<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">It may be helpful to distinguish between exposed-fastener metal roofs and other roofing systems. </div><div class=""><br class=""></div><div class="">If you’re working on a metal roof that is attached with exposed fasteners, I don’t know of any practical solution for retrofitting PV without adding more exposed fasteners. And, yes, the mastic under the L-foot will likely outlast the waterproofing around the roof attachments.</div><div class=""><br class=""></div><div class="">However, according to conversations I’ve had with James Kirby, exposed fastener metal roofs are not an NRCA-approved/recognized roofing system. The waterproofing methods on exposed-fastener metal roofs are inherently inconsistent with NRCA standards. </div><div class=""><br class=""></div><div class="">Other roofing systems are consistent with NRCA standards. If you don’t use flashing with these NRCA-approved roofing systems, your PV attachment method is going to compromise the waterproofing for the roof system. </div><div class=""><br class=""></div><div class="">You can’t really argue that point, because there are established standards that apply to flashing and waterproofing according to roof type.</div><div class=""><br class=""></div><div apple-content-edited="true" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px;"><div class="">David Brearley</div>Senior Technical Editor, <i class="">SolarPro</i> <div class="">NABCEP Certified PV Installation Professional</div><div class=""><a href="mailto:david.brearley@solarprofessional.com" class="">david.brearley@solarprofessional.com</a></div><div class="">Direct: 541.261.6545</div><div class="">Follow us on Twitter: @SolarPro</div><div class=""><br class=""></div>Check out this AMAZING music video tribute to SolarPro: <a href="http://bit.ly/1qfMCCh" class="">http://bit.ly/1qfMCCh</a><br class="Apple-interchange-newline"><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"></div></div><br class=""></body></html>