Cold Deck Flat Roof Ventilation

When thermal insulation is placed below the deck the ventilation must.

Cold deck flat roof ventilation.

The minimum requirements for cold roof ventilation are set out in bs 5250 control of condensation in buildings which takes into consideration span pitch and roof area. What is flat roof ventilation. There must be an adequate void minimum 50mm between the deck and the insulation traditionally mineral wool to allow free movement of air and to prevent moisture vapour being transmitted from the building outwards where it could condensate in the roof. Guidance advice on warm cold.

Ventilation is required for these roofs. When placed below the structural deck. No insulation is on top. Ventilation is required to the underside of the deck.

In a cold roof construction the sarnafil membrane is installed directly to the structural decking usually timber with firrings to fall. Introduction warm cold roofs this guidance offers guidance on the difference benefits between warm and cold roofs. Warm deck the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications. A cold roof is where all of the insulation is placed either between and under or completely under the joists or deck.

Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings. Cold deck this is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof. Ventilation is required for these roofs. Ventilation is not needed in a warm roof.

You only need ventilation in a cold roof. In this way the roof itself is kept cold. A cold roof is the most common type of roof construction often taking the form of an uninhabited storage space.