Tag Archives: MCA .23 treatment

Treated Lumber for In Ground Use

Treated Lumber – Justine Schools a Major Lumberyard Chain

When it comes to pressure preservative treated lumber, ignorance from the supply side seems to be bliss and there are way too many folks out there happily selling under treated product.

For your entertainment pleasure I bring you a discourse between Hansen Pole Buildings Lumber Wizard Justine and the manager of one of a 145 plus location lumberyard chain which supplies materials to both post frame builders and DIYers.

Justine: “Good Morning. Can you confirm 4×6’s and 6×6’s treated to .23 retention level?”

Manager: “No. They are ground contact treated to .14pcf.  And our 2×4 and 2×6 are above ground .05pcf. We do not carry .23pcf in any of or lumber treatments.”

Justine: “I need these to be in ground contact treated.  So if you’re using MCA I need them to be .23 which I have gotten with Xxxxxx many times.  Would you please quote those.”

Manager: “UC4A .15 is ground contact for structural posts and deck posts. 

I can special order in UC4B .23 (or .31) Critical – for permanent wood foundations in full units for you. You would have to purchase 24qty of the 4x6x14’s and 24 of the 6x6x14’s and it will take me a couple weeks to get in.

Let me know if you want to do that?”

Justine: “Good Morning (another manager in same chain),

.15 cannot be buried in the ground, it doesn’t meet code.

.23 I have ordered in pieces and less then bunk units with Xxxxxx many times.

2nd Manager, can you help 1st Manager with this one.”

Second Manager: As my location is a part of the Xxxxxx Lumber division I am able to pull the post out of our location in Millersburg.  My suggestion to 1st Manager would be to check and see if he can have them top loaded by the piece on his next treated truck.  Other than that I am not sure how to help.”

First Manager: “I just talked to Escue the treatment plant and they do not sell less than a unit. They will not top load a few boards.

 According to Federal Gov’t Regulations (AWPA Standards) the .14pcf UC4A Can be buried in the ground. It is absolutely in ground contact.”

Justine: “You are false, It can touch the ground but cannot be buried in the ground.  Code is UC4B is in ground use.

Have you tried Universal Forest as I know Xxxxxx branches use them as well.”

First Manager: “Unfortunately someone is feeding you false information  – Here is an ICC (International Code Council) report – all of the treatment plants are on there – ( Universal Forrest Included).

Look at Page 5 – .15pcf — Ground Contact – In ground

              Page 5 – UC4A – Ground Contact – In ground

I would like to take care of you on this job for 2nd Manager, but I can only sell you what I have Sir…”

Humorous sidebar – First Manager has not yet realized Justine is a member of the female side of the human species.

Here is where I step in to do some educating:  This is not meant to put you down, however you have been given some bad information.


Please read this article, then look up the cited section of the International Building Code which confirms Justine is correct:
https://www.hansenpolebuildings.com/2012/10/pressure-treated-posts-2/.

Thank you for your understanding.”

 Considering ordering post frame building materials or a pole building kit package from a lumberyard? This is a chain of locations which absolutely should know better, yet does not. Do you want to risk your beautiful new pole barn having posts which rot away?

I think not.