A log home, with a classic western design, was situated in a quiet neighborhood near Sun Valley, Idaho, until February 2009 when it was completely destroyed by fire. Luckily, no one was home at the time, but everything the homeowners owned was suddenly gone. The source of the fire was determined to be within the main fuse panel.
Take a minute to look around your house—at all your memories, everything you own, and imagine never seeing any of it again.
Catastrophic as it was, good insurance coverage allowed for rebuilding, even though nothing remained of the old structure except the front door. But what to build?
Because of what happened, abandoning log construction in favor of concrete seemed the logical choice. An architect and contractor were commissioned to start work with the owner on a new contemporary design. The fireproof concept included a one-story, eco-friendly, low-maintenance, natural-lit, and space-efficient design.
Due to budget constraints, structural insulated panels (SIPs) were chosen for all exterior walls and the roof. SIPs accelerated the speed of construction because the panels are fabricated in a factory and greatly increase the energy efficiency of the house compared to standard wood frame construction. The design also included cast-in-place shear walls to separate each bedroom for strength, sound deadening, winter heat-banking, summer cooling, and additional fire security. The intent was to leave these walls exposed to add architectural interest.
The owner wanted creative concrete work throughout the house. Cliffhangers Inc., Hailey, Idaho—a 40-year decorative concrete firm—was contracted. Construction on the 4000-square-foot home started in August 2009 and was completed in September 2010. The result is tasteful concrete features at its best.
Interior and exterior wall panels
Cliffhangers set up a large slate-texture skin casting bed onsite to make 1/2-inch-thick exterior panels and a sawed-travertine stone mat with minimal texture for casting the inside panels. The concrete mix included polymer, a high dosage of microfibers, and a polycarboxylate superplastizer to add strength and keep the water-cement ratio low. The architect used the panel edges to add architectural interest; each panel was formed and cast to fit its specific location—rather than cast and then cut to fit. As a result, almost no concrete was wasted.
The home’s exterior integrally colored panels featured a light brown cast. To make them, workers bulkheaded the size for each panel on top of the texture skin, casting one at a time. Cliffhangers took a belt-and-suspenders approach by securing each panel to walls using thinset cement and screws at each corner—patching screw holes afterward. As a precaution, vapor barriers were installed over the SIPs and a void was created to allow moisture accumulations to drain away.
The interior panels were made using white portland cement and a small amount of integral color to provide a cream-buff coloration. Attempts to remove bug holes during the casting operation weren’t made because they added to the look. As was the case with exterior panels, interior panel perimeter lines were used to add architectural interest; the largest panel cast spanned 8x8 feet.
Family room centerpiece area
One shear-wall defines part of the family room, featuring a set of wood steps attached only to the wall, causing no small amount of headache for the builder. The free-standing steps had no other method of support. Behind the steps, patterned panels change in appearance as the angle of lighting changes, or by your location of viewing. This wall captures your attention when you enter the family room.
Partially stamped floors
All the floors feature radiant heating from a geothermal heat pump, with the coils embedded in 3-inch-thick integrally colored concrete over plywood, which covers a crawl space under the floor. The contractor installed construction joints covered by ¾-inch-wide steel accent strips to reduce the possibility of cracks and provide architectural interest.
As the concrete stiffened, workers stamped slate textures into the surface and then troweled approximately 50% of the impression flat to provide a unique appearance. This technique helped make the floor easy to clean and maintain. Water-based acrylic color highlighting improved the overall appearance. Afterward, 4x8-foot 1/8-inch-thick mat board sheets were placed over the work and taped together to prevent damage from other trades.
All the counters were cast-in-place. The edges for the counters along the walls were 2 inches thick while those for the island countertop were 5 inches thick. Overall, the fiber reinforced concrete was 11/4 inch thick. The island was diamond polished to an 800-grit finish and sealed with polyaspartic polyurea sealer to prevent food stains, acids, and damage from hot kitchen utensils.
An unusual wall panel above the stove showing fish swimming was precast with broken, crushed glass bottles to define the fish images.
