Flat concrete roofs

[pete37]

Hi all, for some unknown reason our house was built with a flat concrete roof on the bathroom. we have put a false ceiling in the bathroom because we don't like the look of the bare concrete,but we get really bad condensation coming through from the concrete, which then in turn comes through the false ceiling.Has anybody got any ideas on how to stop this or reduce it.....or any help at all!!!!!
I thought a divorce might help, but sadly not.......please help!

cheers Pete

 

[masona]

Check the roof is not leaking, if that's okay then it must be condensation which will need more ventilation, a auto humidity fan maybe the answer specially in the bathroom, any photo of your roof?

 

[pete37]

Hi.The roof is not leaking as it has been recently sealed on the outside.The problem has persisted even after the work has been carried out. I have no photo at the mo.A better description would be to say that half the roof is concrete and the other half is the normal apex house roof, its almost like half the bathroom was an extension, although it is part of the original build I would say the problem is definitaly condensation, and a lot of it. We do have a small extractor fan, but this does not seem to help

 

[masona]

I would say the problem is definitaly condensation, and a lot of it. We do have a small extractor fan, but this does not seem to help

The extactor fan need to be on longer or more ventilation, auto humidity fan will do it auto for you, I can't help wondering if you have a leaking roof

 

[bendylow]

concrete roofs that have become porous and then re-sealed take a long time to dry out,and the only way the moisture can go is down, i did one a few years ago and the bloke swore blind it was still leaking,i explained the problem,but he was having non of it.so in the end i hired a de-humidifier for a week and explained how it worked.AND WADDA YA KNOW,one week later,his still leaking roof had somehow managed to seal itself.(and he never even offered to pay for the de-hum).

 

[memor maplin]

Sounds like that ceiling is far to cold , all that hot humid air hitting it and becoming condensation.
An extractor fan is good for starters. Get rid of the false ceiling and insulate it. Use a vapour barrier then overboard the whole thing.

Memor