I agree. I would drill a pilot for anything bigger than #12. 5/16" Lags get a 1/8" pilot minimum.
Unfortunately, common 1/8" bits are usually pretty short and break off easily. Jason Szumlanski Fafco Solar On Tue, Jul 3, 2012 at 9:35 AM, Chris Mason <[email protected]>wrote: > I don't believe you are correct here. The body of the lag does not do > anything for the holding power, it is the threads that prevent pullout. If > you drive a 5/16 lag into a 3 x 8 without a pilot hole, you will be putting > a lot of pressure into the wood to split it. It might not split every time, > it might not split right then, but you are definitely introducing a lot of > stress for no good reason. On any of these techniques for mounting, I want > to follow the manufacturers recommendations, otherwise how can you be sure > if you are right. Without a testing lab, you have no way to know. > I think mounting PV systems IS a science project, it takes care and > thought to do it right. We do a lot of concrete roof installations in > hurricane areas, and mounting keeps me up at night. > > > On Sun, Jul 1, 2012 at 9:13 PM, <[email protected]> wrote: > >> In my 20 year experience of lagging down L feet on shingle roofs in >> Indiana with a good dollop of silicone caulk under the foot, I've never had >> an issue. No pre-drilling, just drive the lag home. Drilling a hole first >> is not necessary, and reduces holding strength. No reason to make a >> science project out of it and increase cost and labor. >> >> Mark >> >> -------- Original Message -------- >> Subject: Re: [RE-wrenches] L feet no flashing in shingle roof >> From: Drake <[email protected]> >> Date: Fri, June 29, 2012 3:09 pm >> To: RE-wrenches <[email protected]> >> >> Hi Jay, >> >> There is no room for flashings. The L feet will go very close to the >> skylights and the flashing would hit the edge of them. Plus there is an >> existing array that was done by another installer that is done with L feet >> only. The new array would be higher. >> >> >> And given that we have really good off the shelf approved flashed feet, >> why would you use anything else? >> >> My 2 cents, >> >> Jay >> >> peltz power >> >> >> On Jun 29, 2012, at 5:16 AM, Glenn Burt wrote: >> >> We have used a variety of sealants over the years, and determined simple >> Henry roofing cement is the best product for use on comp roofing. >> >> We also used to bend our own L-foot flashing, which we cut from standard >> Al coil stock (before all the manufactured options were available). This >> might be a good option for you in this case. >> >> >> >> Glenn >> >> *From:* [email protected] [ >> mailto:[email protected]<[email protected]>] >> *On Behalf Of *Drake >> *Sent:* Thursday, June 28, 2012 6:40 PM >> *To:* RE-wrenches >> *Subject:* [RE-wrenches] L feet no flashing in shingle roof >> >> I'm quoting a job that has an existing array with L feet bolted down to a >> shingle roof with no flashings. I want to match the height of the existing >> array. Also some modules are being worked in around skylights where it is >> unlikely that room would be available for flashings to center over rafters. >> >> I've always used flashings. Would it be completely crazy to follow suit >> of the existing array and bolt L feet straight to the shingle roof with >> good roof sealant? If so, how would you seal it? >> >> ** >> Drake Chamberlin** ** >> ATHENS ELECTRIC LLC >> OH License 44810** ** >> CO license 3773 >> NABCEP Certified PV >> ------------------------------ >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: [email protected] >> >> 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 >> >> ** >> >> >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: [email protected] >> >> 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 >> >> >> > > > -- > Chris Mason > President, Comet Systems Ltd > www.cometenergysystems.com > Cell: 264.235.5670 > Skype: netconcepts > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > 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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