How much weight can a 2x12x12' untreated pine board safely support?

... I have two boards sandwiched (no OSB between - no glue) and the two sandwiched boards are only supported by square columns at each end. The columns support at least 8000 pounds each.

  • 1
    Is it on edge or flat?
    – mmathis
    Jul 12, 2017 at 14:39

2 Answers 2


Putting those numbers into the sagulator, a 12' 2x12" Ponderosa pine board lying flat could support 100-125 lbs with about 0.2" of sag in the middle.

If it were on edge, it could support several thousand pounds. The sagulator says borderline sag began at about 12,500 pounds, but that was beyond their stated target sag of 0.02" / ft. I found that target sag at about 7000 lbs.

  • Not flat, on edge as in floor joist, or rather, I'm using as a header for floor boards measuring 2x10x10' to sit atop, (no hangers used on the 'header' end), 16" on center. (Floor joists span from wall 8 feet to top the sandwiched header.
    – Ellen
    Jul 12, 2017 at 15:11

One 2x12 can support about 180 lbs. per foot or about 2,100 lbs. total for a 12' span. However, the code allows increases for short duration loading, (i.e.: snow loading less than 7 days, etc.)

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