Suspended Concrete Floor

[Jeffrey R. Pope]

The flange, if placed at the bottom, would be in tension (as the web is now).

The tension is being placed on (we'll say) 3/8" of steel (the thickness of the web. Turned over, the tension would be on (we'll say) 6" of steel (the width of the flange).

The wide flange would offer much greater resistance than the thin web. I don't have a diagram, but maybe someone else can explain it better.

[sturetsky]

If you look at the beam, you will notice unused additional flanges for additional columns.

I don't care how long it's been there. This is a disaster waiting to happen, so stop jumping on it and don't walk under it.

I recently built a concrete roof/deck over my kitchen. 14' x !8' x 7" @ the thinnest point. 5000concrete. Cantilevered 48" past building. 1" & 3/4" coated rebar @6" o.c. 1" coated rebar @3" o.c. @ cantilever.

[Richard A. Hetzel]

The flange, if placed at the bottom, would be in tension (as the web is now).

The tension is being placed on (we'll say) 3/8" of steel (the thickness of the web. Turned over, the tension would be on (we'll say) 6" of steel (the width of the flange).

The wide flange would offer much greater resistance than the thin web. I don't have a diagram, but maybe someone else can explain it better.

Ahhh but the top of the tee would be in compression, and aside from bearing area issues, with the absence of a flange, the top of the inverted tee would be subject to buckling. When you see a concrete double-tee structure, which way are the tees? Tees, when used as beams (which is rare), are used with the flange on top, for a couple of reasons. And if those bottom plates were intended for columns, that would have been one heck of a thicket of columns down there. My guess is still that somebody got a "deal" on some used steel beams, and hoped they would work.

[afrost]

Originally Posted by cbrands

2 car garage over unfinished basement.

Pic 1:
2 6" steel beams running 21ft
1 screw column in the middle of each beam...neither column is anchored on either end.
ends of beams rest on foundation wall.
is there a problem with the bottom chords of the beams not being continuous???

Pic 2:
Between the top of the beam and the ceiling looked to be a fiberboard material.
It's only installed directly above the beams...rest of ceiling is concrete.
Possibly acting as a cushion???

Pic 3:
ceiling in corner of basement under garage...no, the pic is not playing with your eyes.
garage floor is bowing in this area.

Garage floor definately flexes and vibrates when you jump on it.

What's odd is that there was a hump all the way down the garage floor, but it was perpendicular to the beams.

Never ran into a suspended concrete garage floor like this.
Because of this and the factors listed above, I believe a Strucural Engineer is in order.

Any objections?...please share any input.

probably got a used beam, then cut it in half. there is no need for that filler piece above the beam but maybe when they formed it, they went right over the top flange and later cut it out - who knows.
those adjustable columns are scary!
a properly designed slab could span that 10 or 12', but it doesn't look like an engineer was consulted on this.
the hump might have been installed to shed water. plywood skirt is a good design for a garage, esp if it is kept up off the floor so that water doesn't wick up into it.

(i would refer to this as an elevated, not suspended, slab, but that doesn't mean my term is correct.)

defer to structural engineer.

[Kenton H. Shepard, CMI]

Looks to me like they ripped a big I-beam down the center with a torch, used the two halves in two different parts of the ceiling, then welded some plates on the bottom which were meant to bear on framed walls which never got installed or were removed at some point. Can't imagine an engineer putting his stamp on this one.

Recommend an SE

[Adam Thompson]

Looks like maybe they used full size uncut beams to begin with and then hit their head on the beam one to many times and decided to torch the darn thing. Any ways, did you end up fixing it or have an engineer look at it. any idea of what it would cost to do it properly?

[ldapkus]

Originally Posted by Adam Thompson

Looks like maybe they used full size uncut beams to begin with and then hit their head on the beam one to many times and decided to torch the darn thing. Any ways, did you end up fixing it or have an engineer look at it. any idea of what it would cost to do it properly?

Adam,
Where the hell have you been??? Chris has been waiting 8 months for your response so he can write his report.. Not friggin good...