Cold Deck Flat Roof Ventilation

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

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

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. Hot roofs need to be ventilated and cold roofs don t but why. 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.

Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings.