On 2007-07-13, BobK207 wrote:

On Jul 12, 8:37 pm, "Art" wrote:

Here is the new information. The portion of the floor with the tub
is cantilevered out 2 feet. That means that some of the tub will
be sitting on the sill plate.

Is the tub centered or nearly centered over the wall below? If so,
almost all the weight will be carried by the wall, and you need only
concern yourself with whether that wall is strong enough. Your 2x10
joists will be strong/stiff enough to carry the tub load to the wall.
[Imagine cutting through the joists at the edge of the tub over the 6'
span; the joists just have to be able to carry the weight back to the
wall as a cantilever on either side of the wall.] Sounds reasonable,
Bob?

since deflection goes as span^3 the 2 ft cantilever section is
actually stiffer than the 6 ft span section.

Hmm, that's not really true, is it? A unit point load at the end of
the 2' cantilever will induce a moment at the support of 2 ft-lbs. A
unit point load at the middle of the 6' span will induce a moment
there of 1.5 ft-lbs.

Cheers, Wayne