<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html><head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head>Rob,<br/><br/>Thanks for the references. Guess I have reading for bedtime tonight:-)<br/><br/>Might you be near Mt Vernon, NY?<br/><hr/><div><b>From: </b> Rob Dickinson <robd@pobox.com>
</div><div><b>Sender: </b> robddickinson@gmail.com
</div><div><b>Date: </b>Thu, 28 Apr 2011 09:10:45 -0700</div><div><b>To: </b><bill.allen@verizon.net>; Green Building<greenbuilding@lists.bioenergylists.org></div><div><b>Subject: </b>Re: [Greenbuilding] Exterior insulation retrofit</div><div><br/></div>Bill,<div><br></div><div>I'm working on the same type of project, and we're right in the thick of it.</div><div><br></div><div>I would recommend that you check out a paper that I believe <span class="Apple-style-span" style="font-family: arial, sans-serif; font-size: 13.2353px; border-collapse: collapse; ">John Straube recently put out (Feb 1) on high performance residential enclosures. It's very good and covers lots of practical details. It's a good follow-up to last years paper on high r-value wall assemblies. It covers lots of assemblies for ceilings, roofs, basements, etc., as well as air sealing details for electrical penetrations, venting, etc.</span></div>
<div><span class="Apple-style-span" style="font-family: arial, sans-serif; font-size: 13.2353px; border-collapse: collapse; "><div><br></div><div><a href="http://www.buildingscience.com/documents/reports/rr-1005-building-america-high-r-value-high-performance-residential-buildings-all-climate-zones/view" target="_blank" style="color: rgb(119, 153, 187); ">http://www.buildingscience.com/documents/reports/rr-1005-building-america-high-r-value-high-performance-residential-buildings-all-climate-zones/view</a></div>
<div><br></div></span></div><div>Also, for attaching the foam, there is good documentation on the proper technique and fastening specs on Green Building Advisor. One good article is at:</div><div><br></div><div><a href="http://www.greenbuildingadvisor.com/blogs/dept/musings/fastening-furring-strips-foam-sheathed-wall">http://www.greenbuildingadvisor.com/blogs/dept/musings/fastening-furring-strips-foam-sheathed-wall</a></div>
<div><br></div><div>They highly recommend the FasterMaster HeadLok screws, which is what I am going to use. This article gives the screw spacing specs for various thicknesses of foam, including 4". The HeadLok screws are available in pretty much all lengths, so they can accommodate whatever depth wall assembly you end up with. I needed to go with 8 1/2" screws to go through my furring strips, 4" of foam, my new Zip System sheathing, my old 1" lap siding, etc.</div>
<div><br></div><div>Green Building Advisor also has some videos on techniques for installing the foam. One detail I learned there, which probably ought to be obvious, is the way to stagger the two layers foam at corners to create a good air-seal there and not have a direct path to the inside/</div>
<div><br></div><div>On our project, we're re-sheathing the whole building with Zip System panels, which are OSB panels with a built-in water-resistive-barrier already on them. With the Zip panels we then use a special (Zip) seam tape to create a very air-tight assembly. So I am doing this prior to installing the foam.</div>
<div><br></div><div>We're also installing housewrap over the Zip boards to ensure water-tightness at window and door openings, but that might be overkill. Or it might be prudent, but it adds to the cost.</div><div><br>
</div><div>With the 4" of insulation, we've divided that into two layers of 2" foam. That way, we can tape the seams of both foam layers with the foil tape to try and increase the air-seal at the foam layer as well. We're also staggering the joints of the two foam layers.</div>
<div><br></div><div>Good luck. Please share what you learn.</div><div><br></div><div>Rob<br><div><br></div><div><br></div><div><br><div class="gmail_quote">On Thu, Apr 28, 2011 at 5:45 AM, <span dir="ltr"><<a href="mailto:bill.allen@verizon.net">bill.allen@verizon.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Hi all,<br>
<br>
I am researching a project for my single family home. Classic 1926 stick construction. Zero insulation in the walls...time yet again for an external paint job. Would really appreciate comments on the following plan:<br>
<br>
We never want to paint again...are thinking of natural cedar shingle siding, maybe with preservative but otherwise left natural. Don't like the embodied energy in the various cement siding solutions....alternatives?<br>
<br>
While the siding is down, fill the wall cavities with cellulous from the outside.<br>
<br>
Replace original double hung windows with new construction insulated, R-5 if we can afford it, windows mounted "innie" on the plane of the original dimensional 1x lumber t+g sheathing.<br>
<br>
Add external insulation....rigid styrofoam. Since there is no interior vapor barrier (plaster on wood lathe), I am worried about the dew point ending up in the center of the wall...therefore, per the building science article, add 4" of styrofoam to the outside to keep the dew point external of the sheathing.<br>
<br>
Will require careful details at windows and other penetrations.<br>
<br>
Big job...has anyone done this? Any comments on any part of the above would be most welcomed.<br>
<br>
Thanks,<br>
Bill<br>
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