The aluminium ‘F’ profile is used with glazing bar systems to support the first and last sheets of polycarbonate glazing sheet fitted on a roof. It is a cost-effective alternative to using a side profile within a glazing bar. Due to the wide coverage of the F profile jaws within which the polycarbonate sits - from 36 up to 46mm – this is a secure way of holding the starting and the finishing panels of polycarbonate glazing on a sloping roof with a minimum pitch of 10 degrees. Fix the F profile through its stem every 300mm. Add a bead of silicone (that is compatible with polycarbonate) where the sheet joins the F.