Insulation on a lightweight ceiling with cold flat roof


New Member

I would like to get my top floor apartment insulated but I feel that I cannot find someone who can offer the best solution or at least a solution that would bring it to the current building regulated U-value. I would describe my ceiling as a lightweight ceiling system to which a 2.5 cm thick uninsulated plasterboard is attached to. Right above the ceiling is a cold flat metal plate roof installed and when it gets very windy the temperature in the apartment is almost the same is it is outside and that with all heatings on because the wind above the ceiling just takes away all the warmth. Most of the builders advised me to get an insulated plasterboard but would only do 50mm because of the weight and the insurance. I asked if we can add mineral wool between the ceilng joists but they dont want to do it for the same reason. The 50mm thick insulated plasterboard doesnt even bring it to the regulated U-value so at this stage I am not sure what else can be done. Are lightweight ceiling systems really unable to bear mineral wool insulation togehter with 50mm insulated plasterboard in an apartment block structures? It is hard to believe that this is so difficult to fix. Should I now replace the whole ceiling system to get my apartment properly insulated? I would be really grateful for any idea or advice on this.
Thank you


Frequent Poster
Would the insulation that can be blown onto surfaces work on your underside of roof and then you could fit a light plasterboard under it? I've no experience of this type of insulation but have seen it used for many areas where mineral wool would not be suitable. It sticks to the surface and is probably quite light in weight. I recently saw it used to insulate the inside of a metal barge that was converted into a houseboat.


OP, you need to talk to the management company first, as in the majority of apartment developments, anything beyond that skin of plasterboard is not your property.