Warm Flat Roof Cold Flat Roof

The requirement for roof void ventilation in cold roofing designs means it is generally not recommended as a design for new build flat roofs.

Warm flat roof cold flat roof.

What is flat roof ventilation. 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. The breakdown warm roof vs cold roof. Cold roofing designs can be extremely tricky for existing.

The recognised flat roof build ups for best design practices are. Namely the insulation layers. This means that the insulation should be highly resistant to water absorption for example an extruded polystyrene based product which will not be affected by water or repeated freeze thaw cycles. A cold flat roof insulation requires more work taking off old boards and replacing them and the roof surface.

Cold roof construction requires that a suitable ventilated air space exists above the insulation layer within which the air is constantly mobile being replenished by fresh incoming air whilst the air resident within the void space is being expelled via a natural vent action at another point. Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings. Inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer. Guidance advice on warm cold roofs www cncbuildingcontrol gov uk continuous 5mm gap at ridge.

A cold roof is an easy option when creating a flat roof simply placing insulating between the rafters. What is a warm roof or a cold roof. A cold roof is best when you re initially creating a flat roof and is cheaper than a warm roof but does provide an inferior thermal performance. Warm roof insulation ensures the entire roof structure is insulated meaning a warm deck roof is more energy efficient than a cold roof.

On a flat roof this could be air in at. A warm roof is much more straightforward to install and provides a superior thermal performance and is therefore more costly. A ventilation gap usually. There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation.