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.
Warm or cold deck roof.
There are typically two different ways to insulate a roof a warm roof and a cold roof.
Warm deck flat roof.
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.
Warm roof insulation ensures the entire roof structure is insulated meaning a warm deck roof is more energy efficient than a cold roof.
This cold deck construction is considered problematic in the humid temperate climate of the uk where the effective ventilation of restricted roof voids may be impractical particularly in sheltered built up areas.
The breakdown warm roof vs cold roof.
Fortunately these days there is a better form of insulation available for your flat roof.
The solution warm deck insulation.
A warm roof building will make the entire structure of the building warm in an attempt to avoid any cold bridging.
Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.
With an older cold deck flat roof vapour control is achieved by ensuring a gap of 25mm or more between the ceiling and the insulation layer and between the insulation layer and the deck above.
Ventilation is required for these roofs.
The cold deck method works well when constructed correctly and in correct.
A cold flat roof insulation requires more work taking off old boards and replacing them and the roof surface.
In building construction roof pitch is a numerical measure of the steepness of a roof.
It is universally recommended that cold deck flat roof construction should be avoided.
Pencast cold roof construction pencast warm roof construction it is perhaps surprising and certainly unfortunate that some building professionals and contractors are under a misapprehension as to the precise requirements in order to achieve warm roof and or cold roof construction.
Namely the insulation layers.
Introduction warm cold roofs this guidance offers guidance on the difference benefits between warm and cold roofs.
The thermal efficiency isn t as good as with warm roof.
In a cold roof the insulation is applied between the rafters but in a warm roof the insulation is applied on top of the existing roof surface.
Guidance advice on.
What is a warm roof or a cold roof.
These gaps help warm moist air escape before condensing on the cold deck above.
You create a warm roof or a cold roof simply by applying the layers of the roof in a different order.