The rafter tray maintains a clear air space of 25mm from the eaves to the roof void, by creating a barrier for the roofspace insulation. Features Structurally profiled. Better rigidity than standard continuous rafter trays. Maintains a full 25mm air path down the line of the roof. 800mm deep. Will cover a 200mm depth of insulation at a minimum 15pitch, 250mm at a minimum 18pitch, 300mm at a minimum 22pitch or 400mm depth of insulation at a minimum 30pitch