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What is the general consensus here on the use of wood foundations? I can pour the footings and frame the basement myself so this looks to be a big money saver. Anything I should know?
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"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
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I would do some serious research on wood foundations. FHB has had some articles including reports of litigation following failures of same. I am of the opinion that wood belongs above grade. If you are still not dissuaded after your research, you need to be aware of your soil and drainage conditions, and this really applies to any foundation.
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Steve,
Get info from APA on PWF (permenant wood foundations) also check out info from AWPA (american wood products asso).
10 years ago we were building low income appartments and looking for a cheap way out. I got info on the system and checked out CABO foundations section.
We had to go to the state building commissioner because the city inspectors had never heard of wood foundations and wanted verification. Turned out our state (RI) commissioner sat on the approval committee for BOCA. He thought the system was great and gave his blessing.
Now you realize that you don't need concrete footings. According to the specs I read and the reasearch report, the wood panels work best on a crushed stone "footing." Cabo calls for 16" wide by 6" deep. We used 3/4" stone but if I did it again I'd use 1/2" - easier to grade. A wide footing plate (we used 2x10) sits on the stone and the 2x6 PT wall sits on that. You only need one 2x6 bottom plate.
We built 4x8 panels off site. Dug the hole, spread the stone, graded stone and set footing plate, And set panels and backfilled all in the same day. When we got good at it we did 2 36'x56' buildings in one day. With a crew of 5 and an excavator.
Be sure to order enough .60 CCA lumber in advance. At that time we could only get .40 CCA and had to special order the more toxic lumber. Stainless nails are required too.
There are lots of water management schemes you can use. At that time we just used the CABO detail with 6 mil poly. Today I'd probably use ice and water barrier or other system.
My father did his own underground workshop 30'x44' using .40 CCA (he was too cheap to special order the .60). After 8 years it hasn't leaked a bit and he only used the 6 mil poly.
I can count on my fingers the number of PWFoundations in my state but I understand there are areas that use them almost exclusively.
Like any building method you have to do it right. Anyone can do a sloppy job with a poured concrete foundation and it will perform well. PWF's won't afford you sloppy luxery.
Go very easy backfilling. If it's a full basement situation you'll want to get the first floor deck on and sheathed before backfilling more than 2'.
I'd still be using the system but folks here won't go for it.
*I have built a number of these and they are all in good working order. I wouldn't reccomend using them in areas where there is alot of water, backpressure or soil movement however. I always have poured footers as our local building code requires them and that is the path of least resistance. The last house I built we used an ICF and it was more costly and no better as far as I was concerned. I am currently working on a system that is based on SIP technology and pre-cast footers that I hope to have figured out in the coming year. A couple of sites of interest are: http://www.exteriorwood.com/htm/toc.htmhttp://www.mcvicker.com/twd/gwdi97/page015.htm
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I agree with the "wood belongs above ground" train of thought. I think the .60 CCA wood is guaranteed for 40 years or something like that. If I'm putting in a foundation I'm hoping for more like 100+ years!
I'd check into the Insulated Concrete Forms (ICF)
They are easy to install so you can do them yourself.
Check out:
http://www.greenblock.com/
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Brian,
CCA .60 is 80 year "warranteed" in adverse conditions. Accelerated (I wonder how they can speed up time) tests show 100+ . Any house should be replaced by then anyway.
*The idea that houses are disposable is both environmentally and economically dangerous. How many people buy a house built in 1920 would subscribe to the idea that it won't last as long as the mortgage. Most warantees are for replacement of the material only and not for incidental damage. It would be small consolation for someone having to replace a whole house, to have the wood for the foundation replaced free
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True, CCA 60 is warranted, but the failure of most wood foundations is structural, not due to failure of the preservative. Attention to soil conditions, drainage, sound structural design and attention to waterproofing detail will be the key to a sucessful wood foundation.
Personally, I feel that wood belongs above grade, I'll stick with a poured in place foundation.
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In my area we have a lot of All Weather Wood(AWF) foundations. Those that were installed in well drained areas using care and approved materials have done well. Those that do not have good drainage or have used such things as galvanized nails vs stainless steel, etc have had problems. Further, AWF, promises the advantage of being easier to repair than masonry.
That said, I wouldn't use one simply because the attitude of the real estate and lending industry toward them is negative. Thus, the ability to sell such a residence is hampered in less than a hot market. Further, some of my friends who have used them say they aren't that much cheaper than other masonry foundations.
