We recommend a slope of 3 inches per foot (3:12) or steeper for satisfactory performance of ONDURA panels and tiles. ONDURA should not be used on a slop that is lower than 3 inches per foot.
You can download a PDF version of the ONDURA Installation Guide under the Downloads section under Resources in the main navigation at the top of every page, or request one by email at tuftex-ondura@palram.com.
The support spacing of 24” on center (o.c.) is recommended. In areas of heavy snow loads, spacing should be reduced to 18” or 12”. Do not use 16” on center spacing, as this will not align correctly with the ONDURA corrugations to give the panel support. Wherever extreme conditions are possible or buildings have an interior ceiling, solid decking with felt is recommended.