Inverted Flat 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 flat roof.

Good insulation qualities and low thermal conductivity are required to ensure the low u value of the roof. Then aquazone a high performance non woven polyethylene membrane is installed over the insulation to minimise the cooling effect associated with rainwater flowing down through the insulation and draining away. Rigid extruded polystyrene insulation has minimal water absorption due to its closed cell structure. It is therefore essential the insulation layer is rot proof and durable.

What is an inverted roof. In this type of construction the principal thermal insulation material is applied on top of the weatherproof covering so that the complete roof construction including roof covering is kept at warm temperatures during the winter months and at moderate temperatures during the summer months. An inverted roof is quite simply where the waterproofing layer is installed over the structural deck rather than over the insulation. What is an inverted roof.

The inverted waterproofing insulation system is applicable for all types of flat roofs as it offers an efficient solution for new construction but also for renovation of old flat roofs as is it possible to install an inverted roof over an existing roof build up. The mariseal system inverted flat roof waterproofing method offers a simple build up waterproofing that features a protected waterproofing membrane and loose laying insulation boards. Insulation boards are loose laid on top of the membrane and then weighted down with paving slabs or gravel ballast. In an inverted roof construction the sika trocal membrane is installed directly to the structural decking usually concrete and the innobond thermal insulation is installed on top of the membrane.

Inverted roofs are designed with the waterproofing layer usually a liquid applied membrane beneath the insulation. This makes it the only material suitable and approved for inverted roof applications.