Cncd 053 v1 5 7 2019 0 cold deck flat roof the thickness of insulation required will vary depending on the material you decide to use and the manufacturer s specification.
Warm flat roof cold flat roof.
You create a warm roof or a cold roof simply by applying the layers of the roof in a different order.
Flat roof ventilation allows for the circulation of air in the property particularly for warmer rooms in residential buildings.
On a flat roof this could be air in at.
What is a warm roof or a cold roof.
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.
Namely the insulation layers.
A warm roof is much more straightforward to install and provides a superior thermal performance and is therefore more costly.
A cold roof is an easy option when creating a flat roof simply placing insulating between the rafters.
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.
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 ventilation gap usually.
The breakdown warm roof vs cold roof.
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.
Inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer.
There are two types of flat roof systems warm and cold roofs which affect the positioning of the ventilation.
Cold roofing designs can be extremely tricky for existing.
Guidance advice on warm cold roofs www cncbuildingcontrol gov uk continuous 5mm gap at ridge.
Warm roof insulation ensures the entire roof structure is insulated meaning a warm deck roof is more energy efficient than a cold 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.
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.
