Do flat felted roofs need to be covered with stone chippings or slate granules?
No, in normal circumstances only those bitumen felts manufactured using SBS modified or Oxidised bitumen compounds require protection from ‘ultra violet radiation’ as given off by the Sun’s ray. Although stone chippings and slate granules in addition to providing protection for the roof from ultra violet radiation, they also providing a decorative finish and can reduce problems caused by extremes of temperature and surface spread of flame. Waterproof membranes manufactured using an APP modified bitumen compound, although not requiring protection from the Sun’s rays to the same extent as SBS modified or Oxidised bitumen compounds, stone chippings or slate granules do provide decoratively pleasing finish and can reduce problems caused by extremes of temperature and surface spread of flame.
