I got these plans about a year ago (had to postpone our construction plans)
and I was immediately concerned about that span. I remember I looked it up
in the span tables and there is a grade of DF (not just No2 or better) that
will just support the 23ft span. But I'd rather not push this to its limit.
So I think I'm jgoing to do some redesign work, and break up the 23 foot
span with a beam and a post.

Just wanted to thank you guys for confirming this is a legitimate concern.
"wkearney99" wrote in message
t...
I have a set of architect drawn plans for a house. There's an A-Frame
section in the middle with vaulted ceiling (i.e. no 2nd floor) in the
front
and a 2nd floor loft in the back. The plans specify the use of 3x10s on
12"
centers. These would be 23ft long with no support other than at the
ends.
Seems to me that's pushing it a bit too far and the floor for the loft
will
be very spongy. Any thoughts?

Where are you going to find 3x10's? If anything you'd end up using
engineered wood I-beams. Even then that's an awfully wide span on which to
put a second floor.

Also, there is a bathroom in that loft and I really prefer to put down
ceramic tile. I'm concerned that a flor that has much deflection will
cause
grout joints to constantly crack.

You could potentially beef up the subfloor underneath the bathroom to
increase it's rigidity. Or you could add support columns underneath. But
otherwise, yeah, it's likely to end up with cracked grout.