[GBlist] re: SIP's

[Chris Koehn <chris@koehn.com>]

I've built around 60 homes with SIP's - primarily over timber frames. I seem
to have missed the message (I take the digest..) with a SIP question, but
I'll comment briefly on what Sacie wrote, which was generally great.

I work primarily with Insulspan out of Michigan. Their detail for roof
joints involves injecting a two part foam in to the joint. The thermal
testing I've seen on this is that unless you totally screw it up, it's hard
to get anything but a very thermally efficient, tight joint. We do go over
the joints on the outside with a gunnable roof tar- primarily to keep the
OSB edges from swelling if they get wet before roofing. Some others have
used strips of ice and water shield over the joints with good effect.

A 4 1/2" thick EPS core (core thickness is 3 5/8") panel offers R19. This
panel tests better than a 2X6 wall with any kind of insulation. We generally
use a 5 5/8" core panel, for an R 26 (walls) and a 9 3/8" core roof for R
42.

I have 9 3/8" core panels on the roof of my timber frame home/office. They
span from ridge to eve- a distance of 16'. Roof panels can be structural. No
need for timber- just a ridge beam of some sort.

Order the panels as pre-cut as you can get them- so long as the pre-cut
service is as good as Insulspan's you'll come out time and money ahead. I've
cut out many a window on the job, and unless you really enjoy the taste of
foam bits, it's not much fun. Of course, if you don't know where your
windows are going, cutting on site is an option. I can even get complete
structural valley systems from them. Install a few structural splines,
assemble, and presto.

I order panels as big as they will come. Insulspan makes them 8' X 24'. We
set mostly with a crane (or at least an AT forklift), and so a few of these
big guys covers a bunch of real estate in a hurry.

Insulspan (owned by the same folks who own Riverbend Timber Framing)
includes all spline material (2X for structural panels; OSB flat splines for
non-structural connections), all pre-cutting, all necessary sealants and
adhesives, and fasteners. Panels can be purchased as a commodity (raw panel-
you figure it out) but one of the most attractive things I find about them
is the ability to pre-engineer and pre-cut (and in some cases even
pre-assemble) them in a factory condition, thus speeding site time and
enclosure time. Getting out of the weather fast has a substantial value.

Any other questions don't hesitate to E mail me directly.

Chris


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