thehip wrote:

I have a home built around 1930-35. it has 2x10 floor joists spaced 16"
on center. They are 12 feet from foundation wall to center support beam
running length of the house. The center beam sits atop 3 lally columns.
My question is how much weight can this type of construction support?

S = bd^2/6 = 1.5x9.25^2/6 = 21.4 in^3, M = fS = 21400 in-lb, and W = 8M/L
= 8x21400/(12x12) = 1188 lb per joist, ie 1188/(12x16/12) = 74 psf for
the joists, which would include the weight of the floor itself.

Nick