Warm Deck Roof Ventilation

Ventilation is not needed in a warm roof.

Warm deck roof ventilation.

No ventilation is required for these types of roofs. Construction studies drawing detail showing how to draw a flat roof warm deck construction detail to a scale of 1 10 with a short introduction highlighting t. 25mm at eaves on each slope and 5mm at ridge. There are two ways to insulate a roof.

A cold roof design is generally not recommended for new build roof applications due to the added requirement for roof void ventilation and the difficulties in preventing. When placed below the structural deck. Building regulations state that a ventilation gap of at least 50mm must be in place between the insulation and the underside of the flat roof deck. By majority the rule of thumb is that in a domestic house not flats approximately a third of the total thermal performance of insulation can be placed below the deck with two thirds above the deck sometimes this is called a hybrid warm roof.

No ventilation is required for these types. If ridge or eaves ventilation is not possible ventilation tiles can be used at high or low level to achieve the required airflow. The insulation is placed above the roof deck but below the weatherproof membrane. Where difficulty is experienced in achieving effective cross ventilation a warm deck roof will be required.

In flat roof construction thermal insulation can be placed above and below the structural roof deck or waterproofing layer. Warm roof ventilation specification for a simple duo pitch roof bs 5250 specifies sufficient ventilation as being. In mixed climates ventilation serves either role depending on the season. Warm deck roof a warm deck roof is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation.

For both a warm and cold flat roof a vapour control layer must be installed. Warm deck this is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation.