Roof insulation drainage system involves cutting runoff channels off main ridge to eaves groove to divert descending water out onto insulation clear of roof vents.

摘要

Water running down the groove from ridge to eaves is repeatedly led out onto the foam element surface (33) using water channels (32) diagonal to the foam insulation surface and at an angle to ensure fall towards the eaves whatever the angle of the roof. The channel forms an indentation arranged so the water in the drainage groove from ridge to eaves is automatically diverted onto the foam surface clear of possibly vented roof interior.