Phil wrote:
On Jun 22, 11:38 am, dpb wrote:
....

Alternate suggestion -- instead of trying to replace the whole thing,
why not ask what it would take in a steel plate bolted alongside the
existing beam to get the span? (I'd guess 1/2" would do it, but I
didn't try any calc's, that's just gut feel).
....

That's Plan A, or close to it at least. The steel plate has been
speced-out and requires some, as you say, judiciously placed brackets
for the joists. The downside is that the engineer didn't seem to think
that I could get the 16 feet span using this. When we discussed this
plan, we immediatly thought we needed to place the basement columns
under the gound-floor columns to get proper support. You're right
though, I should get him to check if we can get a 16 feet span using
the steel plates solution.
....

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)?

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....).

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

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