There are two forms of warm deck roof.
Warm deck or cold deck flat roof.
The insulation is placed below the waterproof covering and is either mechanically fixed or bitumen bonded on to the top of the deck.
A cold deck is constructed as follows.
The layer of insulation is essentially placed outside of the roof.
Solid closed cell roof insulation such as celotex is placed on top of the roof deck rather than in between the rafters.
Converting a cold flat roof into a modern warm deck roof can be surprisingly economical.
Inverted warm deck roof.
The sandwich warm deck roof is the most common type of flat roof.
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.
A vapour barrier needs to be installed to reduce condensation in the roof structure.
Less thermally efficient than a warm roof construction cold roof construction remains the most common form of construction for existing flat roofs.
Epdm warm deck the warm deck roof design is the modern construction method for flat roofs and is preferred wherever this option is possible.
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.
The insulation material is placed immediately above the ceiling between the rafters.
Fortunately these days there is a better form of insulation available for your flat roof.
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.
This system is called warm deck insulation and eradicates the condensation and venting issues associated with the cold deck system.
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.
Flat roofs there are two common forms of construction for flat roofs.
Provided the existing roof is in a good state of repair and has a suitable structure a warm deck overlay can be applied.
Warm deck roof with this type of roof the insulation is placed above the roof deck but below the weatherproofing.
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.
There should be no insulation below the deck and no ventilation is required.
No ventilation is required for these types.
Warm deck sandwich or cold deck.
The solution warm deck insulation.
