Here is the flat roofed extension of a house in Blaby near Leicester.
It is old, allows rain to stand on it rather than drain freely away, and is split all down one side. Incredibly, there is no sign of dampness inside the kitchen but it is only a matter of time before that happens.
The property’s vendor claimed he was not aware of the problem. This clearly illustrates the importance of “looking up” and out of your windows from time to time to check for obvious defects such as this, slipped roof tiles, blocked gutters etc.
Flat roofs of all types do have a more limited useful life than a traditional pitched roof covering. For example, a mineral felt roof may last 10-15 years from new if properly maintained. Flat roofs can fail at any time and should therefore be checked periodically for potential defects.
It should be ensured leaf fall and other such debris is regularly removed and that where appropriate a protective layer of stone chippings is applied to the felt. It is unwise to allow storage upon them or to permit foot fall (window cleaners etc.) as they can be easily damaged. If they are replaced or repaired you may have to incorporate thermal insulation to comply with Building Regulations. For energy saving and environmental reasons it will be sensible to do so anyway. .