Pressure Treated Lumber

[Shannon Wyatt]

I could use some help/advise folks.

I build a lot of outdoor projects. I try to purchase the best priced pressure treated lumber. But, I often find that the color of the pressure treated lumber differs from store to store. Therefore I cannot use left over lumber from the last project because the other store had the best price this time. I may go to one and find the lumber is an olive green tint and then go to the other and find that it is almost clear with just a hint of green. Why is there such a difference in color? Is their anyway to over come the color difference? I have tried wood bleach with limited success. Usually if the lumber is dry I can get the wood to almost match by bleaching it. Any other advise or help?

[Julian Wong]

Shannon,
If you don't already know, there are different grades of pressure treating. The olive green ones you see are those rated for ground contact or to be partially buried as posts. The light green ones are rated for above ground contact (less preservatives/chemicals) only.

[Jason Roehl]

Different manufacturers also use different treatment chemicals.

[Shannon Wyatt]

Yea, I knew they were different grades of pressure treated lumber, but I did not know that you could tell the difference just by the color. Why is that? Do they use more/different chemicals in the below grade lumber and less in the lumber for above grade?

[Jeff Monson]

After a short time outdoors and exposed to the weather, the difference is very minimal.