I'm using pressure treated, ground contact lumber like this one bought from Home Depot for an outdoor project in my backyard. Parts of the lumber are buried underground, and some of the buried ends are cut by me before burial. I don't apply any sealants on top of the pressure treatment. I called Home Depot to confirm that burying even after cut is OK, and they said it is, and that it's expected to last 25 years. When I look online (at blogs etc.) to confirm though, I see that some people recommend at least 0.40 lb./cu.ft.chemical retention. The Home Depot lumber I use has only 0.15 lb./cu.ft. Is the discrepancy because Home Depot uses some superior chemicals that requires less lb./cu.ft.? Can anyone confirm from experience that such department store lumber lasts as long as they claim?

  • Rewind for a minute and think about the criteria that you used to select Home Depot as your supplier. You see them on TV. You see flyers in the paper if you get papers. They are a national chain. They have a wel-lit mall location with a huge, clean parking lot. Their store is professionally styled for consumer appeal. It's a big-box experience and it's open late. They have a New York marketing team who's spun them as "same quality better price". What do these factors indicate about their lumber quality? Mar 18 '18 at 18:49
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    No, none of those factors to me are necessarily indicative of product quality one way or another. Mar 18 '18 at 19:18
  • After a lot more research I found that the websites that recommended 0.40 lb./cu.ft. are talking about the alkaline copper quaternary (ACQ) preservative. The wood that I bought seems to use micronized copper azole C (MCA-C), only 0.15 lb./cu.ft. of which is recommended by AWPA for ground contact. I know that this is a newer chemical so projects that have used this type of wood may not be many years old, but if anyone can share their experience, I'd still like to know how their wood is doing. Mar 19 '18 at 1:38

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