Traditionally flat roofs have been constructed from three-ply modified bitumen roofing (also known as felt flat roofing) which, while historically a popular choice, has some disadvantages, particularly its susceptibility to UV sunlight and heat in addition to its somewhat limited lifespan. A viable alternative is Ethylene Propylene Diene Monomer (EPDM), a rubber membrane which has a number of advantages over felt flat roofing. The standard membrane thickness is 1.1 mm (often confusingly referred to as "45 mil").
Fixing new decking to renovate an old flat roof.
The extended lifespan of EPDM compared to other forms of roof membranes needs to be taken into account when considering its cost effectiveness. While its longevity depends on a number of factors, with professional installation and maintenance laboratory tests have demonstrated that it is possible for an EPDM surface to last in excess of 40 years. While the initial cost of installing an EPDM roof may be higher than a
traditional three-ply modified bitumen roof, the increased lifespan will more than recover the costs in the long term.
EPDM offers a watertight solution. Also it is a very lightweight material which can be easily shaped to fit the contours of the roof and, in the unlikely event of rips or punctures to the rubber, can be repaired simply.
With the ability to expand or contract according to the prevailing weather conditions, EPDM is highly resistant to extremes of temperature in the range -50°C to +150°C. Wind and standing rainwater does not compromise the surface and EPDM insulates heat effectively meaning internal rooms are cooler in summer and warmer in winter.
Due to its extended lifespan, EPDM is recognised to be an environmentally friendly material with significant advantages over other types of roof membranes. Both Greenpeace and ACTAC (The Association of Community Technical Aid Centres) have named EPDM to be the leading choice for roofing where environmental sustainability is concerned.
