If installing on a roof with a pitch greater than 10° then DriStud roofing underlays may be installed either horizontally or vertically.
If the roofs pitch is 10° or less it is recommended to be run horizontally with the higher layers sitting on top of the lower layers. It can be installed without supporting netting for horizontal installation.
When it is not practical to place underlay horizontally, DriStud FRU36 can be run vertically on a minimum side lap of 150 mm. Self-support roof underlays must be installed on supporting netting or equivalent system.
The netting and underlays must be installed flat and taut to ensure condensation will drain to the gutter. If any doubts vertical laps are recommended to be sealed with 75mm DriStud Cool window flashing tape or DriStud Joining Tape to ensure it.
DriStud FRU36 must have support on netting or safety mesh if used:
- On roof pitches less than 10° when installed vertically
- If support spacing > 1200mm
When DriStud roofing underlays are being used in conjunction with masonry tiles, anti-ponding boards should be used at the lower edges of the tiles.