A Solid Choice
Precast concrete basement walls
save time and money and result in dry basements
that meet the government’s new IRC building
codes.
By Bridget McCrea
When looking for a new home,
nearly everyone’s first concern is how
much square footage they can get for their buck.
One good way to make the space stretch with
little additional cost is with a finished basement.
The problem is that, among home buyers, the
word “basement” usually conjures
up images of damp, dark spaces that hardly rank
as good living and playing spaces. But the good
news is that precast concrete foundation systems,
designed for use in residential and commercial
construction, can eliminate those concerns.
For the architects, engineers
and contractors at Savannah Green, a large residential
development in Normal, Ill., precast concrete
basement walls were a natural choice. The neighborhood
combines affordability with high quality and
comprises 369 single- and multi-family homes
on a 76-acre infill site.
“We know the first thing
people will ask is how much home they’re
getting, and how much more they can get by finishing
the basement,” says Rick Allender, vice
president at CDG-Architects, Engineers and Planners
in Springfield, Ill. Allender points to the
precast basement walls – which don’t
crack or leak like their cast-in-place counterparts
– as an easy solution.
“Homeowners can turn
a 1,200-square-foot starter home into 2,400
square feet of living space without having to
worry about basement cracks or leakage,”
says Allender. The project’s builders
also benefit because the basement walls meet
the new International Residential Codes (IRC)
for energy efficiency and include a 15-year
warranty against defects or problems.
CDG, which handles individual
site plans and engineering for about 500 homes
a year, uses precast concrete systems on every
foundation it builds, according to Allender.
“We’ve even incorporated them into
commercial projects and custom homes,”
he says, adding that the biggest advantage over
a poured foundation is that precast walls don’t
shrink after being installed in the ground.
“If you were to pour
a continuous foundation, you’d end up
with shrinkage cracks – and that means
leaks,” says Allender. “The precast
walls are broken up into 8-foot-high by 16-foot-wide
panels that shrink while they’re in their
forms at the plant, in a controlled environment.
That means no cracks and no leaks.”
Precast concrete basement
walls can be insulated and pre-studded for easy
finishing, which is yet another benefit. They’re
also sealed with specialized concrete sealer,
says Allender, and require just one day or less
to install, compared to the several days or
weeks that a cast-in-place basement requires.
Combined, those advantages result in significant
cost savings on each house built.
“When you factor
everything in – and take into consideration
the cost of water-proofing the outside of a
traditional foundation, which is unnecessary
with most precast products – the savings
really add up,” says Allender. “I’d
say we come out a couple of thousand dollars
ahead on each home.”
Flexibility Counts
Five years ago, Nick
Capranica, president and COO of Construx of
Illinois Inc. in Springfield, Ill., was staring
at a stack of contracts for 50 new homes that
his company couldn’t deliver fast enough,
thanks to inclement weather. “It was cold
and raining, so we couldn’t get the foundations
poured,” recalls Capranica, who is both
the builder and developer on the Savannah Green
project.
Capranica solved the problem
by switching from cast-in-place basements to
precast concrete basements – a move that
he calls “one of the best things to ever
happen” to his company. “We went
from building 50 homes a year to building more
than 400 last year,” Capranica explains.
“We use them on our apartments, all of
our multi-family units, single-family homes
and light commercial projects.”
When it came time to develop
the Savannah Green community, Capranica says
there was little doubt in his mind that precast
basement walls would be his substrate of choice
for the homes. Within the development, lots
range from 40 to 50 feet wide, which puts the
homes in close proximity to one another and
makes pouring in place a real chore. “It’s
congested in there with a home every 50 feet
on center,” he explains. “Because
we’re using precast walls, we can just
dig one after another and set two houses per
day with no problem at all.”
Capranica, who has been using
wall systems manufactured by Superior Walls
of Central Illinois for the last five years,
says the raw costs are comparative to cast-in-place
foundations, with one major exception: Factor
in soft costs like time spent on the project,
the customer service callbacks that come when
the basements leak, and the ease of being able
to add an egress window or walk-out basement,
and there is no comparison.
“Our callbacks have
been cut by 90 percent because of our switch,”
says Capranica. “Plus, we have the added
flexibility of being able to make a change when
we sell a home – as the walls are being
fabricated. They’re very versatile and
have performed very well for us.”
Allender calls that flexibility
and versatility the most significant advantage
of using precast concrete walls on a project
like Savannah Green. The walls prove especially
useful in areas where the soil is bad and in
need of digging and replacement. They also came
in handy recently when a slight elevation error
was made on the project.
“One foundation was
put in at an elevation that just wouldn’t
work with the grades around it,” Allender
explains. “We were able to pull the walls
out, set them off to the side, (dig some more)
and set those walls back in place. With a cast-in-place
system, that would have been impossible.”
From the builder’s standpoint,
Capranica says the precast walls’ sole
limitation is that they require any decks be
built before any backfilling can take place.
