How Does Warm Weather Damage Flat Roofing?

21st April 2014

Flat Roofing vs Warm Weather

As the summer fast approaches, and the UK steers slowly away from the effects of one of the worst winters in decades, we can begin to assess the damage to flat roofing. Many people assume that the worst damage that a flat roof can sustain will be from heavy rain, driving winds and frost; this may be true, but warm weather can be just as harmful to traditional felt roofing.


As a felt flat roof ages, exposure to the sun can cause bubbles and blisters to appear, which, if not treated quickly, can crack and result in areas where leaks can occur. During the winter, or during prolonged periods of heavy rain, these leaks manifest pretty quickly. During dry spells, these leaks can go unnoticed for weeks, sometimes months, not making themselves known until the wintry seasons reappear.

Flat roofing is subjected to the elements all day, every day and felt is notorious for ageing poorly. Hot sunshine partly melts the bitumen-based flat roof covering, which encourages blisters to appear and then the cracks, which allow water ingress that can sit in the joists of a flat roof structure. Once winter comes around again, freezing temperatures can cause problems in those joists as the water expands and damage is exacerbated.

Once this occurs, the process of repair can become far more costly. Felt roofing can be patched, but, once compromised, is unlikely to withstand the rigours of another winter, particularly if the conditions are as wet and windy as we have just experienced!

It is worth investing in more modern materials that weather far more effectively than felt. Firestone’s EPDM membrane is a flexible rubber-based material that is guaranteed for 20 years and carries a life-expectancy of more than 50! EPDM is a system that is fast and easy to apply, using only cold adhesive application of a one-piece membrane that requires no joins, minimising the risk of water seepage through the vulnerable areas.

Manufactured in the U.S.A. EPDM has been utilised on commercial and industrial flat roofing for many years and has a proven track record all over the world. In more recent times, roofing specialists have realised the potential for EPDM roofing materials for domestic roofing as an effective alternative to the felt roof have been sought.

So, before the summer is over, take a look at your flat roof to check for signs of damage. Regular checks are critical with a traditional felt roof covering to ensure expensive flat roof repairs are avoided.

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