ICF
101
ICF 101 Here is
an introduction to insulating concrete forms for
contractors seeking the basics of this construction
application.
By Joseph Lyman
In
the past decade, scientists have claimed that rising
temperatures and warmer-than-average winters are proof
that North America is feeling the effects of global
warming. Just don¹t tell that to the millions of North
Americans who experienced one of the coldest and most
brutal winters in recent history. From ice storms
in Tennessee and North Caroline to massive snowstorms
in the Rockies, Midwest and Northeast, it was a frigid
and severe winter for almost everyone in North America.
However,
more than 100,000-plus insulating concrete form homeowners
throughout North America experienced a different winter
behind the comforts of their ICF walls.
Advancements
in technology and innovation, as well as customer
loyalty, have rapidly propelled ICFs into a residential
market phenomenon. The above-grade residential market
for ICFs increased from 1.0 percent in 1998 to 2.7
percent in 2001, according to the national association
of Home Builders. Additionally, the Insulating Concrete
Form Association and Portland Cement Association predict
ICFs will account for more than 8.0 percent of the
above-grade residential market by 2005. With energy
legislation currently before Congress providing tax
credits to contractors that build energy-efficient
homes, the ICF market share is poised to make significant
gains in the coming years.
The
concept
ICFs are insulated forms for poured concrete walls
that stay in place as a permanent part of the wall
assembly. The forms, made of foam insulation, are
either preformed interlocking blocks or separate panels
connected with plastic or metal ties. The left-in-place
forms not only provide a continuous insulation and
sound barrier, but also backing for drywall on the
inside, and stucco, lap siding, or brick on the outside.
Although
all ICFs are identical in principle, the various brands
differ widely in details of their shapes, cavities
and component parts. Block systems have the smallest
individual units, ranging from 8 inches by 1 foot
4 inches (height times length) to 1 foot 4 inches
by 4 feet. A typical ICF block is 10 inches on overall
width, with a 6-inch cavity for the concrete. The
units are factory-molded with special interlocking
edges that allow them to fit together much like plastic
children¹s blocks.
Panel
systems have the largest units, ranging from roughly
1 foot by 8 feet to 4 feet by 12 feet. Their foam
edges are flat, and interconnection requires attachment
of a separate connector or ³tie.² Panels are assembled
into units before setting in place either on-site
or by the local distributor prior to delivery.
Plank
systems are similar to panel systems, but generally
use smaller faces of foam, ranging in height form
8 to 12 inches and in width from 4 to 8 feet. The
major difference between planks and panels is assembly.
The foam planks are outfitted with ties as part of
the setting sequence, rather than being pre-assembled
into units.
Within
these broad categories of ICFs, individual brands
vary in their cavity design. ³Flat wall² systems yield
a continuous thickness of concrete, like a conventional
poured wall. ³Grid wall² systems have a waffle pattern
where the concrete is thicker at some points than
others. ³Post and beam² systems have widely spaced
horizontal and vertical columns of concrete, which
are completely encapsulated in foam. Whatever the
differences among ICF brands, all major ICF systems
are engineer designed, code accepted and field proven.
The
ICF experience
Market
share and benefits related to ICF homes only tell
a small portion of what motivates people to purchase
an ICF home. The ICF story is a mixture of customer
loyalty and brand identity that surpasses the benefits
of living in an energy-efficient, disaster-resistant
structure. Ask most people what comes to mind when
they think of living in a concrete home, and they
say ³cold,² ³drab,² and ³prison-like.²
Compare
that with the comments of those living in an ICF home
and there¹s a sharp contrast. ICF homeowners boast
about their comfort level, the love of their home,
how much they save on their energy bill and how they
would never live in any home but an ICF. Asked recently
about his ICF home, John Ware, of Denver, says, ³I
built an ICF home for my family in 1999 and have enjoyed
the benefits for more than four years. I cannot imagine
living in an ordinary house ever again.
So,
what¹s behind the rapid increase in market share?
As I speak with ICF homeowners throughout North America,
it never ceases to amaze me how closely they identify
with living in and owning an ICF home. They also give
high marks for energy-efficiency, quality, comfort
and rock-solid performance.
The
general contractor
Equally
important in the success of a well-built ICF is how
it is installed. The proper consolidation of concrete
in an ICF can make the difference between an extremely
durable, energy-efficient home and something that
should be targeted for the local dump. Since the placement
of concrete is the most important component of the
ICF construction process, contractors must take extra
care to do their homework on the ICF installer. Currently,
there are many resources for hiring experienced ICF
crews. The Insulating Concrete Form Association lists
those who can install ICFs for general contractors.
Additionally, the ICFA has a joint training program
with the United Brotherhood of Carpenters, which many
UBC apprentices and journeymen have successfully completed.
John
Vogstrom of Vogue Homes, of Twin Cities, Minn., has
been working with the ICFs for the past five years.
³I
have extreme confidence in the ICF system,² he says.
³With advancements over the past several years, it
really is a well thought-out building system.²
As
for the strength of the market, Vogstrom says that
demand is high. He began participating in the local
Parade of Homes in 2001 and has found it to be the
best venue to demonstrate firsthand the benefits associated
with ICFs.
³Before the 2001 Parade of Homes I was building approximately
10 percent concrete homes but I am now building 95
percent ICF homes and project that virtually all of
my future building will be with ICFs,² he adds.
The
finishing contractor
ICFs
are one of the most versatile building systems available,
and virtually any type of exterior finishing system
can be used. One of the best and most reliable for
ICFs is acrylic finish. Over the past several years,
a great deal of finishing contractors have been turning
to ICFs because of its solid substrate, limiting the
risks of failure associated with other types of building
systems.
Calvin
Ladd of Titan Walls, located in Twin Cities, Minn.,
has been installing acrylic finishing systems for
the past 10 years, and he now prefers working exclusively
with ICFs.
³ICF
and acrylic finishing systems absolutely creates the
most beautiful exterior available,² explains Ladd.
³It is simple to adhere, less labor intensive and
can be installed in sections without complicating
the project.²
Vogstorm
agrees, adding, ³ICFs and acrylic finishing systems
are a perfect mach.²
As
for the education and experience required for installing
acrylic finishing systems on ICFs, it is relatively
small.
³For
experienced finishing contractors, the learning curve
is relatively small,² Ladd says. ³Since I had experience
working with other types of building systems such
as wood and steel, ICFs were fairly easy to learn
how to finish.²
To
share ideas and teach others, Ladd routinely participates
in a local education seminar sponsored by Cemstone,
a ready-mix concrete company located in the Twin Cities
area that offers ICFs and concrete services to customers.
The ICFA represents the ICF industry and is a first
step in gathering additional information concerning
ICF projects. The ICFA offers contractors several
different publications on the ICF construction process,
and the ICFA Web site (www.forms.org) is filled with
information about ICF systems, as well as ICFA member
listings. Additionally, the Portland Cement association
(www.concretehomes.com) is also another source of
useful information.
The
Insulating concrete Form association is the business
association of the insulating concrete form industry.
Courtesy
of Walls & Ceilings