Roof or window seal leak?

gort · 12 Sep 2020 at 07:43

Morning all.
Had this appear after some heavy rain.
It's a flat roof extension, is it likely to be a roof leak or a damaged window seal, or something else? It's dot dab plasterboard.
It's also part way down the left side of the window also. Can't see anything elsewhere in the room.

Ta.

a1ex2001 · 12 Sep 2020 at 08:38

Looks more like water coming in over the window than down from the roof but you’d need to look outside as well.

xb8browney · 12 Sep 2020 at 08:42

Would need to see form the outside, could be anything (soaker/flashing)

pp111 · 12 Sep 2020 at 09:15

Cement is extremely porous. Depening on the pointing it can either reject water or just soak it up like a sponge, and when it reaches a certain saturation it suddenly becomes like its not there at all... water floods through. So my guess here is that you had a the wind blowing in an unusual direction at the same time as some sustained rain or gutter leakage. Water build up in the cement then woosh. The simple answer is to paint the brickwork with a transparent sealant/waterproofer on the outside above the window. Thompsons water seal type of thing ( except you can get better ones than that ). You should leave the brickwork to dry out for at least a week without rain before treating it. One treatment can last five years. Bear in mind that is a guess based on not seeing the outside.

SoliD · 12 Sep 2020 at 11:49

pp111 said:
Cement is extremely porous. Depening on the pointing it can either reject water or just soak it up like a sponge, and when it reaches a certain saturation it suddenly becomes like its not there at all... water floods through. So my guess here is that you had a the wind blowing in an unusual direction at the same time as some sustained rain or gutter leakage. Water build up in the cement then woosh. The simple answer is to paint the brickwork with a transparent sealant/waterproofer on the outside above the window. Thompsons water seal type of thing ( except you can get better ones than that ). You should leave the brickwork to dry out for at least a week without rain before treating it. One treatment can last five years. Bear in mind that is a guess based on not seeing the outside.

This is something I had once earlier year with a strong wind and rain after it had been raining for at least a week. And have literally just water sealed it this morning.

gailjon · 13 Sep 2020 at 14:04

Do you have drainage above the lintel on the outside? Water will enter the cavity of a wall and then the drains direct it back outside before it reaches the inside of the wall. I believe they are called weep vents. If you google that term you will see what I mean.

2004typer · 15 Sep 2020 at 08:44

Is there a parapet wall to the edge of the flat roof?

If there is these are notorious for water ingress if not detailed properly.