# Pressure Treated Lumber Question



## ianmatthew (Jan 20, 2010)

I was given some previously used lumber for a project i am trying to complete. I want to build a raised bed for a vegetable garden. I have read that it is not a good idea to use pressure treated lumber from more than 3 years ago. I am not sure if this wood is pressure treated or not, the wood is stamped with the following. (TP:No.1 KD-19 718 SYP). Can anyone tell me if this is pressure treated?


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## Gerry KIERNAN (Apr 20, 2007)

Welcome to the forum.
I am not up on grade markings, but generally if wood is pressure treated it will have a reddish or greenish colour. Some of the older pressure treated wood had some very harmful chemicals in them. If you are concerned you could line your raised bed with six mil plastic to keep the soil from contacting the lumber. That should eliminate any concern of the chemicals getting into your veggies.

Gerry


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## jaros bros. (Feb 18, 2009)

Some pt is not for ground contact. Almost all the planter beds I have seen are not pt. They are made from hemlock, fir, cedar or some other wood that offers a little durability and natural rot resistance. I don't know if people plan for their raised beds to last more than five years.


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## cabinetman (Jul 5, 2007)

ianmatthew said:


> I was given some previously used lumber for a project i am trying to complete. I want to build a raised bed for a vegetable garden. I have read that it is not a good idea to use pressure treated lumber from more than 3 years ago. I am not sure if this wood is pressure treated or not, the wood is stamped with the following. (TP:No.1 KD-19 718 SYP). Can anyone tell me if this is pressure treated?


Can't tell much from that stamp:

TP = Timber Products Inspection
No.1 = Lumber grading (quality)
KD-19= Kiln Dried to no more than 19% MC
718 = Mill ID #
SYP = Southern Yellow Pine


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## skymaster (Oct 30, 2006)

Usually/normally if a wood is PT than in addition to the stamped info there will also be a retention number stamped IE. .25 which is NOT ground contact; .40 is ground contact. Sounds like your lumber is not pt IMHO:smile:


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## wiseachoo (Jan 4, 2010)

The easiest way to tell is to simply look at the grain of the wood. All the PT wood I ever see has the little "pin holes" scattered throughout the wood faces. Not sure if that holds true for potentially older PT, but anything reasonably new I can identify that way.


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