Foam Homes -- Polystyrene-And-Plywood Sandwiches
Can Make A New House Sturdier Comfier And Snugger
Bill Kossen
Seattle Times Staff: Seattle Times News Services
Terry Kirkpatrick is proud to live in a foam house. It
feels strong, looks good and has become somewhat of a tourist
attraction.
Just the other day, a group of about 20 building contractors
from Japan dropped by to visit his unique three-story waterfront
house on Lake Sammamish.
There they heard him describe the virtues of a house constructed
using structural insulated panels, or SIPs (basically compressed
styrofoam in a plywood sandwich). Panel houses, he said,
are easier to build, affordable, use less wood and are quieter
and more airtight than a traditional stick house.
"My heating bill in May was only $21.81," said
Kirkpatrick, who despite his apparent waterfront-affording
affluence, must make ends meet on a middle-school counselor's
salary. He can afford to live on the lake because the property
has been in his family since the 1940s.
But what Kirkpatrick seems to like best is the feel of
his house. He used 6-inch-thick panels on the exterior walls
and 8-inch-thick panels on the ceilings and floors.
"It's not going anywhere," he said with a smile.
Other "panelized" houses and buildings are starting
to pop up around the Northwest and across the nation. They
include:
-- The new headquarters office in Issaquah for Shirey Contracting,
which built Kirkpatrick's house and others in the area.
-- The 22-unit Emerald Courte apartments in Puyallup is
using SIPs manufactured by Fife-based Premier Building Systems.
Their panels also are going into a number of other new buildings,
including the new Boy Scouts headquarters in Tacoma, said
Premier's Kevin Hayes.
-- On Whidbey Island, architect Jean Steinbrecher specializes
in designing log houses with panel roofs, a popular use
because they can be quickly installed and thus protect the
rest of the house from rainy weather.
-- In Michigan, a new 200-house development is making news
by offering buyers a choice of either traditional stick
or SIPs construction.
Orchard View Estates is being built by Crosswinds Communities,
known for helping revive inner-city neighborhoods by building
new condos that resemble row houses. This Crosswinds project,
however, looks like conventional subdivision houses out
in a country location.
The two types of houses look the same from the outside.
The big difference is inside the walls.
Viewed from the top or bottom, these walls look like a
sandwich. The center of each is four inches of white foam
- extruded polystyrene. It's enclosed between two sheets
of heavy exterior-grade plywood.
The sheets are built from thin layers of shaved wood, bonded
together with glue. It looks like the typical processed
wood you might see on any house that doesn't yet have siding,
but it's actually thicker and stronger. A single wall panel
can be up to 8 feet high and 24 feet long.
With SIP houses, much of the labor takes place in the factory,
where each wall is custom-built for each house, and window
and door holes can be cut in.
When the walls reach the home site, they are glued and
nailed together. Either at the factory or at the home site,
tunnels are drilled through the foam plastic core to let
electricians and plumbers install wiring and plumbing.
SIPs get high ratings from the National Association of
Home Builders and the energy-conscious magazine Environmental
Building News, which last year devoted a cover story to
them.
Carpenter Jeff Wilson, who is working in the Orchard View
project, likes the look of houses built with SIPs. Sighting
down a wall's long, straight line, he says, walls usually
aren't like this in new houses today. They tend to bow in
or out.
"In the old houses, with plaster, you'd get that straight
look," said Wilson, but today it's usually missing.
"Our lumber isn't the way it used to be."
The consensus is that SIPs do a very good job of meeting
a house's basic needs. They give:
-- A higher level of insulation than the usual fiberglass
batting.
-- An air-leak seal with fewer seams than house wrap.
-- A structure that's two times as sturdy as conventional
2-by-4 stick building.
They do this at an affordable cost. And SIP houses go together
quickly, with less labor in the field - a boon given today's
shortage of skilled house framers.
Energy-conscious groups love SIPs. Even the thinnest SIP
wall - 4 1/2 inches thick - has a robust insulation value
of R15.
And many people like SIPs because they can be built with
recycled wood or young scrub trees, lessening demand for
old-growth lumber.
To its promoters, SIPs have a bright future because they
address many of today's concerns.
"Skilled labor is disappearing," said Donna Bade
Shirey, co-owner of Shirey Contracting. "Saving natural
resources in construction, not depleting our forests, energy-efficient
homes are all vital issues."
And as Wilson put it: "Being carpenters, we go through
a forest in a year. I like these things. I like to save
as many trees as possible."
Seattle Times staff reporter Bill Kossen and the Detroit
Free Press contributed to this report.
----- Q & A -----
Q: Aren't these houses too airtight?
A: It's much better to build a very airtight house, then
add a little inexpensive ventilation, than to struggle with
a leaky house.
Q: Aren't we damaging the ozone
layer when we manufacturer that extruded white foam?
A: No, 95 percent of SIPs are made with extruded polystyrene
(EPS), which does not have ozone-damaging by-products. If
you encounter the rare SIP that says it's made with HCFCs,
avoid it. Its manufacture does damage ozone.
Q: Doesn't the extruded foam make
a good home for carpenter ants?
A: It would, so many SIP makers include an insecticide.
The R-Control brand infuses its foam with a relative of
the boric acid that many people sprinkle to kill ants. It
is harmless to humans.
Q: Doesn't all that glue in the
wood panels give off gases that can hurt chemically sensitive
people?
A: It could if the glue is formaldehyde-based, so the consumer
should check. Some SIP makers use formaldehyde glue on the
exterior panel and a different glue inside. Others use only
a water-based glue. Once the water dries, what's left is
an inert plastic.
- Detroit Free Press
|
