Christopher Lee, quantity surveyor with Capita, looks at roofing finishes
There is a vast and varying spectrum of roof finishes; tiles, built up roofing, single ply membranes, metal sheet cladding, timber, green roofs, etc. Most can be applied as either pitched or flat roof finishes. A flat roof is generally defined as having a pitch of 10° or less.
Typically, compared to a flat roof, a pitched roof will require about 10% additional roof covering, although clearly this assessment also depends on the particular circumstances.
Many factors influence the selection of a roof finish and consideration must be given to all, particularly to the use of the space below the roof and how that may be affected by the specified finish.
It is critical to the installation of all roof finishes to make sure contractual responsibility for design detailing is defined and clear.
As the applied finish plays such a critical part of the building’s life it is always worth considering taking up a latent defects warranty.