What would you think if a foundation contractor told you that he could install your foundation in less than two hours? You’d probably chalk it up to walking around too many job sites without a hard hat. But sometimes, seeing is believing. This certainly was the case when I went down to southeastern Pennsylvania to watch the installation of a Superior Wall foundation system. Superior Walls of America, Ltd. (P.O. Box 427, Ephrata, PA 17522; 800/452-9255), manufactures a prefabricated foundation system consisting of steel-reinforced insulated concrete panels that are trucked to the site and set in place with a crane.
I was trained as a mason, and I’ve laid tens of thousands of concrete blocks in conventional foundations. When I first heard of the system, I have to admit I was a bit skeptical. But after watching a Superior Wall foundation go in, I‘m convinced the company has a first-rate foundation system.
What’s in a Wall?
The panels consist of 2x8 concrete studs, sheathed with a 1-inch layer of extruded polystyrene insulation board and covered with an exterior face shell of 2-inch concrete. At the top and bottom of the panels, the concrete studs and face shell are connected by concrete "wall plates" that serve as bond beams. The panels are factory-cast using a 5,000-psi fiber-reinforced concrete, and are available in standard heights of 4, 8, and 10 feet in lengths up to 12 feet. The concrete studs are reinforced with a 3/8-inch vertical bar on the interior (tension) side of the wall, and each bond beam is reinforced with two 3/8-inch bars.
Site Preparation
A perimeter drain is placed a foot or so outside the foundation footprint, and 6 inches of 1/2-inch crushed stone is spread over the entire basement area and leveled.
Figure 1. In areas where the panels will sit, the gravel is compacted with a vibratory plate compactor, then accurately leveled using a magnesium straightedge.
