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Concrete Homes Newsletter
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Concrete Homes Newsletter > 2006 > July/August
July/August 2006
Masonry Home Wins Design "Showdown"
It lies low on the hillside, like a gunslinger in an old Western—flat
on his belly peering over the scrubby ridge down to Tucson. Surrounded
by the looming column-and-arms of the saguaro cactus of Old West iconography,
you half expect to stumble across a bleached cattle skull.
Instead, there is the structure which the designers wanted—in its
design and execution—to appear to grow out of the steep hillside
without disturbing the fragile landscape. Concrete block, prominent
inside and out, was a large part of achieving that aim—a material that
supported the structure on its hillside perch and tied the home aesthetically
to the
rough country outside.
“Masonry was the only choice for this project,” say the designers,
Luis Ibarra and Teresa Rosano. “We used masonry inside and out to blur
the distinction between desert and house, while mitigating sun exposure and
focusing the views.”
Both Rosano and Ibarra are Tucson natives. They pride themselves on their
deep understanding of the extreme conditions in the Arizona desert, an understanding
they put to work on the home that won the National Concrete Masonry Association’s
(NCMA) Residential Award of Excellence.
Contest juror Patrick Rand called the 2,150-square-foot Garcia Residence “beautiful,” and
lauded its “crisp geometry.” For the home, completed in 2001,
designers Ibarra and Rosano created “three terracing platforms” that
stepped up a hillside dotted with jojoba bushes, palo verde and saguaro.
These platforms, or bays, divided the house into three zones: “living” on
the lowest level, “circulating” on the central level, and “sleeping” on
the upper level.
“We used the middle bay, the entry ‘gallery,’ for both
circulation and as an extension of the living spaces,” according to
the designers. “It invites the visitor down to the living, dining and
kitchen spaces on the [north facing] lowest platform, while connecting the
house to the bedrooms on the [south facing] upper level.”
The living space pivots so the main window can capture a view of Tucson
and the Catalina Mountains. On the upper platform, the bedrooms are separated
by a courtyard, which allows exposure to the southern sun and provides a
view up the ridge.
“We wanted to do the least damage to the site as possible,” says
Rosano, principal architect for the firm, Ibarra Rosano Design Architects.
So the terraces are narrow to keep excavation and fill to a minimum – 14
feet 6 inches on the living level; 8 feet on the circulation level; and 14
feet on the sleeping level.
Relying on standard gray CMUs as the primary building material helped the
builders preserve the delicate environment around the home site, Rosano adds.
The blocks’ modularity allowed easy delivery by crane to the locations
where the material was needed. “The house was built from the inside,
so there didn’t need to be an outside swatch of land that had to be
used for staging,” she says.
The concrete block walls were reinforced by anchoring them directly into
the bedrock, just below the surface. “That hillside is largely solid
rock,” she says. “We did that rather than pull the rock out and
replace it with concrete.” Once the walls were up, they were sandblasted,
revealing the black and gray aggregates in the block.
The load-bearing walls were constructed using a post tension system in which
steel rods span the distance between the stem and the top of the wall. Cavities
in the block were filled with foam, providing insulation to the house. The
CMUs’ thermal mass is a plus for energy efficiency in a desert environment. “There’s
a 40-degree swing from day to night here. The thermal mass helps moderate
the temperature,” Rosano says.
With gray stone spread across the steep terrain, “the use of natural
gray block was not only economical, but visually correct in the landscape,” the
designers say. “While the gray color complements the gray-green jojoba
bush, rusted steel echoes the veins of iron oxide coloring found in the fieldstone.”
As the project was underway, the number of the home’s residents increased.
The client started out as a single man, Rosano says. “Partway through
construction, his girlfriend—now wife – came into the picture.
She loved the house.” One effect she had on the design was to get the
swimming pool, eliminated for budgetary reasons, restored. It was built at
the east end of the house.
Although the home uses standard gray CMU primarily, the design includes
other types of block that served specific purposes, and added subtle variations
to the minimalist design. “Different blocks with different uses have
a different aggregate mix,” Rosano explains. “So the 8-inch corner
blocks are a different mix from the blocks that are used around the lintels.
So it does add to the interest.” Juror Rand took note of this, writing, “The
cool massiveness of the concrete masonry walls is in contrast to the open
and warm-hued materials finishing the spaces.”
The secondary building materials—steel, birch and concrete—share
with concrete masonry the simple and durable qualities that complement
the desert environment. And while the home site is not quite as lonesome
as it
seems— there are other neighbors nearby, Rosano says – the Garcia
Residence’s three acres are surrounded on two sides
by protected land.
And on the hillside, the home lies low. Almost a piece of the desert itself.
Thanks to NCMA for this article.
ICFs Assist Habitat in Olympia, Washington
Three 2-story ICF homes are under construction in Olympia, Wash.
for the South Puget Sound affiliate of Habitat for Humanity. The homes
are part of a larger, 15-home development, all of which will be built with
ICFs. The homes will also feature HardiPlank fiber-cement siding, and the
parking areas will be of pervious concrete.
