Why a 2x4 is not 2"x4"

[jar546]

 

[e hilton]

Profit.

 

[Msradell]

One thing that has bothered me about lumber is that trees nowadays grow faster and thus the grain is coarser. This produces lumber that is weaker. Thus today's 2x4 is nowhere near as strong as a 1910 2x4. Has this been taken into consideration while changing the specifications?

 

[Jay Smith]

One thing that has bothered me about lumber is that trees nowadays grow faster and thus the grain is coarser. This produces lumber that is weaker. Thus today's 2x4 is nowhere near as strong as a 1910 2x4. Has this been taken into consideration while changing the specifications?

Indeed it has -

https://www.jlconline.com/how-to/framing/southern-pine-2x4-lumber-downgraded_o

 

[e hilton]

One thing that has bothered me about lumber is that trees nowadays grow faster and thus the grain is coarser. This produces lumber that is weaker. Thus today's 2x4 is nowhere near as strong as a 1910 2x4. Has this been taken into consideration while changing the specifications?

Framing lumber used to be yellow pine on the east coast and doug fir on the west. Now spf (whitewood) is used for most studs, and it’s not as strong. SYP is still used for rafters and joists.

 

[rktect 1]

These are just man made numbers. 2x4 actual vs 2x4 nominal is not the issue.

Can whatever you are using hold up the structure? That is what matters.

 

[SCBO1]

Jar, I saw that this weekend on the youtube and I have a little story to tell:

I once worked at a lumberyard out of high school and the owner was the president of the MidAmerican Lumberman's Association. He just got back from Washington and said there was a proposal to reduce the thickness of plywood by 1/64 of an inch and he was asked "if he would think anybody would notice?"

Plywood organization claimed they can produce more sheets of plywood out of a log.

I can tell you he wasn't for it and I believe he voiced his opinion on the matter.

 

[Inspector Gadget]

FYI, I built my house with 2x6 load-bearing members - true 2x6 members (and 2x4s in one case) approved by an engineer and graded for use. Stuff is vastly superior, albeit not as regular in size.

 

[Paul Sweet]

I was taught that wood members were cut to full inch rough sizes, and as they dried they would often warp or twist. Trimming them by 3/8" total (not on one side as the video showed) was typically enough to make the end product straigh. This was increased to 1/2" around 1970, I guess because there was more new-growth lumber that warped more. It did make dimensioning a lot easier in those pre-CAD days.

There was a developer in Richmond in the 1970s who used joists that were surfaced on the edges only, and were a full 2" wide.

 

[Plumb-bob]

I have seen a major change in the lumber we get in Northern BC the last 25 years. Used to be old growth spruce and pine, then as the mountain pine beetle moved through it was almost all blue (beetle) pine. Now as they cut more marginal tree stands farther out and higher up all we get is balsam (sub alpine fir) which stinks, is twisty, and splits easily.
2x12 still often comes in d fir which is always nice.

 

[bill1952]

FYI, I built my house with 2x6 load-bearing members - true 2x6 members (and 2x4s in one case) approved by an engineer and graded for use. Stuff is vastly superior, albeit not as regular in size.

I just built a small barn with rough cut pine. (NY amends IRC to allow ungraded lumber.) Not difficult as long as you understand it isn't all the same. I struggled a little with 2x10 rafters and rembering to measuring from the "top" side. In someways easier. 2x6 studs on 24" centers were perfect for common 22" sash.