Sudden damp patch

[JBean]

We have been pretty lucky so far in our Edwardian semi - very little damp, just a small amount where some lead flashing had failed on a chimney.

Then this morning we had a sudden large patch of a damp in the attic bedroom. It wasn't there Friday night, then this morning there it was. It rained heavily all night, but even so. It has got wetter during the day. And now it's raining again. I think it must be the roof.

I had alway imagined that damp formed slowly, as water gradually worked its way into plaster, and would welcome advice on whether this is in fact pretty normal, and what sort of problem might have caused it.

With thanks.

 

[Flyfisher]

Oh dear
Its suddenness and being coincident with heavy rain also makes me think of the roof (I presume that's a photo of the ceiling?), though I'd also check for a leaking pipe in the attic, if there are any in the near vicinity.

All I can really suggest for now is to try to investigate as soon as possible while things are still wet as it should make it easier to trace the problem from within the attic. Bear in mind that the actual leak might be a fair horizontal distance from the ceiling staining as the water may be running along and down the rafters rather than simply dripping from a hole in the roof.

If the leak is new then I wouldn't worry about the attic timbers because a week or two of wet timbers is unlikely to do any damage. As long as the source of the water can be quickly found and cured, the timbers should then dry out without any real harm. Unfortunately, its the decor that's more easily spoiled, but at least that's not structural.

Good luck.

 

[JBean]

Flyfisher, thanks. Yes, the white area is a sloping attic ceiling. The green wallpaper is wet too. Luckily we are planning to decorate, so aren't too worried about the decor (my teenage Goth daughter has never much cared for the parrot wallpaper she inherited!) We don' think there are any pipes in the attic, so it must be the roof. It just seems so sudden.

We will endeavour to get up through our tiny loft hatch tomorrow and see what we can see.

 

[LadyArowana]

It could be something as simple as a slipped slate. We had that on mansard roof, luckily I was able to go out on a fire escape and examine the area from a cross the lightwell, and the problem was immediately obvious as the slate was caught in the gutter. A roofer was posted out a window and told he wasn't allowed back in till it was fixed :lol:

 

[Feltwell]

Agreed, first thing to do is check for the obvious broken/slipped tile or slate. Has your roof got felt or membrane underneath the tiles / slates? Not necessarily a problem if it hasn't - that was how they were built originally - but it does act as second line of defence against water ingress.

Luckily, lath & plaster ceilings are pretty tolerant of a short term soaking, unlike plasterboard. Get it fixed and it's unlikely much damage has been done. I agree with FF, get up there inside the roof space whilst it's still raining! Only thing is of course, on a sloping section with ceiling attached, the problem part may not be visible from the inside the roof void above.

Luckily we are planning to decorate, so aren't too worried about the decor (my teenage Goth daughter has never much cared for the parrot wallpaper she inherited!)

My not quite Goth yet daughter wanted her attic bedroom painting black last year. Evil Dad said No. A small compromise was made, the small bit of wall around the dormer window is now black!

 

[JBean]

Thanks. Sadly as Feltwell suspected, the culprit part of the roof space is not visible from inside. And although we have lots of lath and lime plaster, I'm pretty sure the sloping roof is plasterboard.

Luckily I have someone coming from a roofing firm tomorrow for a different job - he's not actually a roofer, but even so I think he ought to volunteer to clamber out of the roof light and have a look.

 

[bennoa1]

Could it be a blocked gutter and the water is running over the edge into the wall? or is there a downpipe in the space that is leaking? Typically it never seems to rain when you want it to!! Hopefully a simple find and fix.

 

[JBean]

Very pleased to report that it is indeed a simple find and fix. It's a slipped slate.

How did the guy from the roofing company spot it? Walked to the other side of the street and looked up. Why didn't I think of that? :roll:

He also thinks the sloping ceiling is lath and lime plaster, so it should dry out more successfully than the plasterboard I feared it was.

And the sun is shining. So things look much brighter this morning in Bean Towers.

 

[Flyfisher]

Excellent news

 

[LadyArowana]

Very pleased to report that it is indeed a simple find and fix. It's a slipped slate.

How did the guy from the roofing company spot it? Walked to the other side of the street and looked up. Why didn't I think of that? :roll:

He also thinks the sloping ceiling is lath and lime plaster, so it should dry out more successfully than the plasterboard I feared it was.

And the sun is shining. So things look much brighter this morning in Bean Towers.

Brilliant, although I'm surprised you didn't use it as an excuse to buy a drone that you could send up for inspection, lovely new toys!

 

[Feltwell]

He also thinks the sloping ceiling is lath and lime plaster, so it should dry out more successfully than the plasterboard I feared it was.

Easy to tell. Poke it hard with your finger. If your finger disappears into something with the consistency of soggy Weetabix, it's sopping wet plasterboard. If it doesn't, it's lath & plaster. It'll dry out and just leave you with a water stain.

 

[JBean]

Feltwell, thanks. The slate has been replaced and I am pleased to report no sign of soggy weetabix when I press hard on the damp patch. It already seems to be drying out and is lovely and firm