Laying of Single Skin and Built Up Insulation Systems
The pitch of the roof should be chosen to maintain efficient rain water drainage. Care should be taken to avoid reducing the pitch to produce minimal drainage conditions which could produce ‘ponding’ or, with driving winds, negative drainage.
Where corrugated profiles are used we recommend the roof pitch should not be less than 10 degrees. Using trapezoidal profiles the pitch can be reduced to 6 degrees. Where shallower pitches are envisaged we recommend that technical advice should be taken at the design stage to ensure that all necessary precautions are taken.