The issue of ponding can be bad news for your flat roof and is the first sign that the roof needs attention – fast. Ponding occurs after a spell of rain and looks exactly as it sounds – ponds of water appear across the surface of the flat roof, and sometimes remain there up to 48 hours later.

What does ponding on a flat roof look like?

If your roof looks like it has ponds on it after a heavy downpour, it is likely that there is an issue with drainage. Another sign is circles of algae or dirt on the surface of the flat roof, indicating that ponding is occurring.

Ponding can also indicate that the structure of the roof deck itself is affected, as sagging of the roof structure creates an uneven surface that allows water to pool. Poor flat roof design is also a contributory factor to ponding. The roof deck should be designed to have an accurate slope to enable water to drain away effectively.

Whatever the cause, ponding issues should be addressed quickly after discovery, as ignoring such problems can lead to water ingress and subsequent leaking, which can cause expensive damage to both the remaining flat roof and the interior of the building. Ponding water can grow more serious if left, and the additional pressure a pond or pool of water creates can force water through the tiniest holes or tears in the flat roof materials. In the worst-case scenario, additional weight caused by a water pond can cause the roof deck to collapse. Ponding water can weigh up to 5lbs per square foot of roof deck! Therefore, it is critical to realise that ponding is a problem that cannot be ignored.

What you can do to address ponding on your flat roof

The first thing to do is to check the gutters all around the flat roof. Gutters and downpipes are the primary source of drainage across the roof. Make sure all are clear of debris, and check that there are enough drainage points. If the roofing material is felt, there is a good chance that it is reaching the end of its lifecycle, and it should be replaced. Felt is a traditional roof covering that is fast becoming outdated, as the latest single-ply membranes have a far superior lifespan. Spending a little more on a product such as EPDM membrane, for example, will pay off significantly in the long term.

How Permaroof Peterborough can help you

Permaroof Peterborough is your local roofing contractor, trusted, registered and fully insured to carry out all your flat roof repairs and replacements. We’re experienced and really want to help local homeowners to get the most from your flat roofing and find the sustainable solution you’ve been looking for.

EPDM rubber roofing systems do offer unmatched longevity with an expected lifespan of more than 50 years. Call us and book a no obligation survey and quote or visit the flat roofing page to find out more.