Wood Foundations

Recently I was retained to inspect a Pressure Treated Wood Foundation house.

While there with the client and agent, the agent asked the client if he was sure he could get isurance, and to check to see if his insurer would insure the house. The answer came back, no they would not insure the house as it is pressure treated wood. It also turns out from further dicussions that future buyers of wood foundation houses will not be issued insurance either. No insurance no mortgage.

There goes the value of anyone with a home that is wood foundation. They may want to consider having new foundation installed.

Has anyone else run into this?

There are several homes in my area that I have inspected over the years, not many people know much about them or how long they will last.

I apologize if you are only looking for Canadian reponses to this, but I would recommend getting a second opinion on insurance. There are literally hundreds of thousands of these foundations out there and I haven’t heard of any issues that would prevent insurance. You can have issues with any foundation and properly installed wood foundations have many advantages over concrete.

Charles thanks for the input. But the insurers are the ones setting the rules. From what I was told my clients said trying to get insurance will be a task in itself. Needless to say my client walked and the home owners are not to pleased. This is another case of Insurance industry acting as code authority, considering these homes were approved by government agencies. Like so many things insurers are calling out up here, such K&T, Alu, cast iron waste, woodstoves, oil tanks… Talk about the ultimate Risk Reduction on writing policies. Where would we be without insurance? (tongue in cheek) :wink:

Insurers may set their own rules, but it defies the loigic and accepted standards accepted by both national and provincial building codes. Even CMHC provides details and reference to CSA standard O80.15 in the text Canadian Wood-frame House Construction.


Yeah I know…, but speak to the insurers. :slight_smile:

Ontario Hydro has never condemned k&t, or 60 amp service, Alu. wiring, but the insurers see things differently. I am surprised there is not a hue and cry from the public.

Damn those insurers. :frowning:


I once built a pressure treated wood basement for an existing cottage. I was working for someone at the time as a carpenter. I asked the owner I worked for why it wasn’t a masonry foundation. His response…“if it is a masonry foundation, we as carpenters would be out of work!”

1st thing that happened was the walls started bowing as they were backfilling…what a friggen mess that was!!!

I have seen maybe a dozen in my inspection career (since 1991). Half of those had problems with water entry. The one most recently in which the client could not get insurance was okay, couldn’t see any foundation problems, but it was a finnished basement. Outside had about a foot of snow around the structure, but everything appeared to be plumb and square.

I saw a lot of them out west, mainly Saskatchewan. The big problem was as someone said, when you go to backfill. They do not take a lot of pressure and the backfill height is very low.
Many people feel the off gasses were a detriment to health, but no one has any solid eveidence.
What about an insurer that has an office out west that is familiar with a wood foundaton.
PS, I did not like them myself… they were hard to anchor brick to.

Does anyone have a good picture of these? I’ve never seen one.





Here is one from upstate NY




I live in a house with a wood foundation. I haven’t had any water penetration through the wall and no rot that I have seen. My house was built in 1984. The one problem I have encountered was the bottom of the walls pushed in because the builder skimped on the floor material. It has 2x4 framing 24 " on center with only 1/2 in sheeing. Needless to say the enire house shifted and there is hardly a level floor in the place. If the builder had poured a concrete floor prior to backfilling I think all would have been fine. I personally like the wood foundation and I see a lot of them in My area of saskatchewan as the previous post has indicated.
Aulden Reid

That does not appear to be a true PTWF. I can see a concrete foundation under the wood flooring. A true PTWF sits on a layer of crushed stone about 18" thick. I have built more than a few of them. Properly constructed they are as good, if not better than any concrete foundation out there. It is all in the details. The ones I have built are still in as new condition and do not have any water intrusion problems. The idea that one should have a concrete floor poured to avoid back fill problems is just silly. If the floor is properly constructed in the first place the issue of bowing does not occur. As with any foundation you must install the first floor decking before backfilling. The problem with backkfilling leading to bowed walls is usually the result of the use of improper fill to begin with and the use of heavy equipment to perform the work. I have seen a concrete wall bowed from not doing the backfill properly. The contractor used a small bulldozer to backfill and then drove too close to the wall to compact it. I know, sounds stupid, but you cannot legislate stupidity.
Ray’s client should have gone to the insurance company that held the policy on the home to begin with. If they insured it once most ikely they will do it again. In the worst case a structural engineer could have been called in to verify the stability of the foundation and with his stamp on it the insurance company would not have much choice.

Not all PWF homes have concrete floors. They can be constructed with crawlspaces, and the crawlspace floor is crushed stone.

The insurers call the shots. They just don’t want to insure them. There is just no pleasing the insurers. Look at the ridiculous rates they are charging for E&O,

Personally I was pleased my client didn’t get the house, even though he was set to go through with it. A dissapointment is a blessing.

For all of you who would like to know more about PWF’s come on out to the “Great Lakes-East Chapter” Event in April. (Davison, Michigan - Just east of Flint off I-69)

Friday, April 13, 2007 Learn about: (Chapter Meeting)
**Nu-Wool WALLSEAL cellulose insulation.
**WaterFurnace geothermal heating and cooling systems.

Saturday, April 14, 2007 Permanent Wood Foundation’s (PWF’s) for Home Inspectors (Open to All) (8 hour course)
PWF’s are becoming more popular every day. All wood basements can be dryer, warmer and last longer then traditional block or poured foundations if they are designed and constructed correctly.

This will prove to be a very interesting weekend with a lot to learn for all!

More info can be found at the Chapter WebSite.

People keep saying they can be better than concrete. Why?

1] More energy efficient. (heat loss/ heat gain)
2] Dryer (When designed & installed properly)They are designed to divert water away from the foundation! Not to keep the water out!
3] Studies are showing that they retain their value better then block & poured foundations.
4] Cost less to finish the basement as living space.
5] Construction time can be cut by up to a week or more!
6] They can be installed where traditional basements can not!They have been installed below the water table in many areas and are still dry!
On the Down Side
1] You must hire a proper engineer to design the foundation.
2] The installer must be watched during the entire installation process.Most do not understand that they are designed to divert the water rather then to push back the water like traditional basements.
3] When installing plumbing & electrical you can not run horizontal runs… they all must run vertical to the floor or ceiling!!!


I have seen many inspected three One was great two where disasters .
If I had two homes the same one wood and one Block or Concrete.
And the wood was $100,000:00 and the others where $50,000:00 more I would not take the wood .
Future sales and future concerns would make me stay away

Roy Cooke


That is why I am having this training course here. The instructor is one of the people who have written the 125 pages of code that will be added to the next update of the code books. The current code refers to a document that tells you nothing about how to design or construct a PWF. It only tells you that a PWF is made from wood.

They are growing in popularity… Their are more in Canada then here in the states. Alaska, I have been told, have a lot of them also. Due to the short construction season when it comes to concrete curring time.