Inverted Warm Deck Roof

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.

Inverted warm deck roof.

Benefits of inverted roofs. In a warm roof construction the principal thermal insulation layer is located above the structural decking. Inverted roofing is typically installed on a concrete deck because a loading of 80kg m2 is required to retain the insulation on the roof. This video will demonstrate how to install a cure it grp waterproofing system in a warm roof build up.

The system is also referred to as a protected membrane or upside down roof. Good question theoretically when building a warm roof the vaper control layer goes on the warm side of the insulation. This type of roof has normally been used over small extensions to dwellings using timber joists and plywood. Glue laminated timber is also sometimes used.

If you put insulation under the decking and between the joists you lower the temperature of the decking and lower the due point thus bringing it closer to the danger point of being in the building. Flat roof construction thermal design and condensation warm roof. Inverted roofs are a type of warm flat roof where the insulation is above the waterproofing layer. In situ concrete is the easiest to apply ideally without a screed to falls see zero falls below as this can complicate the application and delay the installation programme.

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 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. 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.