Insulating Concrete Roof in Outbuilding

[insulateconcreteroof]

Hello

I'd appreciate any suggestions - we have an outbuilding with a thick concrete roof; there's no real ventilation, and it gets incredibly hot inside on a sunny day.

Unfortunately I can't insulate it from the outside. Inside, it has very restricted headroom, and there's really only room for an inch or two of insulation.

I realise that in the circus, there's probably not a lot that can be done, but almost any reduction in temperature would be worth having. Knowing nothing about this subject, would foil backed plasterboard be any use, or should I be looking at some kind of foam-based sheeting?

thanks

[welsh brickie]

batten out the ceiling with 50mm x 25mm timber, insulate with 25mm celotex insulation, then use either t&g pine/plasterboard

[insulateconcreteroof]

Many thanks, Welsh bricky, looks like that's the way to go.

Whilst I'm here - someone suggested last night that a cheap solution would be to stick polystyrene insulation boards to the ceiling - anyone got any views on whether this option is worth exploring?

[welsh brickie]

polystyrene is a fire hazard and gives off toxic fumes if alight, so it needs to be covered, it also creates condensation. Fibreglass is a cheap option

[insulateconcreteroof]

Many thanks, I'll go with the solution you advised.