Opinion » Letters

We've got a foam fan here



The article on the foam construction projects being promoted by Cal Poly architect Laura Joines is interesting stuff (“The house of next Tuesday,” Sept. 9). I was especially intrigued by the idea of being able to create non-linear shapes with computer interface. This frees up a lot of time if you want to produce structures that aren’t your basic rectilinear box.

I have been a fan of foam construction for quite a few years, but not the (more or less) conventional variety covered in the article, and not just foam with reinforcing rods either. For anyone interested enough to look, there is another foam core building type that is most commonly built by Monolithic Domes—but not limited to that company. These structures are built by first building a concrete foundation pad and then inflating a very large and complex plastic balloon with a high volume air pump on top of it. (These balloons are custom made for the desired shape, usually a dome.) Once the balloon is up, workers can enter through a passageway sewn into the base to spray liquid foam onto the interior surface of the flexible form. Once the foam has “set up,” a rebar reinforcing cage is fastened to the inside against the foam and secured with wire ties embedded in the foam. After everything has hardened, workers again enter the structure and spray gunnite (waterproof cement), which is hand surfaced before it hardens into concrete.

If desired, the builders can actually stop at this point, since the resulting structure is already extremely strong and waterproof. However, an additional layer of gunnite is customarily applied to the outer surface, which creates an essentially fireproof, earthquake-proof, and windproof building unmatched by any other building type known. An added benefit is that it takes almost no energy to heat. Construction costs for these homes are roughly the same as for conventional “stick built,” depending upon where it is built and who builds it.

This type of building also lends itself well to underground or partial earth-sheltered placement, which adds even more environmentally attractive possibilities to the earth-conscious home builder. About the only drawback to this type of construction is a general lack of knowledge and understanding on the part of many building departments—and a perceived lower resale value on the part of some real estate people and lending institutions (a result of the first two problems).

I keep hoping that someone will put one of these structures up with the other innovative structure in Poly Canyon, just to see what people’s reactions are. Here’s hoping.

Add a comment