Question for all you flat roof experts...

[paulw0t]

My dad currently has an issue with a flat roof house he owns..

Basically the roof's are solid concrete so they are quite cold, As such black mold (or something black) starts to from on the roof.

I'm informed this is due to condensation from the room, warm air hits the cold ceiling.

As such usually what we have done is batton the ceiling inside then put Kingspan then plasterboard / plaster.

This has been working fine however the house is rented and the people won't want the mess inside that this cuases.
So
we where wondering if anyone has tried doing the same thing on the outside of the roof and would it be sucessful ?

Plan would be to stick Kingspan (50mm Is this enough?) to the outside roof then overboard with OSB3 boards then use the roll out butane rubber on top of this.

What sort of level of difficulty would this be? and does it sound like it would work ?

Thanks

Paul.

 

[Zeberdee]

It may work, But I'm pretty sure you'd need 100mm Kingspan/Celotex. Dont quote me on that though.

Regarding the OSB Boarding, Once again, I think that'd be fine, However your going to have to fix them down over the insulation and into the concrete.

You may be able to get special fixings??