Roof Tech Inc. a global leader in the Rail-less roof top PV mounting systems has added engineering to support 72 cell PV modules or modules up to 21 sq. ft. The new engineering data was added to their already extensive engineering reports created by Starling Madison Lofquist, Inc., a well respected 3rd party firm that created the full reports from actual load testings. The simple to use tables are compliant with the IBC 2012, with values according to the roof zones, type of exposure and different attachment methods at different roof pitches. Astounding results with top basic wind speed up to 180 mph and Ground Snow loads up to 113 psf.
The PE reports include tables for rafter attachment (2"x 4", 24" o.c.) and direct to the roof decking (7/16" OSB and 15/32" Plywood thickness) applications which are not yet common to the US PV industry. Direct to deck attachment is a true game changer and helps to lower the time on the roof dramatically. Unlike the common method of securing a PV system with lag bolts, Roof Techs approach is with the use of multiple 5mm stainless wood screws making the roof decking installation evenly secured. If the PV system needs to be secured to rafters, the overall installation becomes even easier to meet code because the 5mm screw will need to hit within 60% from the center of the rafter. A 5/16" lag bolt will need to hit within 30% from the center of the rafter which is a much narrower tolerance and therefore much more difficult to comply with the code.
At this time only the E Mount AIR is being certified for the use of 72 cell modules.
For more information on Roof Tech or to download the new PE reports, please visit www.roof-tech.us or call (619) 551-7029