Bathroom sinks and counters
The five bathrooms each include concrete counters and sinks, offering another opportunity for creative expression. The 3-foot-long 14-inch-wide 6-inch-deep sink in the master bathroom was molded with expanded foam. The counters were diamond polished and some were acid etch stained to provide additional color over the integral coloring.
Concrete shower stalls
Concrete shower stalls in the Sun Valley area are popular and were included in every bathroom of this house. Most were simply a continuation of the interior wall panels that carried through the shower areas but one polished shower features a free-standing 11/2-inch-thick wall. A system of bug holes and recycled glass in the panels made the walls of this particular shower stand out.
The adjoining two-story garage was constructed with ICF walls and a structural concrete ceiling/floor. The large upstairs bonus room features an office, exercise equipment, a steam bath, and space for children to play. Again, exterior and some interior walls are clad with precast concrete panels.
Stamped patios and driveway
Each bedroom opens to an outside patio area, all featuring cast-in-place integrally colored and stamped with 2- to 5-foot-diameter random stone patterning. Acid etch stains highlighted the impressions afterward.
Architectural shear walls
Cast-in-place shear walls were included in the design for three reasons: to provide structural support for the roof, to add soundproofing between bedrooms, and for architectural effect. A small amount of integral color was added to the concrete to provide a warmer look.
Formed with higher than usual grade sheeting materials, the walls feature clean concrete surfaces. More attention was paid to internal vibration to reduce the amount of bug holes as well, however, the cone-shaped form-tie holes were left to add to the appearance.
Cliffhangers is known for high-quality glass-fiber reinforced concrete (GFRC) rockwork and it is featured in this construction. A 7x21-foot GFRC waterfall forms one side of the patio area in front of the family room and is a viewable backdrop from inside the house.
In the living room space, a wood furnace provides maximum thermal efficiency—an arm load of firewood lasts all day. Portions of the furnace are shrouded with GFRC, carrying the waterfall theme indoors.
Perhaps the most creative use of GFRC, however, is the 20x25-foot, low-profile landscape rock located between the house and a stream that flows nearby. This “toprock” outcrop is cast into a base slab to minimize movement and there are several soil pockets for plants to grow.
You might think that concrete doors are a bit over the top but concrete offers creative opportunities not possible with wood. The original front door of the house was built with concrete panels, the only part of the house to survive the fire, and remains the front door of the house. The door is heavy and as you might imagine, swings open and closes slowly but smoothly. Cliffhangers decided to include panels for inside doors because of the creative possibilities. The 3/8-inch-thick and fiber-reinforced door panels showcase unique patterns with recycled glass made from broken bottles glued onto the forms. Afterward, diamond polishing the panels revealed the glass. When lights are on in the bedrooms or the hallway, the illuminated crushed glass reveals the patterns—one child bedroom door panel has a biplane pattern. The estimated total weight of these doors is about 100 pounds.
Why so much concrete?
Above all else, the owners wanted a fire-safe home. Concrete met this requirement and provided the perfect opportunity to explore its other benefits. The home is responsibly built, energy efficient, easy on the environment, and environmentally safe to live in. Its minimal maintenance needs will continue to benefit the environment.
The challenge for concrete is learning how to use it. When the criticism is made that concrete is over-used on a project, it may be the result of too little creativity. This home features decorative concrete everywhere. About 80% of all the surfaces in the home are concrete, but you hardly notice it because of its creative use. You are welcomed by a warm, inviting feeling when you enter and your eyes begin to explore all the special features.
The question shouldn’t be why so much concrete, rather, why not?
Architect: Brunelle Architects, Hailey, Idaho, www.brunellearchitects.com
Engineer: Liv Jensen PE, Hailey, Idaho, firstname.lastname@example.org
General Contractor: Lee Gilman Builders, Ketchum, Idaho, www.leegilman.com
SIPs: Precision Panel, Eagle, Idaho
Concrete Contractor: Cliffhangers Inc., Hailey, Idaho, email@example.com
Special Forms: Thomas Schrunk, Artist, Minneapolis, www.thomasschrunk.com
Ready-Mix Producer: Idaho Concrete, Ketchum, Idaho