Re: [GBlist] SIPS

[Sacie H Lambertson <dlambert@grasshoppernet.com>]

Based on the experience of building only two structures with SIPs I have
the following thoughts:

1.  No need to vent, but I would tape with Tyvek type every seam of the
roof.  Warm air can find its way up through these very small gaps and hit
the cold above and form water under that roof.  This is a very important
step.  (Make sure you tar paper/felt over OSB under the metal roof--both of
my buildings had metal roofs as well)
2.  Make sure any openings are thoroughly sealed--ie your pipes for the
solar panel.  Foam does a good job of this.
3.  4-1/2" thick is not R-30.  You will need something close to 10" of ESP
to get the R-40 you want.   EPS per inch is something over  R-4 I believe.
Don't believe your local supplier about the numbers.  Most of these are
exaggerated claims. 
4.  Check out the many manufacturers of SIPs, particularly R-Control.  They
can supply you a finished 4'x however long you need panel for a reasonable
price.  (They also will sell you the EPS alone).    I believe the company
'Riverbend' is another good one.  Any good company can help you design what
you want.  Find a the good one closest to you.  There is one company I
definitely would not recommend.
5.   Any panel manufacturer will have its own connection system and it is
much much easier to buy the panels cut for the spline connection rather
than try to do it yourself.  Basically you'll have to burn out the foam and
the stuff is really toxic.  There is not one good system for connecting
them.  I would prefer splines that are made partially of foam though--ie
not solid 2xs.
6. For the doors and windows, get a long blade for your saw-zaw and cut out
all the openings yourself.  You'll be much happier with the result than if
you get the panel manufacturer to do it.
7.  The way you want to build, ie placing the SIPs on top of a rafter
system is the best use of this type of construction material--ie SIPS are
ideal for a timberframe structure.
8.  Walls are the most common place SIPs are used.  I wouldn't pass this up.
9.  A caulk-type adhesive suitable for foam and OSB is what you want, or
use the foam adhesives---with a gun.  I have learned of this material only
in the last year or so and with the gun, which is a good investment, it
can't be beat.  Check out prices on the gun too; they vary a lot.
10.  Of course you can glue the drywall directly to your well-taped
ceiling.  The first SIP building I did (the panels were called something
different back then) had drywall on the interior and you can still buy them
this way.    It is not a structural panel of course but if you have a
timberframe type of application, this is definitely the way to go--saves a
lot of time and money.  All your ceiling drywall seams will be covered by
the glulams.  Just be sure to tape the panel seams.
		Sacie Lambertson
I too thought I would make my panels when I first read about the idea, but
quickly decided it better to buy them.   Got them from Winter Panel in
Vermont, one of the old firms (and still out there).  That was in 1986, and
no local person had a clue about EPS etc.
	It is a great system.  More expensive in material than stick framing but
potentially a lot tighter and very very quick to go up.

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