Latest Discussions : Tools & Workshop


04:43AM | 06/25/03
Member Since: 06/24/03
1 lifetime posts
I am rebuilding my deck and have had some contractors state that they would use #2 pressure treated decking lumber instead of #1. What is the difference between these two grades of lumber?


04:14PM | 06/25/03
Member Since: 12/27/02
543 lifetime posts
#2 or better is the grade supplied by lumber companies. It meets code and there is no noticable difference for deck applications. Generally #1 "only" is used when specified by a structural engineer. Which is rare, you can get maybe an extra foot or so on a span typically, so if you're out to the limit or building a beam something like that #1 may be asked for.

Alter Eagle Construction & Design

[This message has been edited by Altereagle (edited June 25, 2003).]


06:22PM | 06/29/03
Member Since: 11/19/02
59 lifetime posts
Respectfully, I must disagree AlterEagle- (unless you're only speaking to using a #1 vs a #2 on the supporting structure of a deck)

We treat both #1 and #2 Southern Yellow Pine at my plant. Since SYP makes up most of the pressure-treated lumber that's produced in the US, it's a good bet that BrianZ will be using SYP. That said, there is a distinct visual difference between the two, as well as a slight structural difference. There are less wane and knots allowed per SPIB grading rules in a #1 than there is in a #2. That alone is a big difference visually. #1 material is generally slightly stronger than #2, but I don't see any reason to go wild and use #1 material on the joists and ledger board on the deck. Additionally, your posts are generally going to be #2 if they are 6x6's, as #1 is very difficult to come by in SYP timbers.

Decking will be either PREM or STD, Premium being the equivalent of a #1, and STD a #2. I'm not a big fan of using 2x6 as decking. I'd rather go with a 5/4x6 radiused edge decking. And if it was my deck, I'd use premium decking. It's just a lot better than the standard.

I hope this helps Brian...

[This message has been edited by JayF (edited June 29, 2003).]


04:54PM | 06/30/03
Member Since: 12/27/02
543 lifetime posts
Good point Jay, I was only refering to structural.

Here on the west coast we wouldn't even think of using a treated lumber as a finish, we use composites, redwood, cedar & some exotics like ipe (pronounced eepay)among many... but never a treated lumber.

Thanks for clearing that up, I recall using treated pine back east but haven't for so many years never thought of that as an application even!


02:42PM | 09/09/14
I purchased treated 2/4's from home depot about a month and a half ago and stored them in my garage. They have warped and twisted so bad that I won't be able to use them. Is this normal? The wood is for a fence project and I installed 4x4's that also warped and twisted.I will have to replace some of them and that's a lot of wwork, busting concrete and such.


06:14PM | 07/21/15
What is the rule? How much wave, defect or knot can be in a #1?
Is it just less than a #2 that was made that day? I am looking at KDAT but most lumber yards say it's not worth stocking. Is that because they don't have any?


11:40AM | 09/07/19
To the comment about leaving PT wood in a garage..

Treated lumber comes wet from the manufacturer. It's Southern Yellow Pine. As it drys out it does tend to warp as it dries. That's the nature of it. So you never want to leave it somewhere where it can dry out or it will warp. Once it is installed and fastened, it's not going to warp. So if you by treated SYP, you are going to want to use it right away..

I know this was old, but this is good to know.


08:48PM | 07/25/20
It's junk wood. Treated SYP is genetically engineered to grow fast and yield volume, not quality like quarter sawn wood of the old days. Notice that each piece is heart wood. Warps and shrinks like crazy. I got better results with a local lumber yard. They claimed it was kiln dried but I'd say 1/2 the way dry. Home Depot treated SYP 2x6s are just junk wood.


07:40AM | 09/11/20
I’m putting together a prefabricated shed on my property, but too small to consider pouring concrete for a slab.
Instead I’m using the pressure treated wood to be placed on dirt as it’s foundation..
Should I consider this, and if so, should I keep it sealed to preserve its life to prevent it from BB potentially rotting over time?
Thank you


08:04AM | 09/19/20
BV023310, put cement blocking under it to pick it up off the dirt, that will make it last significantly longer


08:54PM | 10/04/21
You can also put the pressure treated lumber on polyethylene sheeting with some gravel between structural members to hold the sheeting down. This would not work if water can leak from above. In that case it would be best to lay down some gravel and set framing on the gravel.

Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.

Reply choose button


Post new button or Login button