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Whatcom County Home Inspector (King of the House) Pressure Treated Lumber, What Is It Good For?

By
Home Inspector with King of the House Home Inspection, Inc. Home Inspector Lic #207

 

  Pressure treated lumber is advertised as having a long life (some say 40 plus years) with direct earth contact. The manufacturers soak the lumber in chemicals, it penetrates into the wood at the outside surface. The most vulnerable area is where the wood is cut, such as to length and then that end dropped in a hole for use as a fence post. In theory, if cut and buried, more treatment should be applied at the cut. My personal experience is that, usually, this lumber does last a very long time. I have some fence posts, I put in 20 years ago, that I have since dug up to move them. All of these were still as good as the day I put them in the ground. On the other hand, a very few times I have found pressure treated wood under decks, even posts resting on piers, where the wood had decay apparent. As with all of life this goes to show that there is the design, the plan, the odds and sometimes there is an exception and something does not turn out as was expected. It is out of the "norm".

That said, pressure treated lumber, and how to describe the circumstances when found, is not clearly defined by the Washington state wood destroying organism laws. The wood is manufactured for ground contact, so having it touch the earth is not necessarily a defect. At one point I asked the WSDA about this issue and was told this -- Fact: Pressure treated wood in contact with the soil will last much longer if all soil contact is eliminated. An inspector should probe, if possible, all pressure treated lumber which has soil contact and, if it is decayed, then call it out that way. If no decay is apparent, an inspector might, to be helpful to the client, say that grading soil back from the lumber, or putting it up on a concrete pier, will make it last longer. This advice may, or may not, make sense depending on the design elements of the structure, say a deck.

Personally, as an inspector, here is what I do. If I see pressure treated lumber in a crucial role, and it is in contact with soil, then I call out for removal of the soil; for example, when I find pressure treated lumber used as a post under the house and it is buried by dirt. In that crucial role, you do not want to take chances of rot. The photo below is another example where I called for removal of soil. This is a deck that is probably about 8' off the ground. It has four columns supporting it at the front. One of these is on a pier above the soil. The other three were on piers, correctly so, but there was about 4" of soil spread over them. In this case, just get the soil off the wood. That is an easy and correct call. We do not want the posts deteriorating on a high deck. High decks coming down are dangerous! (The green at the bottom of the column is caused by continual moisture seeping into the wood)

Now, on the other hand, if I am inspecting a house and find a couple 4x4's for support of a handrail sunk into the earth, at each side of the steps from a modest porch or deck, I check the lumber at the ground level and, if it is fine, then I do not say very much. No grading is applicable, with the post sunk and it seems to be holding up well. In my view, these simple outdoor uses, such as this or as fence posts, are common and, down the road, the repair is easy to do and the area also easy to access. The repair can be done by a workman who is affordable and no structural damage is likely to take place.

Thanks for looking.

Steven L. Smith

www.kingofthehouse.com

 

Posted by

Steven L. Smith

If you enjoy nostalgia and music of yesteryear, click on Elvis' gold record to visit This Day In History. To explore The Stories Behind The Music blog posts click on the electric guitar. 

 

        

 

 

 

 

Comments (2)

Marlene Bridges
Village Real Estate Services, Inc. - Laguna Hills, CA
Laguna Homes|Laguna Condos|Laguna Real Estate
Steven - I love your common sense approach to doing inspections.  Not all inspectors are as pragmatic as you are.  They can absolutely scare buyers (especially firt time buyers or people who are not very handy) to death.  I'll bet there are many agents who wouldn't think of hiring anyone else to do their inspections for buyers in Washington.
Nov 11, 2007 10:03 AM
Steven L. Smith
King of the House Home Inspection, Inc. - Bellingham, WA
Bellingham WA Home Inspector

Marlene,

I have quite a number of local realtors who feel as you say. Then there are some others who do not like me because they think I "see too much." I had one tell me that once -- "you see too much and I do not like inspectors who do that. I am going to get an inspector who makes sure my deals always close". That was disappointing to hear. I try to be practical, honest, but do call out defects that I believe will be problems for my clients. I think my blogs, and the approach I use, are indicative of my reports.

 

Steve

Nov 11, 2007 10:50 AM