Leak in second (top) floor ceiling

Hi,

I have a wet area on the ceiling of the master bedroom in my semi d house. It is on the attached side of the house about 6 inches out from the chimney breast. I went up to the attic for a look, but couldn't see anything. I pulled up all of the insulation in the area and it is bone dry up there. I first noticed it last week, but it dried up, but is back again tonight. Has anyone any idea of what might be causing this?

Thanks.

How do you know it is damp and not a shadow.
or old stain comming through the emulsion paint

If ceiling board is foil-backed then it could be a condensation spot
unless there is a joint exactly where the apparent damp is.

Put pin through ceiling in centre of apparent spot and put large tray
or inverted dustbin lid in attic space over same.

you do not mention rain

theplumber said:

How do you know it is damp and not a shadow.
or old stain comming through the emulsion paint

If ceiling board is foil-backed then it could be a condensation spot
unless there is a joint exactly where the apparent damp is.

Put pin through ceiling in centre of apparent spot and put large tray
or inverted dustbin lid in attic space over same.

you do not mention rain

Click to expand...

Thanks for the reply theplumber

It is actually wet, I have touched it, and it dried up and is now wet again. Yes the ceiling is foil backed. It sounds like it may be condensation alright. I am wondering if lighting the fire is causing condensation as it is so close to the chimney block. It has been very cold over the last week or so, so maybe the warm chimney block is causing the condensation?

It hasn't really rained in the last week, so I doubt it's that.

Yes if it is foil backed board and no joint at leak then it would appear to be condensation warm moist air current rising and condensing where it changes directrion. this will occur where there is a gap in the insulation above. so make sure to reinstate insulation carefuly. Wear mask.

Possibly Damp chimney breast if rarely used. Perhaps test fire ope. for down draught. also Depends on fuel used

Occasional use of fire may always be difficult if blockwork is cold although this should not be in semi d if both houses have heat.

A hanging news paper or tissue paper will indicate direction of an air current if held against fire ope. Not with fire lighting of course I have to say that.