DIY Doctor UK DIY Forums

Hi, Im new to this forum. I have a problem with an existing flat roof extension. We have an extendion from our kitchen making a dining room. It was done long before we moved in, the extension is single skin, think what they did was use existing walls for outbuildings and joined them up and stuck in a patio door and then put a flat concrete roof on, the flat roof is the problem. There are no joists or anything, just a few inches thick re-enforced concrete roof with felt on top. Consequently the room is freezing and is permanently damp, the walls are ok but the ceiling is dripping with condensation and black with mould and damp. No matter how often we paint it or steet it with all sorts of anti mould treatments within weeks of painting it is black again and the paint is peeling.

So we need to insulate this roof somehow, the easiest option would be probably to add insulated plasterboard or similar to the inside, however the roof is fairly low and we dont want to lower it further even if its only a couple of inches. So this leaves us with the option of insulating the flat roof itself, This is where I need advice, im not a builder and dont have lots of cash so ideally would need a cheap and easy way to insulate the roof, any suggestions? Hopefully within the next 5 -10 years we will be demolishing this room and adding a 2 storey extension so im just after something that will last for that period of time.

Thanks in advance for any advice offered. :D

Hi There

Have you had a chance to look at the DIY Projects area yet: https://www.diydoctor.org.uk/projects.htm There are several projects relating to Insulation, Damp and flat roofing. Most of these projects have been presented by comapnies that specialise in each area so if you cannot find the answer to the question in the project then one of these companies may be able to assist you.

Regards

fix 2x1 batten to concrete ceiling and use sprayfoam insulation.
clear the felt from the roof and paint aquaseal bitumin on it.