The first pump day occurred on May 10th. They were able to pour the walls
for the first floor of all 3 houses. The second story was completed about
45 days later.
The construction supervisor, Jerry Fugich, is very knowledgeable about the
project and is excited to be building sustainable, "Green Built" houses
that will be good for the community and the families.
The volunteer laborers were trained continuously on ICF installation, radiant
heat floors and many other green building ideas. The homes will primarily
be 2-story homes on a stem wall foundation, and range in size from 900-1,200
square feet.
The largest home, a 4-bedroom, will be a “Woman Built” home.
The Governor of Washington, Christine Gregoire, is scheduled to help construct
this house.
After the first three homes are complete, it is expected that six more will
be built in 2006, with the remaining six built in 2007.
This project is a combined effort of many companies, including Miles Sand & Gravel,
Logix ICF, James Hardie fiber-cement siding, Simpson Strong-Tie and Lafarge
North America.
For more information on this project, please call Lori Peterson at (206)
923-950 or Jerry at (360) 239-1035.
Precast Moves Into Milwaukee Neighborhood
After winning a design competition to redevelop an industrial corridor within
the city of Milwaukee, Vetter Denk Architects set out to give new life to
the area along the Milwaukee River known as the Beerline “B” neighborhood.
The redevelopment progressed through various phases and, in 2004, the company
embarked on the third phase of the project, the Park Terrace Row House development.
A major constraint of the atypical multi-family structure was that it was
to be built into the side of a hill, so the garage would be prominently featured
on the third floor of the structure. Because of this unique architectural
demand, the company decided the most viable option to complete the Park Terrace
Row House as intended was to use precast concrete products from Spancrete.
Precast products would be used for the garage floor, partition walls and
for the rear wall of the row houses, which required the creation of a retaining
wall.
“In lieu of filling a structural steel cage…, the use of precast
products made more sense,” said Brian Filkins, architect at Vetter
Denk. “In this business, time is money. Precast concrete enabled us
to meet the structural needs of the project and get it done in a timely and
efficient method.”
Also unique to the project are the interior walls. To stay true to the modern
urban loft-style of the dwelling, the Park Terrace Row House units
complement the exposed brick and wood beams with walls featuring exposed
precast concrete.
“It’s certainly not for everybody, but our clientele loves it!” said
Filkens.
Little Precast House on the Prairie
A new technique for making log homes replicates the look of wood logs so
well that it might fool termites—at least until they tried to bite
into one. The homes feature precast components that are cast and stained
to resemble wood logs, creating a design that offers great potential for
homes around the country, its makers say.
“We see a lot of people who don’t want to deal with the problems
created by wood logs,” says Tom Beaudette, principal in Beaudette Consulting
Engineers, which helped create the connection designs and schematics.
The concept has been developed by Cultured Log Systems in Missoula, Mont.,
which worked with Missoula Concrete Construction to create the system and
products. The precast homes were the brainstorm of Missoula Concrete’s
former owner, Dick Morgenstern, explains Doug Bauer, president. Morgenstern
saw pending problems with finding large enough logs to continue building
log homes in the region, where they were quite popular. In addition, wood
logs had significant drawbacks that he thought could be overcome with precast
concrete designs.
To create a template, Morgenstern cut down a tree in his own front yard
and used it to create a rubber mold. (“I don’t think his wife
has still forgiven him,” Bauer says.) From that, reverse impressions
were made to create a form liner for the precast logs. The panels created
from the design are 16 inches high, 8 inches wide and a maximum of 28 feet
long. That height can be formed into two 8-inch logs or other configurations
as well, Bauer notes. Three styles of logs currently are offered as standard
designs: a 16-inch-tall panel with a hand-hewed, squared-off look; a panel
with two 8-inch-tall, D-logs; and a 16-inch-tall panel with a squared-off
style Bauer calls the “back East look.” Each log also includes
an insulated core to improve energy efficiency.
Rebar connects the logs vertically, explains Stewart Hansen, president of
Cultured Log Systems. “The height that can be created is unlimited,” he
says. Most homes to date have been two stories, but four or five stories
are possible by simply using a wider foundation and slightly thicker logs
at the base, he notes.
A wide range of roof styles can be attached to the logs, Beaudette says. “We
can adapt the system to almost any type of roofing the homeowner desires.” Standard
connections are used throughout, making it an easy system to replicate,
he adds. “The homes use typical structural details that are normal
for any residential situation,” he says. “And the logs won’t
move around.”
Indeed, one key advantage the structures offer is that they won’t
shrink, settle or shift as log homes often do, Beaudette says. There
are other benefits to the precast design, too:
• The precast components arrive at the site ready to erect, unlike
wood-log packages that can require modifications at the job site. The precast
logs are cast to architectural specifications in advance, and the factory
casting of the pieces ensures openings are precise to window and door manufacturers’ specifications,
says Hansen.
• There is no need to re-stain or seal the logs annually, as there
often is with wood logs. This can save more than $750 per year in maintenance
costs.
