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. 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. In an inverted roof construction the principal thermal insulation layer is located not only above the roof structure but also above the waterproofing resulting in the waterproofing structural deck and support structure being at a temperature close to that of the interior of the building. Rigid extruded polystyrene insulation has minimal water absorption due to its closed cell structure. Inverted roofs are designed with the waterproofing layer usually a liquid applied membrane beneath the insulation.

Simply defined as a type of roof construction where the waterproofing layer lies beneath the insulation instead of above it as in other forms of roofing inverted roofs ensure that the complete roof construction including roof covering is kept at warm temperatures during winter months and at moderate temperates during the summer months. 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 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. No vapour control layer is required.

Insulation boards are loose laid on top of the membrane and then weighted down with paving slabs or gravel ballast.