For a heavy duty industrial type concentrated floor loads I suggest forgetting the 6 x 6 joist and look more toward 3 x 12 or 3 x 14 floor joists similar board feet but far more capable bearing capacity, assuming a central longitudinal beam. The dovetail connection to me is a weakening joint regarding the central beam.
Hey Roger, thanks for the note. I'm feeling a little foolish now and wishing I'd thought about the loading when cutting the timbers, but to be honest, I've only recently gotten into the world of large industrial machines so wasn't thinking of weight too much at the time. So I'm sort of stuck with 8x8 sills that the joists will be attached to. Would you suggest scalloping out the bottom of the 3x12s so they could rest in pockets cut into the 8x8? Would reduce the overall capacity of the 3x12s I suppose.
Thanks again!
B
