Question - I am planning to build an energy-efficient house, and I am considering using a permanent wood foundation instead of concrete. Are there really any advantages to using a permanent wood foundation? - F. G.
Answer - As long as the soil type at your building site is acceptable, a permanent wood foundation (PWF) is an excellent choice. More than 300,000 houses in the U.S. and Canada have been built using PWF's.
PWF's are ideal for crawl spaces, partial and full basements. A finished PWF basement is as dry and warm as the typical living room. An entire panelized PWF can be installed by a small crew in just one day.
A PWF is basically a heavy-duty wood framed wall used for the foundation below the ground. It uses CCA pressure-treated lumber to resist damage from moisture and insects. If built to proper design specifications, it should hold up as well as a poured concrete or block foundation.
A PWF offers many advantages including lower utility bills, reduced construction time, construction in any weather conditions (even freezing) and potentially lower costs for a finished basement.
Since a PWF is just a framed wall, it can be insulated simply with batt insulation like any above-grade wall. With 2x6 framing, R-19 insulation is attainable. The wood walls are compliant to handle slight ground movements.
This high level of insulation can significantly reduce the utility bills and improve comfort in an otherwise energy-efficient house. There are special cement-like coatings for any exposed above-ground foundation lumber to give it a real concrete look and surface protection.
Several companies produce complete panelized PWF's. Send your blueprints to the company and their engineers design the PWF. The insulated panels are built in a factory and delivered directly to your building site.
Woodmaster produces a panel-ized PWF with a 75-year warranty against fungal and insect damage. For a leakproof foundation, shiplap joints are used instead of butt joints and all joints are sealed with waterproof adhesives.
Several panelized house kit manufacturers offer PWF options. If you plan to do some of the construction work yourself to lower costs, these house kits (up to 3,000 sq. ft.) are an efficient, cost effective option.
For finished basement construction, the electrical wiring and plumbing can easily be run through the insulated walls. Drywall or paneling is nailed directly to the studs without additional framing or furring strips.
Write for Update Bulletin No. 815 listing manufacturers of complete PWF frame panels and other special construction materials, a soil conditions chart, PWF design detail sketches and floor plans of several PWF/house kits. Please include $2.00 and a business-size SASE. Write to James Dulley, Deseret News, 6906 Royalgreen Dr., Cincinnati, OH 45244.
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ADDITIONAL INFORMATION
Some panelized house kits include a PWF
Factory made PWF panels assemble quickly at site
Pressure treated studs and plywood
2x4 or 2x6 stud wall with batt insulation
Drainage tiles and gravel at base