Rotten Pressure Treated Post

I was just wondering if someone could point me in the right direction or provide some advise. I build a large cottage on post 11-12 years ago, 30x40. I just discovered that all my post are rotten, some more than other (evident by the sinking). I call the contractor and building material supplier, they said the posts were not rated for below ground, but at the time nobody knew that pressure treated lumber had different ratings, above and below ground. I see a guide on the site does clearly indicate what type of posts should have been used for a below ground application like mine. However I am not sure if this was known in Fall2005, when my post where installed.

So, I am curious if pressure treated wood had ratings in Fall 2005? Or was there some other type of information out there that contractor and supplier would have has access to, for the selection of the proper post, or was all pressure treated lumber the same in 2005? Any thoughts on liability, the contractor, the supplier, or me the home owner?

thanks, Terry

I believe that there has always been a value placed on wood below grade ie) PWF foundations

Try this:

From: (The PDF link is above the author’s face. Scroll down.)

All wood rots I don’t care how it’s treated

I installed 246 fence posts in 1990. They were CCA treated for ground contact. NONE have rotted or broken as of last week. My neighbor put a 6x6 pressure treated post in the ground 3 years ago. Completely rotted and full of termites and he had to replace it last week. I am putting in 75 more posts over the next couple weeks and since I have a farm, I can special order the CCA treated and not have to worry about rot / insects. The new crap they started using in 2003 when CCA was only allowed for commercial use, is worthless.

All foundation grade pressure treated sold in Ontario was sold with the grading stamp as foundation grade. That was the only wood rated to be used below grade as far back as 1980 when I built our first pressure treated wood foundation. It is still there with no problems developed to date. The current grade stamp goes back to 1989 but there was an earlier version as well I just do not have it.

CSA - O80.15-M89 Publish date: 1989-03-01. All plywood and lumber used in PWF’s must be pressure treated with preservatives in accordance with CSA - O80.15-M89.

The architect that designed your cottage should have specified the type/grade lumber to be used. He should be the first yahoo at the top of the ‘lawsuit’ list! You did use a Certified Architects building plans, right?

That is because the pressure treated wood from 1990 had a chemical with arsenic (CCA). The copper additive they use now doesn’t compare to the old stuff. The decks that were built 20 years ago are still standing strong rather than some of the 10 year old decks now that need repairs.

CCA does not stop wood rotting. It deters ants and termites and will kill any mold spores within the wood, but does not stop the wood from being re-infected after treatment.

Wood decays because of fungus. Fungus needs 4 things to proliferate quickly: water, oxygen, food (wood) and favorable temperature (40F – 105F).

You can take two posts of equal quality, size, type, density and treatment. Put one in well drained soil and one if poorly drained soil, and the latter will rot quicker.

Before you consider “suing” anyone, consider this, can you prove that over the lifetime of the wood in the soil you have maintained optimum conditions to ensure the wood decays at it’s slowest rate?