1st Wood Foundation

I have an upcoming inspection on a home that was built in 2009 and has a wood foundation. It has a complete basement. (Wisconsin) I don’t have any photos or other information.

This is my first wood foundation structure since I started in 2015. Any tips or information that I should know?

Thanks in advance.

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Wow… wood foundation on a 2009 build? That seems almost impossible. Could it be a typo on the listing? Or, do you have other info? I remember reading about wood foundations in my training book back in 2000 but don’t recall every seeing one.

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Not a Typo. They made it a point to let me know its a wood foundation. I don’t have any other info.

I’d probably try to chase down the relevant code book if there is one. I always remember seeing some alternate (rare but allowed) methods in the Oregon code book when I look at it. Honestly, I’ve never paid much attention since it’s never mattered… lol. Wondering if there’s some reason - like they couldn’t get a concrete truck up the driveway?

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Matt Fellman
mfellman
InterNACHI®️ CPI
2m
I’d probably try to chase down the relevant code book if there is one. I always remember seeing some alternate (rare but allowed) methods in the Oregon code book when I look at it. Honestly, I’ve never paid much attention since it’s never mattered… lol. Wondering if there’s some reason - like they couldn’t get a concrete truck up the driveway?

— Apparently there is an old timer that hung up his hat about 5 years ago. He refused to do concrete foundations. He built homes for 30 + years and they all have wood foundations.

@sbridges2 is on to something. From his provided link

Bottom of this page has the downloadable guide to PWF

http://www.southernpine.com/publications/

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PWF foundations are VERY common today. I inspect a few every year. They actually have very few problems when built properly.

Search this MB archives. I have posted many times about these and have included some videos of the building process.

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https://forum.nachi.org/search?q=PWF

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Interesting read… thanks. Guessing the reason I don’t see them in the Pac NW is that our soil pretty much sucks and drains poorly and those soil types are excluded (or must be approved by an engineer). Fwiw, I regularly see 100+ year old wood posts buried in soil in well-draining parts of town that are as sturdy as the day they were installed. Newer builds in the suburbs with sloppy wet clay? The posts would be rotted before the 12-month warranty was up.

PWF seem like a good candidate for the other area I inspect in Hawaii as the soil there drains great. However, they just do a lot of post/pier with no perimeter foundation. Regional differences in this biz are fascinating.

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Very popular here in Atlanta up until the 1940-1950’s. Then most were converted to crawlspaces with filler between piers. Then foundations with crawls took over, they typically suck.

Finally, very little new construction on crawls.

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80%+ of everything in Oregon is crawls from about the 60s on. Only reprieve is a house on a hill with a slab basement. At least we don’t have snakes in said crawls :slight_smile:

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Interesting, I’ve yet to see one here in SW Ohio.

If I had a choice I think I’d stick with the tried and true poured foundation.

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Rick; Try and find out who manufactured the wood foundation. Woodmaster from Prescott, WI was quite active, and now operates under a different name in Minneapolis. They engineered their work and provided a 75 year rot warranty. High quality foundation.

If builder fabricated, make sure to include a disclaimer. Builder fabricated often have build defects. The American Wood Council design book that JJ referenced is the reference that builders should use.

I know this is long, but I include this disclaimer with wood foundation inspections:

“The foundation consisted of a treated wood foundation. A properly built wood foundation consists of many components, including but not limited to soil type, drainage, soil depth against the foundation wall, structural support of the wall structure, along with many other components. In order to assure proper construction, a structural engineer should be involved with design of the foundation system. The majority of components were hidden from view. Because of these issues, the Inspector limits his inspection to only those observations that were visible at the time of the inspection. The Inspector did not evaluate structural components and hereby disclaims all liability for these components and for defects not visible at the time of the inspection.”

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Kind of a fascinating video for something I have not come across in WA. I love the old school nail banging vs. nail guns. A lost art!

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I personally worked on three homes in the late seventies that had wood basements. Two were typical tract type homes the other was a multimillion dollar home. Last I checked they were all still there.

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Rick,
Welcome to the world of home inspections. We have a couple sub divisions of homes build with wood foundations, most are on crawl spaces. The builder in Indiana moved out west after lawsuits, due to clay soils and back fill of foundations. The homes usually fall into two areas, POS and OK. The homes in Indiana have no ducting for HVAC. The crawl space is the plenum, with holes cut into sub floor for ventilation.
Keep the Faith,
John
Indianapolis

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In my area of Indiana there are not many homes with wood foundations. I probably have inspected a half dozen or so. The homes built on sandy soil I found no issues. Every one that was built on clay had experienced some degree of failure. The soil type and the type of water proofing applied to the exterior below grade sheathing are the two most important factors on whether the PWF will perform satisfactorily.

Two of the homes had experienced severe damage to the below grade wall assembly. One was caused by a leaky hose spigot (the hose spigot had been replaced the week before the inspection). This information was disclosed by the seller after all the damage was discovered later by the foundation contractor. Apparently the hose spigot was allowed to leak over a long period of time. The other home had damage to the PWF that was caused by a condensate line (air conditioner/condensing furnace) that drained near the foundation. Both these homes had finished basements so therefore none of the PWF was visible. The only sign of possible damage was in the basement the drywall at the top of the wall near the ceiling had experienced compression damage indicating settlement at this area. Basically the treated lumber bottom plate that rested upon the concrete footing had rotted and the whole wall assembly settled where the rot occurred. On the first home where I found the damage to the drywall, I wasn’t even going to mention it or put it in the report since the damage to the drywall appeared to be an issue with drywall tape/mud job. I was considering it to be a cosmetic issue and not needing to be reported on. Boy am I glad I reported it as needing evaluated further by a qualified contractor. 30’ of the PWF at this location needed to be replaced which meant full excavation of the soil at this side of the home. The cheapest bid to fix the wall was $90,000. Needless to say my client backed out and later bought another home.
The point of this story is that even a “small cosmetic issue” may be an indicator of something more serious occurring behind the wall. On a professional level I would never tell my client not to purchase a home with a PWF but on a personal level, there is NO WAY IN HELL that I would buy a home with a PWF. There are just way too many unknowns that are not visible during a visual inspection.
I now disclaim the hell out of any PWF I inspect.

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