flat roof ventilation

twinkle · 11-12-2009, 12:43 PM

hi can anyone help i'm turning my garage into a bedroom my garage has a flat roof but is also joined to my neighbours what would be the easiest and cheapest way to ventilate the roof without putting a new roof and making sure building control pass the work

stuart45 · 11-12-2009, 04:37 PM

As you called it Building Control, is it in the UK?

twinkle · 11-13-2009, 09:34 AM

yes its in uk

stuart45 · 11-13-2009, 03:58 PM

It depends on whether the insulation is on top of the deck (warm roof) No ventilation needed, or beneath the deck (cold roof) where 25mm continuous ventilation or equivilent is required.
If you are converting a garage to a bedroom, all of the elements such as walls, roof,floor and windows will have to meet the required U values.
There is some flexibility with trade offs in the elements but you would have to get a SAP rating done with this.