FLAT ROOF INSULATION

Warm Roof versus Cold Roof Explained

Warm Roof	Cold Roof

It always used to be the case that flat roofs just consisted of a standard timber deck covered on the external surface by a waterproof material. This was the way it was always done for decades and very seldom was insulation ever a consideration.

When a cold flat roof does incorporate insulation, it is in the form of a type of mineral wool which is packed between timbers and joints usually about 50mm deep. You will also find an air gap between the insulation and the top of the roof; this gap is needed to keep air flowing and avoid warm air condensing on a cold deck. This condensation needs to be avoided as it could lead to dampness and rotting. To help with ventilation it is most important that soffit vents are correctly fitted; with these in place the risk of condensation is minimised. If you look at older flat roofs you will often see mushroom vents; these are rather unsightly and with the use of modern materials and methods are no longer needed. So we can see the importance of having good ventilation to flat roofs, but there is a down side, with the effective ventilation you will also lose heat from your building, costing you money.

This clearly shows the advantages of incorporating a warm deck system into your flat roof build/repair as all the insulation is moved above the structure eradicating the chance of condensation and negating the need for ventilation. The material we use for insulation is modern polyisocyanurate foam; this is a rigid material which incorporates a foil surface top and bottom to help improve its thermal efficiency and of course there is no limitation of what depth is used as it’s not restricted to the depth of the timber used.

Lancashire Flat Roofing have had years of experience installing warm deck flat roofs and our experience and quality of craftsmanship means that we can cost effectively convert your old, inefficient flat roof into a hard wearing, long lasting environmentally friendly roof you can trust.