of a moron would do what you have described. No wonder they went bust. Probably the best solution is to remove the window and to reset it in the correct position. Possibly you will need a new piece of cill and the end covers for it.
Don't waste your time chasing anyone, they will be long gone.