Inverted Flat Roof Insulation

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

Inverted flat roof insulation.

An inverted roof is quite simply where the waterproofing layer is installed over the structural deck rather than over the insulation. This makes it the only material suitable and approved for inverted roof applications. The inverted roof insulation protects the membrane from extremes of weather such as frost uv exposure and the expansion and contraction that comes about from summer winter temperature cycles. However there are other products on the market such as enertherm xps plus which outperform traditional xps boards.

Benefits of inverted roofs. It is worth considering that standard xps and eps inverted roof insulation is not as thermally efficient as pir insulation when used as part of a standard warm roof design. Ravatherm xps x has been created specifically for inverted roofs a form of flat roof where the thermal insulation is placed above the waterproof membrane. Insulation can either be put below the weather proof membrane which is called a warm roof deck construction or above the waterproof membrane which is called an inverted warm deck.

Project specific proposals or solutions are. Foamglas inverted roof systems inverted roof with non combustible insulation on a continuous support foamglas invatherm loose laid double layer system 2 4 system 4 8 3 7 8 schematic drawing 9 5 solutions for technical details and specification clauses can be provided on request. A the permanent protection of the waterproofing membrane of the overlying layers from factors such as solar radiation extreme temperature variations mechanical stresses etc. Rigid extruded polystyrene insulation has minimal water absorption due to its closed cell structure.

The standard design consideration is that the rain falling on the roof filters through the ballast and between the insulation boards until it reaches the membrane and then drains away through rainwater outlets. The great benefit of inverted roofs is that the insulation protects the membrane from extremes of weather such as frost uv exposure and the expansion and contraction that comes about from summer winter temperature cycles which can be as much as 80 c on some roofs. The added benefit of this type of roofing is that the membrane is also protected from expansion and contraction caused by changes in the weather and temperature. The only point of putting the insulation on top of the waterproof membrane is when you can t take it off as when for example it is bitumen.