Cold Deck Flat Roof Ventilation

Hot roofs have the roof deck then insulation then the roofing material.

Cold deck flat roof ventilation.

Cold roofs have insulation beneath the roof deck which is beneath the roofing material. A ventilation gap usually 50mm should be. Ventilation for cold roofs. When thermal insulation is placed below the deck the ventilation must also be on the underside.

2011 code of practice for control of condensation in buildings stipulates that there should be a ventilation gap between the insulation and the bottom of the flat roof deck of at least 50mm. Cold deck flat roof the thickness of insulation required will vary depending on the material you decide to use and the manufacturer s specification. It depends on where the insulation is installed. There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation.

In a concrete deck for example this gap could be created by fixing 50x50mm timber battens at 600mm centres and attaching the insulation to underside of these battens.