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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Jason makes an interesting point.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I also think that flashings should always be used, but bear in mind that with asphalt shingles, and most roofing systems for that matter (membrane roofing is one exception), the shingles themselves are not really the “waterproof” part of the roofing assembly. The underlayment is.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">The primary purpose of the shingles, and the flashings, is to shed the majority of the water, and to provide physical protection for the underlayment from the elements and protection from UV light degradation. And of course for visual esthetics.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">It’s very important that the penetration through the underlayment be sealed properly. I’ve always thought that the reason we don’t see more leaks from L-feet on top of the shingles is because of the clamping pressure from the lag bolt compressing the layers of roofing materials. Water is a fairly thick fluid, and even though you can get capillary wicking between the materials, it needs to be a relatively large gap for the water to wick between the layers. </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I think that the best way to seal roof penetrations is to mount the L-foot or standoff directly to the underlayment, using a double sided butyl material, or something similar that is compatible with the underlayment material. Then the upward penetration of the L-foot or standoff through the shingles should be flashed. Of course, this is not easy to do on a retrofit job, but would be the way to go on a new roof installation.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Many roofers, especially in snow zones, are moving into using self-adhering underlayments, which also offer better sealing of all of the nail penetrations. Basically, it has a sticky butyl or asphalt-based layer in contact with the sheathing, with a non-sticky top surface. This makes it self-sealing to all the nail and screw penetrations. </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Some roofing systems are even moving to the “rain-screen” idea, that being that there is actually a gap engineered into the system between the underlayment and the final roofing material. This allows any water that gets past the top-layer roofing to have a clear pathway to drain down the slope of the roof and out the edge of the eve. Furring strips are used to give a 3/8” or larger gap. This also allows air flow into the roofing system to aid is drying out any moisture that does enter. This also might make the use of flashings less imperative, since all the true waterproofing is at the underlayment level, not at the shingles of other final roofing.</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Brian Teitelbaum</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">AEE Solar </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> RE-wrenches [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Jason Szumlanski<br><b>Sent:</b> Thursday, August 06, 2015 11:05 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] to flash or not to flash</span></p><p class="MsoNormal"> </p><div><div><p class="MsoNormal">If we are talking code, we should also point out how people are "getting away" without using flashings and why AHJs are not requiring them. What I have seen is that a fastener is not considered a "penetration." The argument used frequently is that the thousands of screws that attach an exposed fastener metal roof are not "flashed." The argument goes that the codes sections cited be Andrew are intended for large openings like roof vents and plumbing vents. If the screw occupies the space of the "penetration" and is further sealed with sealant or a gasket, there is no flashing required. You could extend this argument to shingle nails that go through the "roof plane" depending on how you define it.</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Don't kill the messenger - I'm just pointing out the logic/argument made against the requirement for flashings.</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">I'll reiterate that my vote is to flash!</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Jason</p></div><div><p class="MsoNormal" style="margin-bottom:12.0pt"> </p><div><p class="MsoNormal">On Thu, Aug 6, 2015 at 1:04 PM, Andrew Truitt <<a href="mailto:atruitt@gmail.com" target="_blank">atruitt@gmail.com</a>> wrote:</p><div><p class="MsoNormal"> </p><div><p class="MsoNormal">Flash! It provides a better, longer-lasting seal, and its a Code requirement in most jurisdictions. From the IBC via the Quickmount PV website:</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"><img border="0" width="562" height="322" id="_x0000_i1025" src="cid:image002.png@01D0D03C.45CD4500" alt="Inline image 1"></p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">If one chooses to attach a footing directly to the roof without an integrated flashing then an "insurance option" is to install an 8" step-flashing under the shingle course above the penetration. This works better for railed systems than railless since the whole footing assembly can be covered by the modules.</p></div><div><div><div><div><div><div><div><p class="MsoNormal"> </p><div><div><div><div><p class="MsoNormal"> </p><div><p class="MsoNormal"> </p></div><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#38761d">For a brighter energy future,<br><br><br>Andrew Truitt </span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#38761d">Principal<br>Truitt Renewable Energy Consulting, LLC</span></p></div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#38761d"><a href="tel:%28202%29%20486-7507" target="_blank">(202) 486-7507</a></span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><a href="https://www.linkedin.com/in/andrewtruitt" target="_blank">LinkedIn Profile</a></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><a href="http://truittreconsulting.weebly.com/" target="_blank">Company Website</a></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#38761d">NABCEP Certified PV Installation Professional ID: 032407-66</span></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="color:#38761d">Colorado Journeyman Electrician License No.: 600132</span></p></div></div></div></div></div></div></div></div><div><div><div><div><div><p> </p></div><p class="MsoNormal" style="margin-bottom:12.0pt"> </p></div></div></div></div></div></div></div></div></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"> </p><div><div><div><p class="MsoNormal">On Thu, Aug 6, 2015 at 10:47 AM, Daniel Young <<a href="mailto:dyoung@dovetailsolar.com" target="_blank">dyoung@dovetailsolar.com</a>> wrote:</p></div></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><div><div><div><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Writing the subject above, it seems like I’ve heard this question on the wrench list before, but I could not find it in my old email archives. Feel free to pint me back to the old discussion if it’s there.</p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I’ve been using a flashing based roof attachment for 8+yrs now (quick mount or similar). Now we are looking at Rail-less systems (quick rack is a good example). There is also a non-flashed rail-less racking from roof-tech <a href="http://roof-tech.us/" target="_blank">http://roof-tech.us/</a> . I’ve always been of the opinion that simply crushing some sealant/gasket onto an asphalt shingle work fine at first (the test data from roof-tech is impressive), but would be an issue 10+yrs down the road (thermal expansion movement, freeze/thaw, etc). I can make a good waterproof seal at first by just slathering some butyl/silicone to an L-foot and cranking it down on the shingles, but that practice really disappeared 8+yrs ago.</p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Maybe consider this a Poll: (to flash, or not to flash) </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">With Regards,</p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Daniel Young, </p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">NABCEP Certified PV Installation Professional<sup>TM</sup>: Cert #031508-90</p></div></div></div></div></blockquote></div></div></div><p class="MsoNormal"> </p></div></div></div></div></body></html>