Cold Deck Flat Roof Ventilation

There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation.

Cold deck flat roof ventilation.

This video shows the key features of a flat roof cold deck construction and how to draw the details to a scale of 1 10. Ventilation for cold roofs. Cold deck flat roof the thickness of insulation required will vary depending on the material you decide to use and the manufacturer s specification. Hot roofs need to be ventilated and cold roofs don t but why.

Hot roofs have the roof deck then insulation then the roofing material. Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings. 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. 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.

When thermal insulation is placed below the deck the ventilation must also be on the underside.