Inverted Warm Roof Construction

Warm inverted roof inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer.

Inverted warm roof construction.

Insulation boards are loose laid on top of the membrane and then weighted down with paving slabs or gravel ballast. No vapour control layer is required. Inverted roofs are designed with the waterproofing layer usually a liquid applied membrane beneath the insulation. No vapour control layer is required.

An inverted roof construction sees the principal thermal insulation layer located above the roof structure and also above the waterproofing this method results in the waterproofing the structural deck and the support structure all being at a temperature similar to that of the interior of the building. An inverted roof also referred to as a protected membrane or upside down roof is form of flat roof in which the waterproofing layer is beneath the thermal insulation rather than above it. This makes it the only material suitable and approved for inverted roof applications. Rigid extruded polystyrene insulation has minimal water absorption due to its closed cell structure.

An inverted roof is quite simply where the waterproofing layer is installed over the structural deck rather than over the insulation.