"BobK207" wrote in message
...

Dave-

That is a pretty cool design concept to replace a wall with a beam.

But the joists will move downward until the beam deflects enough to
take the load that the wall was supporting.....depending on the beam
sizing & the ceiling load (actually in this case, the 2nd story floor
& ?). The deflection at mid span could be in the 3/8 to 1/2" range.

Plus in the OP's I'm pretty sure that your concept would place the
beam on the floor of the 2nd story.

But still a neat concept.


Truth to tell, I missed the fact that the OP was dealing with another
story vs. an open attic or I probably never would have posted this as a
solution.
As far as your concerns about deflection, we measured absolutely zero in
this particular application. I do recognize the necessity of sizing the
beam to carry the load. But, in this case the load is 2X6 ceiling joists
and half-inch painted drywall and the beam consists of 3/4 inch CDX plywood
sandwiched between SYP 2X12s though I recall there being either two 10 foot
2X12s on either side of three pieces of plywood or an eight and a ten on one
side and a ten and an eight on the other. I don't recall the length of the
span except that it was around 18 or 20 feet. We must have put a couple of
hundred 3 1/4 inch nails in it in addition to the thru-bolts in each angle
iron brackets. We probably even considered a 1/4 inch steel flitch plate in
lieu of the 3/4 plywood. Assembling the beam in the attic space was hard
enough w/o having to contend with a couple of pieces of 1/4 inch by 11 X
eight or ten foot steel plate.

Dave in Houston