No ventilation is required for these types of roofs.
Warm deck roof insulation thickness.
The waterproof layer is above the insulation and a vapour control layer is placed below the insulation.
There are two basic categories of roof design.
A flat roof where the insulation sits below the waterproof membrane and above the structural deck is a warm roof deck.
Warm deck insulation 1.
A warm roof has the insulation above the structural deck which is thus kept warm.
Warm deck the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications.
Set the quinn therm qrfr ply insulation boards onto a wide 30mm bead of vapour resistant sealant applied to the upper surface of all the joists and cross noggins.
Add to this the firring pieces for slope say 75 max.
Ventilation is required for these roofs.
Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in.
Min 125 thickness of insulation board then finish on top.
18 thickness of deck.
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.
Cold flat roofs are typically avoided as you d need to install ventilation which can prove problematic for many reasons relating to space labour costs etc.
Saint gobain insulation uk manufacture and supply glass mineral wool slabs and rolls along with rigid polyisocyanurate pir boards that can be considered suitable for a wide range of applications across flat roofs whether you re looking to insulate at joist level or above the roof deck in your flat roof construction.
The insulation can be adhered mechanically fixed or loose laid.
Cold deck this is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.
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.
The vapour control layer is above the decking but below the insulation.
They lose loads of heat and are prone to leaking causing the materials to deteriorate.
How to install insulation in a flat roof with timber deck insulated above the joists.
Warm flat roofs do not need to be ventilated as the insulation is.
