I'm having hard time thinking that's not feasible/adequate unless
there's a lot more going on here than a simple two-story. *What's he say
is the limiting criterion, deflection or loading (stress)?

We actually did not discuss the possibility of a 16 feet span with
steel plates only. So I can't say what his opinion is. But based on
his proposed solution, I figured he didn't think it was possible. I'll
have to chat with him to know for sure.


But, if the engineer's convinced the plate alone isn't enough, have a
lower flange welded to it -- either a wide leg angle or T. *In essence a
channel w/o the upper flange that you really don't have need for.

In the extreme, one could even go the "U" but that would surely seem
overkill (again unles....).

His proposed solution *is* a steel U. 40 inches long with 9 blots on
both ends. He says that a U is required due to the compression
constraints on top of the beam and the tension constraints on the
bottom. He seems to think that simply putting in plates is not
sufficient for proper support.

Keep in mind that the engineer is going with the safest solution here.
So it's probably somewhat overkill.


W/O actual loadings, drawings, etc., hard to say.

--

His proposed solution states that the columns (one a 4.5 feet and one
at 19.5 feet) both require material to support 25 000 pounds. So he
speced the columns as 5.25x5.5 PSL.

What other loads would you need to have a better idea? I can ask him
to give me the values.

It's true though that if the second column is at 16 feet instead of
20, then the first column might not be required if the steel U is
strong enough. I should've thought about that earlier!

Thanks again,
Phil