I know that the red numbers found every 16" on a tape measure are for laying out studs in a wall. But what is the little diamond shape at 193⁄16 "?

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Many tape measures mark 16" stud measurements in red along with a slender arrow, and 19.2" floor joist measurements with a diamond. The two marks meet up at evenly divisible 96".

Q:

I know that the red numbers found every 16" on a tape measure are for laying out studs in a wall. But what is the little diamond shape at 19316"?
—Robert Roth, Westland, Mich.

A:

Robert, the little diamonds are a nod to newer construction materials and standards. Engineered lumber joists—manufactured substitutes for conventional dimensional lumber—can carry a heavier load than the ordinary pine lumber it replaces. So rather than six joists for a standard 96" sheet of plywood, it takes only five engineered joists to bear the same load. 96" divided by 5 comes to 19.2" (slightly more than 19316  ").