Ground Contact PT Lumber OK for Making Trellis

[Bob D.]

Wife want a trellis for growing tomatoes and such.

Is it safe to use ground contact PT lumber for a trellis?
I have some left over from a outdoor project that could
be put to use. With the price of lumber so high I might
use this if acceptable.

Searched but didn't find anything on this.

 

[Tom the Remodeler]

Hi Bob!

I don't know for sure, but I'd suggest the nature of the pressure treating agent might factor into the decision. The old pressure treated lumber often included some amount of Arsenic. I have no clue how that would factor into whether it's safe to be in contact with something you might eat or not. The newer (last ~20 years or so) treated lumber should not have arsenic.

If it's just a decorative outdoor piece I'd say "let'r rip!", but because it would potentially be in contact with food you may need to take more care.

Treated lumber should have a tag at the end of the board telling you who the manufacturer is and what kind of treatment process was used, perhaps you can inquire with the manufacturer? 

 

[Vtshopdog]

I rebuilt my deck fall 2020 during peak Covid and PT lumber was very difficult to find.  Locally a “B” level yard had stock but I was skeptical of their quality. Ended up doing a bit of a deep dive to learn about PT ratings before buying from them.  (stock they had was just fine)

Here is link to a trade association standards page.  Tag on end of your boards will have a code that you can look up in the linked table.  Once you ID type of chemical used to treat your stock you can likely search specifically for contact with food plants.
https://awpa.com/info/technical/homeowners

FWW - They have a food disclaimer below the table.

 

[Bob D.]

Thanks everyone. Decided (forced by SHMBO) to go with cedar to
match the potting bench and vertical garden I built her last year.

Spit one out this afternoon and it looks good. Probably have to
make a couple more once she shows her sister and it will snowball
from there no doubt.

 

[Packard]

Right now I am finding that resin moldings are cheaper than wood (it used to be the other way around).  Perhaps look into resin alternatives.

 

[pixelated]

I don't use PT for any food gardening structure.

FWIW, my neighbor, who is a retired commercial builder opines that PT lumber will the the lead paint of modern times.

 

[Bob D.]

Right now I am finding that resin moldings are cheaper than wood (it used to be the other way around).  Perhaps look into resin alternatives.

That's an option I hadn't considered. I might look into it but I have the one built so I'm off the hook with the Wife. Only need to build more if someone comes asking or I get volunteered by the Wife to make one for someone.

Only downside to using that stuff is the cut edges are not finished very nicely. If I could get nominal 1" x 2" material that might work.

 

[Packard]

I just checked, a 4' x 8' sheet of vinyl lattice is $25.00.  The cap mouldings are $9.00 for 8 feet.  No painting.  No splinters. 

I've cut these with regular woodworking saws. 

They look too white to be wood, but right now that would be my choice.

I used this stuff to hide a window A.C. unit that protruded only my deck.  I left 6" to the right and left and to the rear.  The bottom was open and the top was the eave of the house.  I got it all done in an afternoon. It looked good.  The AC would not get cold.  I thought this was plenty of ventilation, but I was wrong. I had to take it all down.

 

[Bob D.]

Thanks but the lattice look is not what she wants.