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. <div>
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.<div><br><br><div class="gmail_quote">
On Sun, Jul 1, 2012 at 9:13 PM, <span dir="ltr"><<a href="mailto:mark@hurshtown.com" target="_blank">mark@hurshtown.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><span style="font-size:10pt;font-family:Verdana"><div><font face="verdana, geneva">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.</font></div>
<div><font face="verdana, geneva"><br></font></div><div><font face="verdana, geneva">Mark</font></div>
<blockquote style="padding-left:8px;border-left-color:blue;border-left-style:solid;font-size:10pt;margin-left:8px;font-family:verdana;border-left-width:2px">
<div><div class="im">
-------- Original Message --------<br>
Subject: Re: [RE-wrenches] L feet no flashing in shingle roof<br>
From: Drake <<a href="mailto:drake.chamberlin@redwoodalliance.org" target="_blank">drake.chamberlin@redwoodalliance.org</a>><br>
Date: Fri, June 29, 2012 3:09 pm<br>
To: RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>><br>
<br>
Hi Jay, <br><br> 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. <br>
<br> <br> <blockquote type="cite">And given that we have really good off the shelf approved flashed feet, why would you use anything else?<br><br> My 2 cents,<br><br> Jay<br><br> peltz power<br><br> <br> On Jun 29, 2012, at 5:16 AM, Glenn Burt wrote:<br>
<br> <blockquote type="cite">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.<br> <br> 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.<br>
<br> <br> <br> Glenn<br> <br> <b>From:</b> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank"> re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Drake<br>
<b>Sent:</b> Thursday, June 28, 2012 6:40 PM<br> <b>To:</b> RE-wrenches<br> <b>Subject:</b> [RE-wrenches] L feet no flashing in shingle roof<br> <br> 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.<br>
<br> 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?</blockquote></blockquote>
<u></u></div><div> <font>Drake Chamberlin<u></u> <u></u> <br><div class="im"> ATHENS ELECTRIC LLC<br> OH License 44810<u></u> <u></u><br> CO license 3773<br> NABCEP Certified PV<br> </div></font> </div><hr>
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