Inverted Flat Roof System

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

Inverted flat roof system. Insulation boards are loose laid on top of the membrane and then weighted down with paving slabs or gravel ballast. 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. Inverted roof systems a variation of a warm roof. The main difference between inverted roof systems and other roof systems is in the position of the waterproofing membrane.

This makes it the only material suitable and approved for inverted roof applications. Inverted flat roof waterproofing combined with a thermal insulation is essential for a buildings waterproofing and energy saving thermal insulation. Rigid extruded polystyrene insulation has minimal water absorption due to its closed cell structure. The upside down sequence means the deck is waterproofed first then insulated and finally finished with paving or ballast.

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. Inverted roofs are designed with the waterproofing layer usually a liquid applied membrane beneath the insulation. 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. Invented by dow in the late 1960 s an inverted roof system uses dupont styrofoam brand xps insulation to protect the membrane helping improve the performance and longevity of the entire roof system.