I would certainly agree with Will here. You can't make that argument as stated, it's wrong. Please don't try to make it to your AHJ, you take the chance of f-ing it up for everyone around there. I think the best argument you can try is: aside from the usual 3-4lbs/sq/ft that the array itself ads to the roof load, snow will be very unlikely to build up on the modules to the degree that it builds up anywhere else on the roof. The freezing-rain-before-a-snow phenomena is very real and it WILL happen sooner or later. Not often perhaps and under most conditions the snow will leave the modules before the roof. But...Gotta be real about that. Bob-O Schultze
On Feb 19, 2013, at 11:06 AM, Will White wrote: Most structural engineers I’ve seen take a reduction for slippery surface but I think you’d be stretching things to say adding PV panels reduces the load to zero. I have a 45 degree pitch roof and I get snow build up some times especially if we get freezing rain before the snow. Also if you have an asphalt shingle roof you can create an unbalanced load with snow sliding off the south side and sticking on the north side. Most engineers take this into consideration too. Thanks, Will __________________________________________________________________________________________ Will White Regional Field Operations Manager – New England Real Goods Solar 64 Main St. Montpelier, VT 05602 Tel: (802) 223-7804 Cell: (802) 234-3167 www.realgoodssolar.com From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Gary Bassett Sent: Tuesday, February 19, 2013 1:48 PM To: re-wrenches@lists.re-wrenches.org Subject: [RE-wrenches] Snow loads Has anyone in the snow belt areas have any luck with convincing their local building inspectors that the snow melts or slides from panels, much like a metal roof only better. Thus your snow load would be reduced to zero where the panels have been installed. Gary _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
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