How to spot a damaged flat roof - e.surv Chartered Surveyors

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How to spot a damaged flat roof

When purchasing a property with a flat roof you should consider its condition. Although they're the cheaper option when building properties, it can be costly in the long-run if they've not been properly maintained. Read here how to spot a damaged flat roof.

When purchasing a property with a flat roof, there are a few key things to think about concerning its condition. Flat roofs are a fairly modern feature when it comes to housing, and although being the cheaper option when building properties, it can turn out to cost more in the long-run.

The most common covering of flat roofs is felt – especially on flat-roofed extensions. It is a widely held belief that felt coverings last around 15 years, however, if regular inspections and maintenance have not been conducted, premature failure can occur.

Flat roof drainage is not as effective as a pitched roof and has a higher chance of leaking if not regularly inspected. If the flat roof to the house you are buying has not been well maintained, it could represent a cost to you in future.

Tell-tale signs of damage to a flat roof

During the spring and autumn there is a higher volume of debris and leaves. Look for debris and dirt preventing proper drainage which may result in damage of the waterproofing sealant on the flat roof.

You should look out for water gathering in pools on your flat roof. Known as ‘water ponding’, the pools of water can damage your roof covering over the long-term if not addressed. The existence of moss or light plant growth can also provide signs that your flat roof may be affected. A leak may cause damage to internal finishes and at worst can lead to failure of supporting timbers.

Other defects to be aware of include splits, cracks, blisters or bumps to the flat roof covering.


If the house you are about to purchase has good flat roofs, we would still advise undertaking some basic maintenance to increase the lifespan of your flat roof. For example, after a storm, it is sensible to carry out a quick inspection of the gutters and rainwater outlets, to ensure they are clear from dirt and leaves.

Solar reflective paints and gravel are a great way to reduce fungal growth and improve the weather-proofing of flat-roofed properties. While this can be conducted by the homeowner, we would advise taking great care, especially when using ladders or going onto the roof covering.

We recommend hiring a professional company, not least because any foot-traffic on the roof may also cause lasting damage.

If you have found a property that you are keen to purchase but are concerned about the flat roof, or any other defects to the property, please don’t hesitate to contact a member of our team to discuss our RICS home surveys: