Re-using old pressure treated lumber

[Pete Kurki]

I got about half-dozen 12 foot long 2 x 12 planks when I tore down old horse stalls in my barn. I have been contemplating of reusing them for making a garden arbor for my wife for our wedding anniversary. The planks are at least 10 maybe 20 years old, and a few questions came to mind when I was test cutting one of the planks:

1. The planks are still green on the surface, but a cross cut reveals a natural (not green) wood color in the center of the plank, about 50% of the cutting surface. What should I think about that? The center never got the preservative, or perhaps lost it over the years?

2. My first preference would be to paint the arbor white. I know that typically PT lumber cannot be painted at all, but how about this kind of over 10-year old stuff? Probably all the chemicals that are going to come out of it have done so a long time ago. My second but less favored option would be to just stain it so that it has at least an even green color.

3. This old PT lumber obviously contains the old style arsenic based chemicals. Are there any extra precautions I need to take when I am cutting and milling the stuff. I will naturally be wearing a dust mask and I also have a powerful DC and double air cleaners in the shop. Or should I actually consider this stuff so dangerous that it should not be milled at all?

Appreciate your expert advice, as always.

Our anniversary is actually today, but my wife happily accepted a picture of the arbor as a promise for a delayed gift. Anyway, it's about time to get started...

Pete

[Paul Girouard]

1. The planks are still green on the surface, but a cross cut reveals a natural (not green) wood color in the center of the plank, about 50% of the cutting surface. What should I think about that?

Normal the treatment never / hardly ever goes all the way thru.




2. My first preference would be to paint the arbor white.


I know that typically PT lumber cannot be painted at all, but how about this kind of over 10-year old stuff?

Who told you that? It's fine to paint it , this 20 year old stuff you should pressure wash then let it air dry before painting. But it should be fine .



Probably all the chemicals that are going to come out of it have done so a long time ago. My second but less favored option would be to just stain it so that it has at least an even green color.


Also do able , again P. wash it, let it dry then stain.

3. This old PT lumber obviously contains the old style arsenic based chemicals. Are there any extra precautions I need to take when I am cutting and milling the stuff. I will naturally be wearing a dust mask and I also have a powerful DC and double air cleaners in the shop. Or should I actually consider this stuff so dangerous that it should not be milled at all?

Depends on how anal you are about rules, I never worry about it. Hell I'm to mean to get sick anyway so you may want to use some type of protection. :D

Appreciate your expert advice, as always.


Your welcome so of the others may also be experts , we'll see.

Our anniversary is actually today, but my wife happily accepted a picture of the arbor as a promise for a delayed gift. Anyway, it's about time to
get started...

Good idea , she's be watching , and IF you want another anniversary .........................:eek: you best get going eh!



Sounds like a great Re-use of the materials. Good luck!

[Joe Jensen]

As said above, it's normal not to have the PT go all the way through. I haven't used any, but I understand one can buy a material to self treat cut ends of boards. I assume it's not as effective the original PT as it's not PT...joe

[Tom Veatch]

Second Paul's comments on the precautions to take. Remember the arsenic based PT lumber was in use for a lot of years and at least a few of us survived the exposure.

[Rich Engelhardt]

Hello,

PT and paint is/can be a problem, even with older material which has "dried out sufficiently".
Granted after 20 years, you're chances of not having problems are vastly improved.
Solid or semi transparent stain usually works a lot better.
W/the wide spectrum of solid color stains available these days, there's not much reason to use paint.

HD sells Beher solid stain in a brilliant white.
It's good stuff.
I'll be using it this afternoon on my mother in law's treated deck rails.

I/we just got finished removing the paint from 2 PT decks which are ~ 15+ years old.
The previous owner had painted them to "spruce them up" to sell the house by painting them gray.
PW, then scrape then PW and more scraping followed by a belt sander.
It's a miserable job that I wouldn't wish on anyone.
The PW can tear up the soft pine pretty good if you aren't careful. It's tough to be carefull 100% of the time, so ours got tore up pretty good in some places.

[Rich Konopka]

Hello,

PT and paint is/can be a problem, even with older material which has "dried out sufficiently".
Granted after 20 years, you're chances of not having problems are vastly improved.
Solid or semi transparent stain usually works a lot better.
W/the wide spectrum of solid color stains available these days, there's not much reason to use paint.



I agree with Rich on this one. The LOML primed with an Oil based primer and White Cabot Stain for our pressure treated Arbor. It came out real nice.

[Pete Kurki]

Hello,

HD sells Beher solid stain in a brilliant white.
It's good stuff.




Thanks for the lead. Guess my noviceness is showing as I did not realize that I can get stains also in white.

Pete