“With a precast basement wall, the deck
has to go on first, which means you’re
sometimes working over an open ditch about 2
feet deep,” says Capranica. “That
can create a safety hazard, but we’ve
overcome the issue by building ramps that span
the ditch. We use them until the deck is built,
then haul them over to the next house.”
More Than Meets the
Eye
The advantages of using
precast concrete basement walls go beyond staying
dry and creating more space for homeowners.
The walls also meet stringent new building codes
set forth by the government. During the October
2002 Code Conference in Fort Worth, Texas, for
example, a joint resolution was reached to consolidate
the three model building codes (BOCA, SBCCI
and ICBO) under the International Code Council.
According to Aaron Schoeneberger,
marketing director for Superior Walls in New
Holland, Pa., the emphasis in the recently published
IRC is energy efficiency. So far, 43 states
have adopted all or a portion of the 2003 code,
which requires that basements be insulated during
the construction of the home. The “R-value”
required for each home is calculated based on
the EPA’s climatic zones.
“Our walls are provided
with R-5 insulation and equipped with built-in
stud cavities and furring strips for adding
more insulation,” says Schoeneberger.
“This means that a Superior Walls basement
may easily be finished up to R-24 with no additional
framing.”
This year, Superior Walls
introduced a new wall system, Superior Walls
Xi, which meets the Energy Conservation Code
requirements (IECC, IRC Chapter 11), with no
additional insulation. Schoeneberger says the
cornerstone of Superior Walls’ products
is not simply the precast concrete, but the
manufacturing process that the company uses
regarding insulation.
“Our products come pre-insulated,
and that insulation is bonded to the concrete,”
says Schoeneberger. “It’s also the
speed with which our walls are manufactured
in a factory-controlled environment, thus ensuring
there are no cracks before they’re panelized
and bolted together. They’re sealed with
a specialized concrete sealer and ready to be
installed in a much shorter time period than
a cast-in-place basement.”
The walls are also environmentally
friendly, or “green,” says Kale
Walker, president of Superior Walls of Central
Illinois. While the typical poured foundation
requires about 60 yards of concrete, a precast
basement uses only about 18 yards, thus conserving
materials and reducing the mess and waste on
the job site. Spillage can be kept to a minimum
because the walls arrive preassembled and ready
for installation, he adds.
Because it’s insulated,
the wall system itself is also energy efficient,
unlike a typical concrete foundation, which
“has no insulation in it and no insulating
value,” says Walker, adding that Superior
Walls’ products include 1 inch of built-in
Styrofoam, which gives them an R-5 energy value
and also acts as a thermal break. “Where
normally in a basement you might get a lot of
dampness and moisture because of condensation,
with the built-in insulation in the wall you
don’t have condensation problems, thanks
to the thermal break.”
The Only Choice
When Rich and Bert Hurst
sat down three years ago to build a new home
for their family that would one day be converted
into a bed and breakfast establishment, one
of the first choices they made was precast concrete
for their basement structure. Well-versed in
the home building process, the Hursts co-own
Hurst Brothers Development Co. in Ephrata, Pa.,
and say the precast walls were a shoo-in for
their new abode.
“We’ve always
found that the precast walls produce the driest
basement you can find,” says Bert Hurst.
“Choosing them for our new home was an
easy choice.”
Weaver Precast of Ephrata,
Pa., manufactured, delivered and installed the
walls. Rick Miller, vice president of sales
and marketing for the precaster, says the size
of the home presented a few design challenges,
mainly because it required a cut-up, detailed
foundation that encompassed 229 lineal feet
of 10-foot-high walls. “They wanted additional
space in the basement, so they went with the
higher wall height,” says Miller.
The home’s basement
included 20 corners and 27 panels that took
the precaster one day plus two hours the following
day to complete. A cast-in-place basement would
have taken at least five days to finish, says
Miller. Along with the time savings, the Hursts’
choice of precast walls also puts their new
home in compliance with the new IRC codes –
a factor that Weaver says has increased customers’
interest in precast concrete foundation systems.
“Demand for the walls
is increasing every year,” says Weaver,
who estimates that sales of the walls have grown
15 percent to 20 percent over the last five
years. He adds that a lot of code changes are
being implemented that make precast concrete
a much more favorable choice over cast-in-place.
The Hursts, who have
lived in their home for about three years now,
say they’re just pleased that the basement
has remained dry and that the installation met
their expectations. “The basement is just
immaculate,” says Hurst. “It worked
out very well, and we’re pleased with
our choice.”
Project Profiles
Savannah
Green
Project:
DND Traditional
Neighborhood
Architectural/Engineering
Company: CDG-AE
Inc., Springfield, Ill.
Builder/Developer:
Construx
of Illinois Inc., Springfield, Ill.
Precast
Company:
Superior Walls of Central Illinois,
Springfield, Ill.
Hurst House
Bed & Breakfast
Project:
Residence and
future bed and breakfast
Project
Owner: Rich
and Bert Hurst
Precast
Company:
Weaver Precast, Ephrata, Pa.
