[Greenbuilding] Exterior insulation retrofit

[JOHN SALMEN]

Problem with cladding on wood windows is the condensation that occurs
between the cladding and the wood - especially true for aluminum cladding.
Rot was a problem which led manufacturers to treat the interior wood with a
fungicide/preservative. The other problem with wood is stability for opening
windows. To be structurally stable wood has to be either a solid premium old
growth product (pine, fir, hemlock, cedar) or built up of components of
those materials to make them structurally strong. Warpage and movement can
still be a problem leading to leaky seals.

I think fibreglass is a better option (despite the fact that I own a
millwork shop) as it uses less material to better effect. If you want or
need the look of wood then I use it in small amounts for sill or liner and
casings (where you can use less threatened species - maples, alders, etc.)

Lots of fibreglass manuf. out there now with r5 windows (triple glaze).
Venting windows (operable) should be casement type and kept small to
minimize leakage. Biggest problem remains in the installation of windows as
they have to float in an otherwise rigid assembly so you need a proper
layering of gaskets and seals to allow movement and prevent infiltration. If
they are too rigidly installed they tend to deflect with building movement
and break seals (allowing infiltration). 



-----Original Message-----
From: greenbuilding-bounces at lists.bioenergylists.org
[mailto:greenbuilding-bounces at lists.bioenergylists.org] On Behalf Of
bill.allen at verizon.net
Sent: May-06-11 10:52 AM
To: Green Building
Subject: Re: [Greenbuilding] Exterior insulation retrofit

All,
Thanks for your comments on this thread.  The one thing no one commented on
was the windows.  Do folks have experience with R5 windows?  Can you
recommend any mfg's?  I am thinking Marvin Ultimate clad (wood with aluminum
cladding on the outside) but they cost an arm and a leg, even more so with
triple glazing to reach R5. Alternatives?
Thanks,
Bill
-----Original Message-----
From: Sam Ewbank <g.l.ewbank at gmail.com>
Sender: greenbuilding-bounces at lists.bioenergylists.org
Date: Fri, 29 Apr 2011 09:32:02 
To: Green Building<greenbuilding at lists.bioenergylists.org>
Reply-to: Green Building <greenbuilding at lists.bioenergylists.org>
Subject: Re: [Greenbuilding] Exterior insulation retrofit

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