History --

History -- In the 1960's, the idea of foundations made of wood for light frame buildings seemed a bit farfetched. We were not used to thinking of wood products exposed to the weather as having a useful enough service life to be used as foundation material where a long life expectancy is prerequisite. However, there are many examples of wood all around us that are used for structural purposes that have lasted over 100 years. Wood piles have been used for over a century to support skyscrapers and bridges, marine pilings for piers and docks, railroad ties and bridge timbers; and in colonial times virgin timbers were used as the foundations for homes, churches and other structures. The use of wood for wood foundations is a good proven idea whose time has come.
In 1937 a research study was begun, initiated by the Forest Products Laboratory, to explore the utility of a wood foundation for a house. A creosote-treated timber foundation was built in Madison, Wisconsin. (Creosote in not an acceptable preservative for residential uses today, but back then, that was the most used preservative with an excellent track record). This building has given good service to date and is still being used as an office structure. Approximately 15 years after it was built it was moved, foundation and all, to its present site. The move presented an excellent opportunity to observe the condition of the treated wood foundation after a period of time in actual use. No degrading because of decay or insect attack of the treated wood was noted. The foundation performed as expected and still is.

In Canada in 1961, the National Home Builders Association, in cooperation with the Central Mortgage and Housing Corporation, built a crawl space type wood foundation, designated the Mark III; and in 1964 built a full basement wood foundation, designated the Mark IV. Both houses were built at the R.C.A.F. Station, Rockcliffe, Ottawa, Ontario. Both wood foundation walls were built with 2 x 4 studs with an outside skin of ½" T&G plywood. The wood in the Mark III foundation was pressure treated with 8 lbs. / cu. ft. with creosote, and the Mark IV with pentachlorophenol. The Mark III walls are on a footing of light concrete; and the Mark IV walls rest on a 2 x 8 footing which in turn rests directly of the bearing soil. The Mark IV has an untreated wood floor made of 2 x 8 floor joists nailed to studs and resting on a center bearing pony wall. These foundations are performing well and became the basis for the Permanent Wood Foundation System as we know it today.

In 1965 the American Wood Preservers Institute, the National Forest Products Association (now the American Forest & Paper Association), and the Marketing and Economic Division of the United States Forest Service approached the National Association of Home Builders Research Foundation to do a feasibility study on the wood foundation concept. After extensive research and development, the All Weather Wood Foundation emerged. It is now known under a new name: The Permanent Wood Foundation System.

Since 1969 specially treated wood (lumber and plywood) has been used commercially in the United States for wood foundations in light frame buildings such as homes, office buildings, churches, shopping centers, apartment buildings, and condominiums. That year, three houses were built in Lexington Park, Maryland by builder Jack Clifford. The foundation components were pre-manufactured by Kingsbury Homes, Division of Boise-Cascade. A block foundation was also constructed on a nearby site, using the same tradesmen, for comparison purposes. The idea was that if a true cost comparison was to made, the same tradesmen would have to be used.

At the outset, one of the many advantages of the PWFS became apparent. The block foundation had been scheduled to be built first, but in March 1969 the site was too wet and muddy. Under these conditions it was easier to move lumber and plywood than to move blocks and concrete, so the PWF's were built first. It was also learned that rain did not stop work on the PWF's, but did cause some delays in completing the block foundation.

In the same year Hurricane Camille drenched the area with 12" of rain in 24 hours. All three PWF's remained dry while the block basement and many other conventional basements in the area leaked or were flooded.

The National Association of Home Builders Research Foundation continues to monitor these original PWF's houses for horizontal and vertical movement, leakage and humidity levels, and any evidence of decay or insect attack. To date no problems have been found in these original wood foundations.

In 1971 the first PWF was built in Ohio for the Columbus Parade of Homes at Reynoldsburg, Ohio. The house was a tri-level and was built by Ernest G. Fritschie Company. At the same time Fritschie built a conventional house with a block foundation. It began 3 ½ days before the PWF, but both foundations were completed the same afternoon. If both had started at the same time, by the time the block foundation had been completed, the PWF house could have been completely framed.

In 1973 the first house in Michigan was built with a PWF in Leroy Township, Calhoun County by Brooks Realty. This was a ranch "double-wide" pre-manufactured home which was craned onto the PWF. This house was the only one in the subdivision with a full basement. It was located between a lake and a swamp with a very high water table. It had a 7' backfill. This home has been occupied since 1973 and has never had moisture problems even though it was originally built about 18" below the water table. The lower level basement area is used as a dry comfortable living space. In this case it doubled the livable portion of the home without adding to its cost. With its adopted aggregate drainage system, high water tables and other horrible site conditions need not be a deterrent to the successful installation of a PWF.

In 1980 Roscoe Clark of PWF, Inc. Flint, MI started designing foundations for builders and home owners for a low cost fee. This design service made the wood foundation easy to install.. Now you can have your next wood foundation custom designed and get training on how to install it. (PWF, Inc. can be contacted by your lumber dealer for more design information.)

Hundreds of thousands of wood foundations have been built in The United States, and when Canada is included, they number more than a million.

Advantages - The advantages of the PWF are numerous. Some of them are listed as follows:
A. Dry & Comfortable - PWF's create a completely dry comfortable living space below finished grade with no musty odors or smells. The basement is just like any room in the home above grade.
B. More Area in Basement - The walls are generally thinner with existing stud spaces ready for insulation, and with no need to add furring and losing area in the basement. Sometimes the area saved, if it could be concentrated in one spot would equal the size of a bathroom or even an extra small bedroom.
C. Warmer & More Energy Efficient - Because of the existing stud spaces for insulation
and because wood itself adds insulation value, the PWF saves heat loss and conserves energy, lowering heating and cooling costs. By contrast conventional foundations are good conductors of heat.
D. Strength & Stability - It is a common misconception that the kind of material determines the strength of the structure. Strength is determined by engineering and PWF's are engineered, and are as strong as any other material used for foundations. Wood foundations are engineered to as strong are they need to be. From a stability standpoint they are superior. Each wall of a PWF is like a truss (a stressed skin a plywood on a series of studs and plates). Unforecast weak spots in the bearing soil are simply bridged with no settling or cracking. Concrete does not bridge weak spots well.