Warm Deck Or Cold Deck Flat Roof

The solution warm deck insulation.

Warm deck or cold deck flat roof.

Flat roofs there are two common forms of construction for flat roofs. In the case of a flat roof insulation is usually either a rigid board above the deck or a mineral glass wool quilt immediately above the underdrawn ceiling depending on the type of roof design and construction. A vapour barrier needs to be installed to reduce condensation in the roof structure. Warm deck flat roof.

Types of warm deck roof. This system is called warm deck insulation and eradicates the condensation and venting issues associated with the cold deck system. The insulation material is placed immediately above the ceiling between the rafters. Provided the existing roof is in a good state of repair and has a suitable structure a warm deck overlay can be applied.

There are two forms of warm deck roof. Warm deck sandwich or cold deck. The insulation is placed below the waterproof covering and is either mechanically fixed or bitumen bonded on to the top of the deck. Solid closed cell roof insulation such as celotex is placed on top of the roof deck rather than in between the rafters.

The layer of insulation is essentially placed outside of the roof. The insulation in a warm deck roof is installed immediately below the roof membrane on top of the roof deck usually with a vapour control layer underneath the insulation. Less thermally efficient than a warm roof construction cold roof construction remains the most common form of construction for existing flat roofs. Inverted warm deck roof.

A cold deck is constructed as follows. Fortunately these days there is a better form of insulation available for your flat roof. The recognised flat roof build ups for best design practices are. Warm deck roof with this type of roof the insulation is placed above the roof deck but below the weatherproofing.

By moving the insulation to the outside of the structure the roof deck is effectively brought inside which results in a warm deck hence the name this removes the the possibility of condensation forming on the underside of the deck and eliminates damp. For most domestic purposes a warm deck flat roof is superior to a cold deck. 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. No ventilation is required for these types.

There should be no insulation below the deck and no ventilation is required. Contrasted with the cold deck roof this construction has a much lower risk of condensation as the void will be of a comparable temperature to the roof.