A 50mm air gap must be left above the insulation and allowance for venting must be made at roof perimeters.
Flat warm roof construction uk.
This approach uses insulation with no air gap either immediately above or below the roof deck.
A vapour control layer must be used below the insulation.
This is placed over the.
This is where the roof insulation sits directly on top of the timber structure thus keeping it warm and then the roofing membrane is laid over the insulation a cold roof places the insulation between the rafters underneath the ply roof covering.
Guidance advice on warm cold roofs www cncbuildingcontrol gov uk.
A roof is primarily designed to keep out rain and snow including wind driven spray from a building.
The vapour control layer is above the decking but below the insulation.
The cheapest and simplest solution is to construct a warm roof.
However a fibreglass roof will be more durable lasting up to twenty five years with regular maintenance.
A warm flat roof or a built up roof bur is one where all the insulation is above the joists deck making them part of the warm fabric of the building.
What is a roof.
Part 4 flat roof construction.
On a basic level flat roof construction comes in the form of roofing timbers or joists as they are more commonly known or steels that are laid across two uprights walls in most cases.
The steels or rsj s rolled steel joists are often built into one or both walls to give added stability to the roof structure.
A warm flat roof is formed by placing a layer of insulation over the top of the roof structure.
It can also deny access to pests.
So what is warm flat roof construction.
Due to the insulation being over the top of the roof the timber structure beneath is warm which is why the term warm roof is formed.
This option avoids the requirement to ventilate the roof.
For flat roof construction a fibreglass roof is a more expensive option than felt.
What is warm roof construction.
This is where the insulation is typically packed between the rafters.
Steve from london flat roofing explains how warm flat roof construction works in this excellent short video.
To use epdm for a warm deck flat roof construction solid closed cell roof insulation such as kingspan or celotex should be placed on top of the roof deck rather than in between the rafters.
Flat roof u value 0 18 w m2k 2 warm deck flat roof the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications.
Inverted warm deck roof the insulation boards in an inverted warm deck are laid over the structural deck and the waterproof covering.
Warm roof construction is a roof with insulation to keep the warmth in the building.
Warm deck flat roofs can be constructed on most modern construction material types such as concrete timber and timber based sheets.
The insulation is placed below the waterproof covering and is either mechanically fixed or bitumen bonded on to the top of the deck.