I've now had a couple of builders suggest to me the idea of an 'ambient' roof system for a flat roof, where you ventilate on the warm side. The idea apparently is that you have your insulation tight underneath the deck, then a gap underneath that, then plasterboard ceiling. This cavity above the plasterboard is then ventilated to the outside.
I can't really get my head around this: why would you ventilate the warm side, isn't that just going to lose heat? I'm also struggling to find any resources or building guidance that suggests this as an option. Everything just talks about either warm or cold roofs.
From what I can work out, I think my builder likes this solution because it takes up less height than a warm roof, but doesn't require as much ventilation as a cold roof.
Has anyone else come across this and does it work?
I can't really get my head around this: why would you ventilate the warm side, isn't that just going to lose heat? I'm also struggling to find any resources or building guidance that suggests this as an option. Everything just talks about either warm or cold roofs.
From what I can work out, I think my builder likes this solution because it takes up less height than a warm roof, but doesn't require as much ventilation as a cold roof.
Has anyone else come across this and does it work?