Weird roof leak

[aaronmaoeric]

Hi everyone,
I’ve got a leak on the ceiling of my first floor. The leak is happening right where the first-floor ceiling meets the second-floor wall—our first-floor room is actually an extension. What’s strange is that it doesn’t leak during the rain itself. It only starts leaking quite a while after it’s been raining—like after two weeks of continuous wet weather—and almost always when the rain has already stopped. The amount of water is very small too. Just wondering if any of you professionals out there might have an idea what’s going on. Thanks a lot

!

 

[Si_]

Check your seal around that window. It looks manky and I can see a hole in it. Could be water is filtering through your walls, hence the delay in it appearing.

 

[aaronmaoeric]

Hi, thanks for your prompt reply, but which hole you mentioned? I will take more window seal picture and send to you tomorrow.

 

[Si_]

This one. You can see the standing water on the window sill that can get blown in there.

 

[Harry Bloomfield]

This one. You can see the standing water on the window sill that can get blown in there.

That looks like a deliberate drainage point?

 

[aaronmaoeric]

This one. You can see the standing water on the window sill that can get blown in there.
View attachment 408080

Thanks bro. I've already applied some silicone sealant today to see if it works.

 

[^woody^]

Isn't that a missing slate and a cracked slate next to the cill?

 

[catlad]

Isn't that a missing slate and a cracked slate next to the cill?

Sure is...

 

[Si_]

That looks like a deliberate drainage point?

That bit with the yellow arrow? I thought it looks like the seal peeling back. You can see it doing the same thing further up at the inner edge, although that bit likely wouldn't cause a leak.

 

[Harry Bloomfield]

That bit with the yellow arrow? I thought it looks like the seal peeling back. You can see it doing the same thing further up at the inner edge, although that bit likely wouldn't cause a leak.

Not sure now, maybe the OP could check..?

 

[aaronmaoeric]

Isn't that a missing slate and a cracked slate next to the cill?

There is no crack

 

[^woody^]

There is no crack

That's a relief.

Just the exposed nail holes then

 

[foxhole]

Poor fit around frame lots of gaps and holed leadwork.

 

[catlad]

Looks like another classic from the loft conversion brigade!