Concrete walls offer disaster protection

Dear Jim: We are planning our “dream” house. We want it to be stylish, but also energy-efficient and reasonably priced. With concerns about terrorism, its strength and airtightness are important. What do you suggest? – Jon M.

Dear Jon: One of the best house construction methods, considering your particular concerns about disasters, is stay-in-place-form concrete walls. These houses are not only super energy-efficient, but they are extremely strong. Even tornado or hurricane winds won’t blow one down.

Other than deeper window openings, these homes look like any other. Your architect will actually have more styling flexibility due to the strength. Interior and exterior walls can be finished with drywall, paneling, siding, brick or stucco.

I would recommend one of the foam block building methods. These are large, often 4-foot-long, hollow foam blocks. They are usually made of polystyrene insulating foam like a cooler. Once the blocks are stacked up to create the wall, concrete is pumped in the top to fill the hollow block cavities.

You can expect your utility bills to be about half those of a code stick-built house. This results from the high insulation level and the efficiency benefits of the high thermal mass of the concrete. The overall building cost is only about 3 percent to 5 percent more than a lumber stick-built house.

The first thing you notice when you enter one of these houses is how quiet it is. The heavy insulation and concrete mass inside the walls block outdoor noise. With the concrete core and tight sealing foam blocks, the homes are very airtight. This is an advantage for your terrorism concerns.

You have several choices of foam block designs. One type, called waffle, uses molded all-foam blocks with internal webs. This creates continuous cavities of various widths. If you would break away the foam insulation after the concrete sets, the concrete surface would resemble a waffle.

Another effective design is a flat wall. These blocks are made of flat sheets of foam insulation, usually about 2 inches thick. There are metal or plastic webs in between them to space them apart. When the concrete is poured in, it forms a core of constant thickness, often 6 to 12 inches.

The waffle-type blocks produce a higher overall insulation level because there is more foam. Also, less concrete volume is needed to fill the wall. Talk to builders to see which they prefer to use in your area. A third foam block design produces a post-and-beam concrete pattern inside the blocks.

There are also new foam floor-ceiling-roof insulating foam forms. Concrete is poured over them and in channels. They are very strong, efficient and quiet.

Write for (instantly download – www.dulley.com) Update Bulletin No. 746 – buyer’s guide of 18 concrete/foam block manufacturers listing sizes, foam type, insulation values, weights, prices, and descriptive details of various block designs. Include $3 and a business-size SASE, and send to James Dulley, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.