Damp patch after rain (picture)

Elspeth83

Hi again, I seem to be posting loads about damp problems at the moment!

I've got what i guess is a patch of penetrating damp on the wall around a window in my hallway. It only appears a few hours after raining. We've just had our guttering replaced and I can't see any obvious cause.

I've included pictures of inside and out. I'm guessing one of those pipes might be the cause? Sorry for asking so many questions I just don't want to be ripped off again and just having some ideas of what the problems might be really helps!

MoneyMate

Perhaps it's the guttering as just been replaced and I can't see any obvious cause, and following rain seems to point this way.

Do you have photos of guttering and wall area by damp patch's outside ?

DaftyDuck

I can see a couple of obvious culprits, if you've had heavy rain, and one or two other more likely causes.

On the outside wall, there's a small hole in the render above the window, on the correct side. Unlikely, but just possible. There's also the cable entering the wall, and that looks like there's a slight defect on the wall: water can run down a cable, and penetrate in surprising quantities. For both of those, silicone mastic, applied from the outside, will work. DIY job, easy, if a little messy for a beginner. While you are at it, check the mastic round that window very carefully.

However... two more likely causes. Firstly, the radiator pipes. Right location, could be leaking. Secondly, you've a loo right above that damp patch. Check all the plumbing to the cistern, check the overflow, check the waste pipe, and look for any cracks in the porcelain. If the floor isn't tiled, can you lift a board and check those radiator pipes? Even if they themselves aren't the root cause of the leak, they may well be catching a drip from the loo cistern, and directing the water along their outsides.

It could be running down inside the render all the way from the gutter.... but I frankly doubt it.

I'd really look at the plumbing in that bathroom. Yes, it's damp when raining, but this summer that's every day, innit?

Elspeth83

Thanks.

I don't think it's the guttering as it was doing it before the new was put in.

Also I'm pretty certain it is caused by the rain. Just a few dry days and it drys off. We're having the bath removed next week (all the plumbing for the sink/toilet goes under the bath and then out through the wall) so I'll have a good look at all the pipes and the wall behind the bath then. Will also check those radiator pipes as they go under floor there.

For now I'll go up a ladder and silicone around and have a close look at where the cable enters.

Thanks for replying!

DaftyDuck

Silicone around the loo overflow and soil pipe while you are at it. BUT do it on a dry day, and test each pipe for any dampness before you do anything, as it might indicate a culprit. A sheet of loo roll is a good indicator for any remaining water.