View Full Version : Below grade wood foundation walls

Paul Kondzich
05-23-2008, 10:14 PM
How many areas of the country have wood foundation walls below grade...anyone. Of about 300 inspections since I have been here I saw a small (1500 sq. ft summer cabin) that was constructed this way. The buyer was knowlegeable about them and said mostly a cost factor. When I left FL. in 05 concrete was about $70 a sq yd. when I got here it was about $160 a sq yd. not including the extra transportation cost for bringing it up the mountain. In the cabin situation the basement was finished so I really could not see the construction technique. After the cabin inspection, I asked a couple of contractor friends, and they said we do that once in awhile...whatever.

Anyway today, 2900 sq.ft house built in 2000 by a well known contractor here as his own house. Now bad news, my camera has been on life support for two days, and I dropped it one last time. All I have is the exterior shot, and the new camera was at my door when I got home, in the rain. You know when the UPS guy makes $29 an hour....never mind that was my past career.

Ok wood frame house on a crawl space. Now we are in the crawl space. Vents at grade level and about 4' of wood foundation wall down to the footer, which is visable. 2x10 bolted to the footer, 2x10 wall from the footer plate to the rim joist all pressure treated including exterior plywood. 2 layers of black plastic wrap on the exterior plywood. Interior walls in crawl space insulated with fiberglass batt insulation. I pulled back the insulation in several locations and checked with moisture meter. Nothing. With the winter snow and the monsoon rain in the summer it just does not seem right to me. But the evidence was there, no moisture that I saw.

As far as the rest of the construction, normally that would have been a poured concrete foundation wall, or less common a block wall below grade. The construction above the wood foundation walls was typical. So is it just me or would any of you not want a wood foundation wall home below grade??

Sorry for lack of pictures, but I have already made a few 90 mile round trips there. Radon inspection etc. Yes I was paid well.

Charles Reiman
04-10-2010, 03:23 PM
I inspected a house here in Central New York today with a wood foundation. The entire basement is finished except about 8' of wall in the utility room where the pressure treated 2"x10" 16"o.c. were observed. The stud walls appear to be sitting on undisturbed subsoil, or hopefully crushed stone and the basement floor has been poured up to the wall. The bays were insulated and when I pulled back the insulation the plywood was soaked as was the fiberglass. Except for a little mildew on drywall in a couple of places there doesn't seem to be evidence of moisture penetration, but those boards were wet. The only visible portions of the exterior plywood were under the deck where the seams on the plywood had roofing cement and on one end where the parge coat had fallen off exposing no waterproof layer on the plywood.
This is a log home sitting on the foundation. The house is 22 years old. The wet walls are very problematic to me. What do you think?

Raymond Wand
04-10-2010, 04:01 PM
Have inspected a number of wood foundations over the years and most had some issues with water leakage. But as many things a lot depends on good construction practices and knowledge of the builder.

They do have a limited lifespan as I recall max of 80 years dependent of course on a number of factors.

Raymond Wand
04-10-2010, 04:16 PM
Further info

CBD-234. Wood Frame Foundations - NRC-CNRC (http://www.nrc-cnrc.gc.ca/eng/ibp/irc/cbd/building-digest-234.html)

Paul Kondzich
04-10-2010, 05:32 PM
Much to my surprise, I logged in and saw my previous post. For those of you that are scratching your head, that was in Colorado. Now it shows me in Florida, where I am now. If this was a wood foundation in Florida, it would be a year or two life expectancy.

Bruce Breedlove
04-10-2010, 06:06 PM
I have inspected a few houses with wood foundations here in Colorado (maybe 3 or 4). They were all in the mountains. I don't recall any significant problems with any of them.

Ken Rowe
04-10-2010, 09:06 PM
I've inspected about 100 houses with wood foundations. All except one had significant problems. Collapse or extensive moisture intrusion are the most common problems I see. The one that had no issues was only a year old.