<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html><head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head>Yes. As in you install R20 and get R18. <br/><p>Sent wirelessly from my BlackBerry device on the Bell network.</p><hr/><div><b>From: </b> Reuben Deumling <9watts@gmail.com>
</div><div><b>Date: </b>Fri, 29 Apr 2011 10:00:51 -0700</div><div><b>To: </b><jfstraube@gmail.com>; Green Building<greenbuilding@lists.bioenergylists.org></div><div><b>Subject: </b>Re: [Greenbuilding] Exterior insulation retrofit</div><div><br/></div><br><br><div class="gmail_quote">On Fri, Apr 29, 2011 at 9:58 AM, John Straube <span dir="ltr"><<a href="mailto:jfstraube@gmail.com">jfstraube@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Relatively small impact if you limit the connections to the minimum. We lose about 3% with screws doing foam and maybe up to 10% with thin plywood webs. Just add an inch if you care.<br></blockquote><div>10% relative to what? An ideal wall that has no plywood gussets? <br>
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