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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'>I think for most codes the requirement is ½ hr fire rating. Untreated ply sheathing doesn’t do it – you can get the rating with ¼” roof board. SIPS would either have ½” drywall attached or attached to the particle board. I think for most building departments its a learning curve – they tend to ignore what they don’t see – but ignoring it makes them liable.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> Greenbuilding [mailto:greenbuilding-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Steve Houlihan<br><b>Sent:</b> December-07-14 10:29 AM<br><b>To:</b> greenbuilding@lists.bioenergylists.org<br><b>Subject:</b> Re: [Greenbuilding] Polyiso strength on roof<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>There are many thousands of roofs out there with a layer of plywood then rigid foam above. I'm under one right now. I have never seen the Building Department to have a problem with this. I suggest you check with your local jurisdiction to be sure.<br>I don't see any difference to this from using SIPS on the roof.<br><br>Steve Houlihan<o:p></o:p></p><div><p class=MsoNormal>On 12/7/14 10:08 AM, John Salmen wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Ply sheating wouldn’t qualify as a barrier. Glas mat roofing board would.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> </span><o:p></o:p></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Greenbuilding [<a href="mailto:greenbuilding-bounces@lists.bioenergylists.org">mailto:greenbuilding-bounces@lists.bioenergylists.org</a>] <b>On Behalf Of </b>Alan Abrams<br><b>Sent:</b> December-07-14 9:55 AM<br><b>To:</b> Green Building<br><b>Subject:</b> Re: [Greenbuilding] Polyiso strength on roof</span><o:p></o:p></p></div><p class=MsoNormal> <o:p></o:p></p><div><p class=MsoNormal>'nuther factor is the prohibition against exposed plastic foam in the attic. even foil faced polyiso does not fulfill the requirement.<o:p></o:p></p><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal>-aa<o:p></o:p></p></div><div><p class=MsoNormal><br clear=all><o:p></o:p></p><div><div><div><p class=MsoNormal><span style='color:#660000'>Alan Abrams<b><br></b></span><i><span style='color:#666666'>certified professional building designer, AIBD<br>certified passive house consultant, PHIUS</span></i><o:p></o:p></p><div><p class=MsoNormal><i><span style='color:#666666'>certified passive house builder, PHIUS<br></span></i><span style='font-size:7.5pt;color:#666666'>cell 202-437-8583<br><a href="mailto:alan@abramsdesignbuild.com" target="_blank"><span style='color:#666666'>alan@abramsdesignbuild.com</span></a><br></span><a href="http://www.heliconworks.com/index2.html" target="_blank">HELICON WORKS <i>Achitecture and Education</i></a><o:p></o:p></p></div></div></div></div><p class=MsoNormal> <o:p></o:p></p><div><p class=MsoNormal>On Sun, Dec 7, 2014 at 12:44 PM, Ron Cascio <<a href="mailto:roncascio@verizon.net" target="_blank">roncascio@verizon.net</a>> wrote:<o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#1F497D'>Sounds good to me.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#1F497D'>Ron</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Greenbuilding [mailto:<a href="mailto:greenbuilding-bounces@lists.bioenergylists.org" target="_blank">greenbuilding-bounces@lists.bioenergylists.org</a>] <b>On Behalf Of </b>Bill Allen<br><b>Sent:</b> Sunday, December 07, 2014 10:52 AM<br><b>To:</b> Green Building<br><b>Subject:</b> [Greenbuilding] Polyiso strength on roof</span><o:p></o:p></p></div></div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US> </span><o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>Hi all</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>I am about to reroof my 1926 colonial and am looking to also insulate per the BSC "deep energy retrofit" plans consisting of plywood sheathing, 2 layers of 2" polyiso, another layer of plywood, then roofing (in my case, standing seam metal roofing).</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>The original roof was wooden shingles that are still in place with 2 layers of asphalt on top. Also still in place are the nailers for the wood shingles...roughly 1x2s, 5.5" on center across the rafters.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>My question is: if I leave the 1x2 nailers in place during the demo can i exclude the first layer of plywood and install the polyiso directly on the nailers? It would then have plywood on top, secured with long screws into the rafters. Less material and less cost.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>Thanks for any thoughts/comments.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US> </span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US> </span><o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>Sent from my cell phone</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>< dy></span><o:p></o:p></p></div></div><p class=MsoNormal><br>_______________________________________________<br>Greenbuilding mailing list<br>to Send a Message to the list, use the email address<br><a href="mailto:Greenbuilding@bioenergylists.org" target="_blank">Greenbuilding@bioenergylists.org</a><br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br><a href="http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org</a><o:p></o:p></p></div><p class=MsoNormal> <o:p></o:p></p></div></div><p class=MsoNormal><br><br><br><o:p></o:p></p><pre>_______________________________________________<o:p></o:p></pre><pre>Greenbuilding mailing list<o:p></o:p></pre><pre>to Send a Message to the list, use the email address<o:p></o:p></pre><pre><a href="mailto:Greenbuilding@bioenergylists.org">Greenbuilding@bioenergylists.org</a><o:p></o:p></pre><pre><o:p> </o:p></pre><pre>to UNSUBSCRIBE or Change your List Settings use the web page<o:p></o:p></pre><pre><a href="http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org">http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org</a><o:p></o:p></pre></blockquote><p class=MsoNormal><o:p> </o:p></p></div></body></html>