Flat Roofs

Flat Roofing: Considering the Implications

Are you looking to buy a new home or perhaps thinking of building an extension? Have you considered the implications that a flat roof may cause on your property?

Flat roofs are generally quicker and less expensive to construct when compared to traditional pitched roofs. They are however much more likely to suffer leakage due to their less effective drainage methods, and ongoing maintenance costs can be significantly highly. Of course with professional installation, they still make for a fantastic option when considering an extension to an existing space.

In our continuing quest for more space, it is more common than ever to see flat roof extensions in the gardens of houses throughout the UK. Despite the increased popularity, the building methods remain much the same as they were throughout the 20th Century.

Felt Roofs

With felt (a.k.a torch on felt) continuing to be a popular covering for flat roofs, it is commonly thought that this material has a life span of 10 – 15 years, this is in fact not true. With good maintenance and upkeep, felt can last for many years beyond the much quoted 10 – 15 year expectancy.

Other Commom Materials

  • Ethylene Propylene Diene Monomer or better known as EPDM is an extremely durable synthetic rubber. EPDM roofing is increasing in popularity in the UK but it does bring a price point of around 30% more than the price of felt.
  • Fibreglass also know as GRP roofing can last for a minimum of 30 years with little or no deterioration. GRP does have a high price tag due to greater material costs.
  • Mastic Asphalt is a highly durable option with long-term performance. With its exceptional versatility it be easily laid over curving surfaces to form a continuous waterproof layer.
  • Lead is one of the most traditional materials laid on flat roofs, its use dates back hundreds of years. Used correctly and at the right thickness it can last for 100 years or more. In modern day use, it is more regularly used for smaller sections of flat roof such as above bay windows.


It is recommended that you have any flat roofs inspected by a professional on a biannual basis to ensure the proper clearance of any debris, leaves and to maintain proper drainage to prevent leaks.

Advising Your Insurer

With any flat roof, it is likely a condition of your policy that you must inform your insurance provider, even if you only have cover for your contents.

Header image: House by canal with modern extension (David Hawgood) / CC BY-SA 2.0