*You're right Mike, considering houses to be disposable is perhaps environmentally and economically flawed; not unlike disposable containers, planned obsolescence and throw away childern.Roads, bridges and most commercial buildings all have expected lifespans just as human beings. Some a little longer or shorter than expected but still an expected useful life.A well crafted and cared for 1920's house can certianly be a home but it is unusual to find a regular 1920's house that performs as well, as economically, as comfortably or as safely as one built today. Yes, there is a lot of junk built today, I can't deny that. But again in the paper this morning another early 20th century home killed a few people in their sleep last night. Maybe it was the wiring, maybe the heating system but the fire flew through it too fast and smoke detectors???I think homes are safer now than before and I think they'll be safer in the future. The bar keeps getting raised and most homes built today will not be updated and maintained by the occupants.Don't consider me completely sinister; with every home I build I think someday 100 or 200 years from now someone will cut into it during a remodeling job and think "they just don't build'em this well anymore." The same thought I have when I work on a finely crafted 1920's that has been meticulously maintained and regularly updated.
*Points to ponder.In everything I build or remodel, I shoot a quarter to the concrete, preferably with the current year's date. Hopefully some day some one will find a 200 year old quarter with a hole in it. My own time capsule.The Roman aqueduct in Segovia, Spain still carries water, and its 2000 years old. There is a certain economy of replacement built into the commercial real estate system that allows replacement. Deductable depreciation etc. People see houses as an investment that will at least retain their value. Maintaince and improvement are essential. I often wonder what will happen when large numbers of condos begin to wear out, and replacement decisions rest not in individuals or small groups with a collective interest, but in large numbers of people with diverse and conflicting interests. UVA Architecture Publications THE HANNOVER PRINCIPLES1. Insist on rights of humanity and nature to co-exist in a healthy, supportive, diverse and sustainablecondition. 2. Recognize interdependence. The elements of human design interact with and depend upon thenatural world, with broad and diverse implications at every scale. Expand design considerations torecognizing even distant effects. 3. Respect relationships between spirit and matter. Consider all aspects of human settlementincluding community, dwelling, industry and trade in terms of existing and evolving connectionsbetween spiritual and material consciousness. 4. Accept responsibility for the consequences of design decisions upon human well-being, theviability of natural systems and their right to co-exist. 5. Create safe objects of long-term value. Do not burden future generations with requirements formaintenance or vigilant administration of potential danger due to the careless creation of products,processes or standards. 6. Eliminate the concept of waste. Evaluate and optimize the full life-cycle of products andprocesses, to approach the state of natural systems, in which there is no waste. 7. Rely on natural energy flows. Human designs should, like the living world, derive their creativeforces from perpetual solar income. Incorporate this energy efficiently and safely for responsible use.8. Understand the limitations of design. No human creation lasts forever and design does not solveall problems. Those who create and plan should practice humility in the face of nature. Treat natureas a model and mentor, not as an inconvenience to be evaded or controlled. 9. Seek constant improvement by the sharing of knowledge. Encourage direct and opencommunication between colleagues, patrons, manufacturers and users to link long term sustainableconsiderations with ethical responsibility, and re-establish the integral relationship between naturalprocesses and human activity. The Hannover Principles should be seen as a living document committed to the transformation andgrowth in the understanding of our interdependence with nature, so that they may adapt as ourknowledge of the world evolves.copyright © 1992 William McDonough Architects
*Mike,Your points are well taken and well worth pondering. Thanks for the 'Hannover Principles' I've never heard of them before. I like.
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Unfortunately I can't remember the name of the book or the authors, it was two men I know. One of the guys built his second house and used wood basement walls and foundations. One of the authors built his first house and the book details this in a series of letters between the two authors, one of them being a builder/engineer. The second book was similar to the first but the guy had no more kids at home, etc. and needed a smaller house. Put a wood basement in the second house. I saw both books at the library in the build your own house section. Not a lot of help.
Wood foundations would probably have a bad resale value. Plan to stay there until you die.
As far as houses lasting hundreds of years or even fifty, bullsh--. Structurally they will last but the only people who will buy houses that old are people too poor to afford a modern house with such amazing conveniences as a 2 car garage, 2 bathrooms, ample kitchen cabinets, non-leaky windows. In KC there are plenty of small, 1 car garage 50s houses. They also sell for $50,000 plus less than a modern house with a 2 car garage and 2 bathrooms. How many of the authors touting hundred year old houses here actually want to live in a little house with a 1 car garage? Want as opposed to forced due to economics.
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What is the general consensus here on the use of wood foundations? I can pour the footings and frame the basement myself so this looks to be a big money saver. Anything I should know?