Warm Flat Roof Insulation Thickness

This is placed over the roof joists and a board normally external ply is laid on top.

Warm flat roof insulation thickness.

A cold roof has the insulation placed below the structural deck which thus remains cold. Inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation. Ventilation is required for these roofs.

There are two basic categories of roof design. 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. It should be of the maximum available thickness. The insulation material for a warm flat roof should.

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. The insulation for a warm roof will usually be boards of extruded polystyrene or rigid compressed boards of glass fibre or rock fibre. Thickness varies according to the manufacturer s specifications. Although i m sure this can differ considerably depending on insulation etc can anyone tell me what the approximate thickness of a warm deck flat roof will be including joists.

Insulation in a warm 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. The typical u value of an existing uninsulated flat roof is 1 5w m2k. With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same.

Flat roof insulation thickness. A warm roof has the insulation above the structural deck which is thus kept warm. 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. 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.

These are can be supplied with rebated edges which interlock reducing the risk of uplift. The chosen insulation laid on top of this should be able to take the weight of anything put above it on the roof without compression or protected from compression by further sheeting.