<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Hi All,<br><br>I am fully in favor of standardized permitting, and streamlining the process of installing PV. With that said, I do think the "one layer of shingles = PV on roof thing" is apples and oranges. Though the deadloading in psf is similar, PV doesn't sit on the roof, it lands on some sort of attachment, standoff, l-foot, what-have-you.<br><br>This leads to pretty high point loading values, doesn't it? If you spread your 1000 lb array around 300 square feet, you get your 3.3 psf, BUT if it lands on 30 L feet, each of 4 square inches you end up with much higher points of concentrated loading.<br><br>Anybody worry about that? <br><br>Thanks!<br>Wes Kennedy<br>NABCEPian<br> <br><br>--- On <b>Tue, 7/7/09, Joel Davidson <i><joel.davidson@sbcglobal.net></i></b> wrote:<br><blockquote style="border-left: 2px solid
rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Joel Davidson <joel.davidson@sbcglobal.net><br>Subject: Re: [RE-wrenches] Roof Loading request for help<br>To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org><br>Date: Tuesday, July 7, 2009, 7:13 PM<br><br><div id="yiv847054649">
<style>
<!--
#yiv847054649
#yiv847054649 p.MsoNormal, #yiv847054649 li.MsoNormal, #yiv847054649 div.MsoNormal
{margin:0in;margin-bottom:.0001pt;font-size:12.0pt;font-family:"Times New Roman";}
#yiv847054649 a:link, #yiv847054649 span.MsoHyperlink
{color:blue;text-decoration:underline;}
#yiv847054649 a:visited, #yiv847054649 span.MsoHyperlinkFollowed
{color:purple;text-decoration:underline;}
#yiv847054649 span.EmailStyle17
{font-family:Arial;color:windowtext;}
_filtered #yiv847054649 {margin:1.0in 1.25in 1.0in 1.25in;}
#yiv847054649 div.Section1
{}
-->
</style>
<div><font size="2" face="Arial">Allan,</font></div>
<div><font size="2" face="Arial">In most of California (seismic zone 4) residential
PV systems with solar arrays weighing less than 4 lb/ft2 do not require
structural engineering if the roof has one layer of composition shingles. The
reasoning is that roofs are allowed 2 layers of shingles (old set and re-roof
set) and a layer of shingles weighs 4 lb/ft2 so 1 shingle layer and 1 solar
array weighing less than 4 lb/ft2 is within the dead weight load limit. Hope
this helps.</font></div>
<div><font size="2" face="Arial">Joel Davidson</font></div>
<blockquote style="border-left: 2px solid rgb(0, 0, 0); padding-left: 5px; padding-right: 0px; margin-left: 5px; margin-right: 0px;">
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none;">----- Original Message ----- </div>
<div style="background: rgb(228, 228, 228) none repeat scroll 0% 0%; font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;"><b>From:</b>
<a rel="nofollow" title="allan@positiveenergysolar.com" ymailto="mailto:allan@positiveenergysolar.com" target="_blank" href="/mc/compose?to=allan@positiveenergysolar.com">Allan Sindelar</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none;"><b>To:</b> <a rel="nofollow" title="re-wrenches@lists.re-wrenches.org" ymailto="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" href="/mc/compose?to=re-wrenches@lists.re-wrenches.org">'RE-wrenches'</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none;"><b>Sent:</b> Tuesday, July 07, 2009 5:26
PM</div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal; -x-system-font: none;"><b>Subject:</b> [RE-wrenches] Roof Loading
request for help</div>
<div><br></div>
<div class="Section1">
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;">Wrenches,</span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;">We are currently facing a city
permitting bureaucracy that has recently discovered solar – that is, suddenly
each department in the permitting and plan review departments is coming up
with standards for PV systems. Some of the standards, of course, make no
sense. </span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;"> </span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;">PV systems typically add about
three pounds per square foot to the loading on a roof. We are facing a city
requirement for structural engineering work for standard roof
attachment if the mounting approach is to make penetrations into the roof
structure. This is a typical requirement that will only add considerable cost
to each PV system, and we’re looking to have our ammunition to fight this well
stocked in advance. Specifically, are building authorities in other
jurisdictions requiring structural engineering work for this type of
roof attachment?</span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;"> </span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;">Thanks
</span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;">Allan</span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;"> </span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">Allan Sindelar</span></font></p>
<p class="MsoNormal"><font size="2" face="Times New Roman"><span style="font-size: 10pt;"><a rel="nofollow" ymailto="mailto:Allan@positiveenergysolar.com" target="_blank" href="/mc/compose?to=Allan@positiveenergysolar.com">Allan@positiveenergysolar.com</a></span></font></p>
<p class="MsoNormal"><font size="2" face="Times New Roman"><span style="font-size: 10pt;">NABCEP Certified Photovoltaic
Installer</span></font></p>
<p class="MsoNormal"><font size="2" face="Times New Roman"><span style="font-size: 10pt;">EE98J Journeyman
Electrician</span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">Positive Energy, Inc.</span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">3201 Calle Marie</span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">Santa
Fe</span></font> , New Mexico
87507</p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">505 424-1112</span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span style="font-family: Arial; font-size: 10pt;"><a rel="nofollow" target="_blank" href="http://www.positiveenergysolar.com">www.positiveenergysolar.com</a></span></font></p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;"> </span></font></p></div>
<p>
</p><hr>
<p></p>_______________________________________________<br>List sponsored by
Home Power magazine<br><br>List Address:
RE-wrenches@lists.re-wrenches.org<br><br>Options &
settings:<br>http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org<br><br>List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org<br><br>List
rules & etiquette:<br>www.re-wrenches.org/etiquette.htm<br><br>Check out
participant
bios:<br>www.members.re-wrenches.org<br><br></blockquote></div><br>-----Inline Attachment Follows-----<br><br><div class="plainMail">_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address: <a ymailto="mailto:RE-wrenches@lists.re-wrenches.org" href="/mc/compose?to=RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Options & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br>www.re-wrenches.org/etiquette.htm<br><br>Check out participant bios:<br>www.members.re-wrenches.org<br><br></div></blockquote></td></tr></table>