I just inspected a house that has treated wood foundation.
I would love to here any comments on how they perform or how long they are supposed to last. My client is very confused on whether to buy it.
Personally I am not thrilled with them and I don’t think anyone builds them anymore, and there is probably a reason for that.
Each wood basement should be an engineered product and, if they are designed and built properly, are a good product. The back fill is especially important. They are, typically, warmer and easier to finish than masonry basements and go up faster, too.
In Canada, a PWF does not have to be engineered unless it goes outside the CSA standard *(CAN/CSA-S406, Construction of Preserved Wood Foundations.) *recognized by our codes…similar to regular codes…go outside the limits of the code (say studs at 25+" inches OC) and you’ll have to get a civil engineer involved. If they’re bult according to instructions in average conditions, there should be no problems.
I have worked on or built 10-12 PWF’s. The last one in 2000 was an interesting job. Got called in the winter of 1999 by one of my former employees from my old home town about 150 miles away. He owned an 1880’s Victorian style house with 18 corners and a partial stone foundation. His family was growing, he ran business from his house, he wanted more space, hence the desire for a full basement. He hired me for a week to design/supervise the job. Visited him in February, he’s happy as a pig in … with the product.
I’m usually referred by other inspectors here when called to inspect a PWF. The last one I did last summer was not built according to the book. Within 1/2 hour of starting the inspection I told the young couple (first time buyers), this is going to cost you $40-50+ grand!!! The foundation was bowing inward as much as 4-5 inches from being under-framed and being backfilled with regular, heavy clay. The young lady sat down on a bed and cried!! The house was nestled in a rural wooded setting and her heart was set on it.
Don’t inspect it unless you have worked on them and know the downfalls!!!
My opinion: PWF’s are mostly given a bad rap. The Install makes all the difference in the world, unfortunately you cant dig it up to see it. Humidity/mold becomes a larger problem, but can be managed with proper knowledge. Life expectancy is approx 100 years with a proper install.