Re: [RE-wrenches] No underside access metal biulding attachment

[Allan Sindelar]

Lars, This has been addressed before on this list, but its been awhile. #14 self-tapping ("Tek") screws have phenomenal pull-out strength in standard steel purlins. My advice is to research this through your fastener supplier; I have seen charts on pull-out strength of various sizes and materials. I think you'll find that you can come up with a screw attachment schedule with which you'll be satisfied. Allan Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer NABCEP Certified Technical Sales Professional New Mexico EE98J Journeyman Electrician Positive Energy, Inc. 3201 Calle Marie Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com On 3/15/2012 10:26 AM, lars Ortegren wrote: Wrenches, We have a project coming up where we are installing a large array on a low slope metal building with metal purlins. Typically we would through bolt our attachment to the purlins, but in this case the building is a self-storage, and access is not an option. Does anyone out there have experience with any top side only metal-metal attachments? I’ve thought about using some larger sized stainless self-tapping screws, but I worry about the pull out strength (as the roof combined with the c-channel purlins are only about 1/8”) and the effects of heat and cooling of the roof backing the screws out over time. Any thoughts ?   Lars Ortegren   Director of Operations California Solar Electric Company 10141 Evening Star Drive, Suite 6 Grass Valley, CA 95945 http://www.californiasolarco.com/   Phone : (530)274-3671 Fax: (530)274-7518   California C-10 Electical Contractor #779624 NABCEP Certified PV Installer # 091110-89 Certified NABCEP Continuing Education Provider More about NABCEP:   http://www.nabcep.org/   _______________________________________________ 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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