GreenTips

When using flat roofing, aim to minimise the replacement frequency of the underlying membrane. Protect the membrane from UV damage and traffic by surface coverings such as insulation slabs, concrete slabs, gravel, etc.

Light coloured membrane and light coloured gravel finishes can dramatically reduce the solar gains on the roof.

Upside down roof constructions with the insulation laid in panels over the membrane is another good way of increasing the life of the membrane and reducing solar loads. In concrete roofs this has the added advantage of keeping the thermal mass within the insulated envelope.

Green roofs have recently become popular for their potential to increase insulation levels, absorb stormwater and increase local biodiversity. Green roofs do need to be detailed with care as they can add to the load that the roof structure must support, therefore increasing cost.

When choosing a membrane, ensure it does not fully adhere to the substrate. This will allow recycling of the roof to be carried out more easily.

A number of roofing membranes contain chemicals that can be harmful to human health. In particular, the hot application of bitumen and mastic and the spray application of other man-made chemicals should also always be treated with care.

Some types of membranes on the market, such as those manufactured from ethethyne propylene rubber, are available as lower toxicity alternatives to more traditional coverings.

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