Bill –
So it sounds like you have a corrugated metal roof installed by a handyman over an existing comp shingle roof? It might be wise to get your building department planchecker or inspector involved at this point since it sounds like you have a potential code violation. Adding PV to an already shotty roof setup will just compound problems down the line. That said, if you can’t trust the purlins (or what I think you are referring to as 1” x 4” stringers) to be structural members, then I suppose you could install long hanger bolts all the way through the metal roof and into the rafters? You could use a double jam-nut setup to mount your racking. Just an idea, but it is not an ideal situation. Good luck out there! Best, August *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *frenergy *Sent:* Saturday, April 30, 2016 7:47 AM *To:* RE-wrenches *Subject:* Re: [RE-wrenches] Goofy roofing Benn, August, etc Sorry for omitting a somewhat crucial detail....below these stringers it is a "standard" residential stacked roof with 2X6 rafters on 16" centers with 1/2 " plywood deck. No purlins. I appreciate the feedback/good ideas. Bill Feather River Solar Electric On 4/29/2016 3:28 PM, August Goers wrote: Benn, We’ve done it several ways including putting four 14 x 1.5” TYPE 17 screws per attachment point through the metal and into the 1” x wood purlin. The key is that the load path all the way down needs to be capable of handling the worst case loads. So we had to check that too. Some racking manufactures such as Unirac have online calculators to give point loads. Best, August *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *Benn Kilburn *Sent:* Friday, April 29, 2016 2:17 PM *To:* RE-wrenches *Subject:* Re: [RE-wrenches] Goofy roofing August, et al; If the purlins are only 1"x4" or 1"x6" or....1"x anything, are you only relying on the 1" purlin as the attachment point or are you hitting the vertical trusses below the purlins? We are working on a corrugated roof right now and using a Schletter roof bracket. The name of it escapes me at the moment. Maybe FixT? We are attaching to purlins which are 2"x6". I wouldn't think 1"x anything would provide enough pull-out? Benn Kilburn SkyFire Energy Inc. 780-906-7807 On Apr 29, 2016, at 9:09 AM, August Goers <aug...@luminalt.com> wrote: Hi Bill, It sounds like you’re talking about a purlin type setup – 4’ sounds a little far apart but I guess that’s what you have to deal with. If you have a corrugated metal roof, we’ve used S-5 CurruBrackets screwed through the metal and into the purlins and then either run the solar rail up and down the roof or install a sub-rack system (with strut or angle aluminum) perpendicular to your solar rail. Best, August *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On Behalf Of *frenergy *Sent:* Friday, April 29, 2016 6:55 AM *To:* RE-wrenches *Subject:* [RE-wrenches] Goofy roofing Recently, a customer had a metal roof (not standing seam) installed by a "handyman". Pretty clean installation however for some reason he ran 1X6 stringers across the roof on the 1/2" plywood deck spaced about every 4 feet (as you go from ridge to eaves). Of course the roofing screws are at the stringers. I'm sure he had a *great* reason for doing so. So now I have been asked to install an array on this roof. You can feel how "soft" the roof is as you walk on it of course because you are walking on air-below-metal for most of the roof. Stringer locations don't jive with possible feet/post locations for rail. I'm usually pretty good at problem solving but I'm accepting ideas. Bill Feather River Solar Electric Bill Battagin, Owner 4291 Nelson St. Taylorsville, CA 95983 530.284.7849 CA Lic 874049 www.frenergy.net _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org -- Feather River Solar Electric Bill Battagin, Owner 4291 Nelson St. Taylorsville, CA 95983 530.284.7849 CA Lic 874049 www.frenergy.net
_______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
