Question - I am considering building a 3,000-square-foot "snap together" insulating foam block house. It must be economically priced and super-strong to resist tornadoes. Is this construction method efficient? - L.K.
Answer - There are several new construction methods, including the snap together blocks, that use a combination of rigid foam insulation and concrete. All of these methods produce a super-efficient house with utility bills 50 percent less than most similar-size houses.
All are also extremely strong. Some even survived a direct hit by Hurricane Andrew in otherwise destroyed neighborhoods. From indoors and outdoors, they look identical to any conventionally-built house.
The simplicity of building with snap together foam blocks is ideal for the do-it-yourself builder/ helper. Interlocking hollow rigid foam blocks are designed to literally snap together like a huge Lego house. The insulation value of foam blocks is as high as R-32.
The hollow foam insulation blocks snap together to form the foundation and walls. Openings for windows and doors are easily cut into the foam. The entire assembly is then reinforced with steel rods in the hollow cavities.
Using a pump truck, concrete is poured into the cavities at the top of the walls. The concrete flows throughout all the cavities and forms a solid strong monolithic insulated concrete wall. With the foam on the interior and exterior surfaces, the walls can be finished by any common method.
Each foam block (often made of expanded polystyrene) is roughly one foot square by 40 inches long and costs from $4 to $5. A block weighs less than four pounds and the blocks for an entire house weigh only several hundred pounds.
In addition to low-energy usage, strength, and termite resistance, these houses are quiet. The combination of the heavy concrete mass in the center, foam on both sides, and no air leakage, stops most outdoor noise.
A similar type of construction uses larger hollow foam panels that are made of a mixture of 14 percent concrete and 86 percent foam beads. This concrete/foam mixture is still lightweight, about 180 pounds per 10-foot wall section.
Another method uses sheathing backed foam wall panels. Concrete is poured onto the foam panels at your building site. When cured, the complete panels are tilted up on the foundation. Still another method uses steel mesh on the outside of foam panels. Concrete is blown on the panels at your site.
Write to me for Utility Bill Update No. 818 listing 17 manufacturers of foam/concrete houses blocks and panels, construction method details, insulation levels, block sizes, materials, and prices. Please include $2 and a self-addressed envelope. Write to James Dulley, Deseret News, 6906 Royalgreen Drive, Cincinnati, OH 45244
Question - I need to buy a new electric range and I was considering a self-cleaning oven. Does it use much electricity during the self-cleaning cycle? -- G.C.
Answer - A self-cleaning cycle can use a substantial amount of electricity. This is used to reach and maintain the high oven temperature to break down spills and spots.
Overall, a self-cleaning oven can be more efficient than a standard one. These ovens have thicker wall insulation to maintain a safe exterior temperature during the hot self-clean cycle. If you bake a lot, this heavier insulation saves more electricity than is used when self-cleaning.