• Precast concrete’s composition makes the logs fire resistant,
providing a three-hour fire rating. That durability produces a minimum of
a 20-percent reduction in insurance costs compared to comparable log or frame
homes, Hansen says.
• The homes are resistant to insects and decay, as well as mold and
fungus, due to their inorganic material. That saves further by alleviating
the need to prevent these problems.
• The precast mix can include recycled materials such as fly ash.
The thermal mass of the concrete helps to retain heated or cooled air, which
is aided by the interior insulation. That can produce savings of between
30 and 40 percent on heating and cooling costs, Hansen says.
In general, the precast log homes have lower material costs and also save
on erection labor. Typical labor on a log home costs $25-$35 per square foot,
Hansen estimates, which will cost a homeowner between $50,000 and $70,000
more for a 2,000-square-foot home. “This is a substantial savings in
anyone’s budget.”
The system has been well received in Montana, Hansen notes, and the process
is poised for expansion. “It’s a patented system, and we’ve
been waiting for that to be completed,” he explains. “So we’ve
been intentionally quiet until early last year.” Currently, the homes
are being shipped only to Montana and Idaho locations, Bauer notes. “But
we’ve had interest from down in Virginia, so there’s real potential
for expansion.”
The construction method and appearance continue to be refined, he adds. “This
is our laboratory out here. We’re still in the process of determining
how best to market the homes before we try to expand nationwide.” The
company hopes to license other precasters to sell the homes and cast the
logs. “It’s taking off so quickly that it’s apparent we
won’t be able to keep up with demand from one facility, and the shipping
costs from Montana would be prohibitive in some cases.”
“The full potential remains to be seen,” says Beaudette. “But
we do a lot of log and timber construction out here, and this new approach
is proving very popular. More and more, precast designs will take off
as word of mouth spreads and more structures are constructed. The homeowners
are telling others that these are thermally well insulated homes that
are
a structurally super-efficient design. You can’t tell the difference
between this and wood unless you get right up to it and pound on it.
The texture and color are very good."
Thanks to PCI for this article.
Concrete Technologies Tour: The Hot Ticket in Phoenix
This year's Concrete Technologies Tour, produced by the Concrete Home Building
Council (CHBC) of the National Association of Home Builders (NAHB) was held
in Phoenix, Ariz., June 11 - 13.
This is the second year that CHBC has produced this three-day event, which
attracted nearly 100 home builders and industry executives. Attendees networked
and learned about the latest developments in the use of concrete and cement
based products in residential construction.
Job site visits allowed attendees to see products and systems in use, while
visits to various manufacturing facilities demonstrated the efficiency and
high standards to which products in this industry are produced. Keynote speakers
and exhibit tables at breakfast and dinner provided additional learning opportunities.
Monday stops included Robson Ranch, an active adult subdivision,
in Casa Grande, featuring the construction of uniform thickness post-tensioned
foundations and post-tensioned masonry walls using the Integra System
by Superlight, an OldCastle Company. The next stop in Casa Grande was Trustone
America’s manufacturing facility, the first autoclave aerated plant
in the U.S. On-site demonstrations included placement and cutting
of the block and then the finale of day one was the production of the block.
Tuesday stops included: SW Architectural Castings, a precast plant; Eagle
Roofing Products; Superlite Block; Sunset Trails IV, an ICF subdivision,
and the tour concluded with a visit to Suncoast Post-Tension's new facility,
where attendees saw firsthand the extrusion and fabrication of bulk material.
"Virtually every home uses concrete," says Dawn Faull, program
manager for the CHBC, "but this tour represents a unique opportunity
for home builders around the county to learn about and experience uses and
applications for concrete and cement-based building materials that they may
not be aware of."
The 2007 Concrete Technologies Tour will be held in Minneapolis. For more
details on the 2006 or 2007 tour, please contact BSC at 800.368.5242 ext.
8676.
Thanks to CHBC for this article.
Faull Resigns as CHBC Manager
Effective June 28, 2006, Dawn Faull stepped down as program manager of the
Concrete Homebuilding Council. She was hired in 2004 and was the first to
hold that position, which was created shortly after the council was formed.
In her two-plus years with NAHB, she started the Concrete Technologies Tour,
managed CHBC’s trade show efforts at the NAHB Green Building Conference
and International Builders’ Show and helped coordinate the residential
concrete Mega-Demo at the 2006 World of Concrete.
In a brief statement, she said, “With some excitement and some regret,
I will be leaving NAHB and my position with CHBC. I will be moving back
to Phoenix, Ariz. to pursue another opportunity. I wanted to thank all
of you for the support you have given me and this new council, we couldn’t
have made this work without our members.”
Upcoming Events
• Concrete Foundations Association Summer Meeting
Wisconsin Dells, Wis., July 19-21, 2006 More
•
National Concrete Masonry Association Midyear Meeting
Victoria, British Columbia, July 26-30, 2006 More
•
Interlocking Concrete Pavement Institute Summer Meeting
Toronto, Ontario, August 23-26, 2006 More
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