Help, it's raining inside!

[FredPuli43]

It has been raining constantly for hours. Water has now started to drip through a downstairs ceiling. How does rain end up coming through a downstairs ceiling, dripping at a point a metre from the outside wall? Everything is fine upstairs..

[ummmm]

It might not be the rain. You might have a leaking pipe.

[jackthehat]

1. You have a leaking pipe and the weather outside is purely coincidental.
2. You have rainwater ingress 'somewhere' and it is travelling along the length of a pipe/wire before dripping off at the lowest point.

Either way........you have a problem! :o)

[johnny37]

I had this prob. Is there a dormer on the first floor above the leak? Mine was leaking where the slope of the main roof and the dormer roof meet. A roofer who was supposed to have chekced the roof should have put a piece of lead flashing at this point to divert any rain which did not get into the dormer gutter. Instead of running down the main roof at the side of the dormer into the gutter a ground level it was getting into the roof and running down the joist, exiting in ceiling of the room underneath. May not be your prob but I hope this maks sense.

[FredPuli43]

Thanks, johnny, there are dormer windows here. What's more, there's a similar leak in a room near where a chimney passes through the roof, where there must be flashing. Defective or absent flashing may be the answer to that, too.

[Canary42]

We have strong winds with the rain here - another factor which exposes weak or faulty flashings etc.

[The Builder]

I've seen water travel up to a metre or more from the entry point many times.
Along pipework or wiring as said above............... along a ceiling joist is favourite.

[FredPuli43]

Still puzzling that this is downstairs in this room. The bedrooms upstairs, above this room, are completely dry,including their floors. The roof stops a good distance above the upstairs rooms' floors, and there is vertical, uninterrupted wall above this room. How then is water getting in between the upstairs, bedroom, floors and the downstairs ceiling in this room? The dripping started in this room nearer the outside wall and has progressed inwards,across the room.

[johnny37]

I still think the rain is getting in somewhere around the dormer, either straight onto the downstairs ceiling or running down a joist. Is it possible to get into the eves with a torch to check next time there is a heavy rain (looks like its gonna be today!)

[boxtops]

We had a similar leak - when the builder investigated, he found that the rafters were sodden due to a loose tile - it's only when the woodwork couldn't take any more that it started dripping through the ceiling.

[FredPuli43]

Mystery solved! Why does rainwater come through a downstairs ceiling when upstairs celings are dry, so it can't be coming through the roof?

Because a bedroom washbasin upstairs feeds the same downpipe as the gutters . When the downpipe is partially blocked or is just inadequate in design, the rainwater from persistent downpours can't all drain away and backs up, filling the downpipe right up , until it emerges up through the plughole of the washbasin in the bedroom, fills the basin, the basin overflows and the water then seeps through the bedroom floor and the ceilng below.

[ummmm]

You've never noticed your basin being full for no reason?

[FredPuli43]

No,umm, it's in an unused bedroom and when I did notice it, it was either empty or only part filled. It didn't get any higher then, and as we had had a problem with it being blocked or part blocked in the past, I just tightened the taps and tried the plunger. I'd not heard of a basin filling from below before, though I appreciate that a waterspout passing over might achieve that ingress, from the change in pressure (as, supposedly, with the Marie Celeste). When I did find that it was filling inexplicably I did nonetheless, for a moment, wonder whether pressure difference was the freak cause! It eventually dawned on me what was happening.