They may sound like something Fred Flintstone would use to build his house, but Styrofoam-concrete blocks can create foundations that work better in some ways than concrete alone, according to Anaheim-based CTS-Conform.
ConForm units, as the blocks are called, increase strength, insulate against heat and cold and noise, and shape easily to create pleasant curves, says Mariola Kasprzak, president of CTS-ConForm.
For the guy building the house, ConForm promises even more benefits. He can finish the foundation in a single day, doesn't need a factory full of power tools to work the expanded polystyrene material, and because 30 pounds of ConForm does the work of 500 pounds of concrete block, he can lug the stuff to the top of Mt. Everest without causing a hernia.
"It's going to knock the socks off the foundation people if they don't get into it," claims Mike Solbach, a builder in Georgetown, Calif.
Solbach believes ConForm has a future similar to that of PVC pipe, which took time for builders to accept but eventually became the most popular material used for plumbing.
A growing national market for the ConForm system seems to support Solbach's enthusiasm, although penetrating the building industry is a formidable task.
All other things being equal, Al Koeller, president of Koeller Development in Huntington Beach, says builders will go with the system they know best.
"It's bucking the usual construction industry problem--why change something that's been done one way since they built the pyramids?" says Koeller, who has done three projects using ConForm.
ConForm is actually a non-structural form for foundations and walls that is not removed once concrete is poured into its cavities. As a result, the properties of the expanded polystyrene are added to the strength characteristics of the concrete.
Reinforced with the appropriate rebar, ConForm has the structural integrity required for retaining walls, commercial and residential buildings, swimming pools and stem wall foundations. The material can replace concrete blocks, poured-in-place concrete or tilt-up concrete.
Adapted to U.S. building codes from a European design by English architect David Horobin, the product received the approval of the International Council of Building Officials, an important step for broader acceptance of the product, in late 1988.
The cost of the ConForm material runs about $1.78 a square foot, compared with about $1.20 for concrete. Builders make up the added cost by saving on labor.
Since the standard ConForm unit is a 40-inch block with 10-inch cavities and weighs only 1 1/2 pounds, Solbach has developed a clip system that allows builders to set the blocks quickly and firmly before pouring the concrete. Once the first course is in place, interlocking teeth keep the blocks plumb and straight during assembly.
A builder can cut the ConForm with a handsaw. The outside of the blocks are scored at 2-inch intervals and the insides of the blocks are pre-marked to describe the most common radii builders might want to use for curving walls.
With the blocks in place, concrete is poured in 5-foot lifts that require only an hour of curing before the next lift can be poured.
Using ConForm, the house foundation is automatically insulated and the floor itself doesn't require insulation. This also overcomes the problems associated with traditional insulation getting wet during the building process.
There are standard adhesives and coatings that stick to the polystyrene and dry to create a hard surface.
Solbach built a ConForm wall to support his hillside workshop, and he uses the wall for experiments with new coatings. Once it is coated with an appropriate material, the ConForm beneath is undetectable. If you ram your car into it or wail away with a hammer you can dent the polystyrene, but if the surface is damaged it is easily patched.
Ultraviolet rays will cause oxidation of the material, and the company recommends coating it within six weeks, but the residue can be brushed off. And for those concerned about the environmental impact of the material, CTS-ConForm says its product contains no ozone-busting chlorofluorocarbons.