https://wiki.opensourceecology.org/index.php?action=history&feed=atom&title=Non-Condensing_Roof_Insulation 2026-04-13T01:38:31Z Revision history for this page on the wiki MediaWiki 1.39.13 https://wiki.opensourceecology.org/index.php?title=Non-Condensing_Roof_Insulation&diff=310000&oldid=prev 2025-08-04T23:52:19Z

<p></p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 23:52, 4 August 2025</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>We need a total minimum R-value of R-49. Of those, at least R-15 must consist of air-impermeable rigid insulation.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>We need a total minimum R-value of R-49. Of those, at least R-15 must consist of air-impermeable rigid insulation.</div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">That means 2 layers of 2" [https://www.menards.com/main/building-materials/insulation/foam-board-insulation/r-8-laminated-expanded-polystyrene-2-x-4-x-8-foam-board-insulation/1632120/p-1444435971616-c-5779.htm]</ins></div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Technically, we&#039;re in zone 5A, but right on the border of zone 4A, so I&#039;m using 4A values: https://codes.iccsafe.org/content/IRC2021P3/chapter-8-roof-ceiling-construction#IRC2021P3_Pt03_Ch08_SecR806.5</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Technically, we&#039;re in zone 5A, but right on the border of zone 4A, so I&#039;m using 4A values: https://codes.iccsafe.org/content/IRC2021P3/chapter-8-roof-ceiling-construction#IRC2021P3_Pt03_Ch08_SecR806.5</div></td></tr> </table>

Marcin https://wiki.opensourceecology.org/index.php?title=Non-Condensing_Roof_Insulation&diff=309999&oldid=prev 2025-08-04T23:50:54Z

<p>Created page with &quot;We need a total minimum R-value of R-49. Of those, at least R-15 must consist of air-impermeable rigid insulation. Technically, we&#039;re in zone 5A, but right on the border of zone 4A, so I&#039;m using 4A values: https://codes.iccsafe.org/content/IRC2021P3/chapter-8-roof-ceiling-construction#IRC2021P3_Pt03_Ch08_SecR806.5&quot;</p> <p><b>New page</b></p><div>We need a total minimum R-value of R-49. Of those, at least R-15 must consist of air-impermeable rigid insulation.<br /> <br /> Technically, we&#039;re in zone 5A, but right on the border of zone 4A, so I&#039;m using 4A values: https://codes.iccsafe.org/content/IRC2021P3/chapter-8-roof-ceiling-construction#IRC2021P3_Pt03_Ch08_SecR806.5</div>

Marcin