ABSTRACT
INTRODUCTION A flat roof is a roof with a pitch of less than 10 degrees. It has been a common alternative to the pitched roof for the last 50 years or so and its popularity is based on its cheaper initial capital cost. This is as a result of its easier construction and use of less material than a pitched roof of comparable plan size. However, a flat roof does not perform as well as a pitched roof when long-term costs are taken into account. The roof covering materials are, generally, not as durable as those used on pitched roofs (although metals such as lead and copper are the exception) and the extremely low pitch means that a flat roof is less efficient in drainage terms. It tends to be much more prone to leakage and water-related problems. Recent advances in material technology have addressed some of the concerns of durability and weatherability.
