20 ft clearspan

[matt_i]

No inspector is residential construction gets down to, nor are houses built to that level of detail.

Every single house uses some amount of steel beams to support the first floor.

We measure the pockets after the walls are poured, and order our beams 1.5” less then that distance. Beams usually require 4” of bearing area on concrete walls, and our pockets are 6” deep so we have plenty of leeway.

And the connections, all we do is use a 2x6 laid flat, with 16d sinkers Nailed in the end an inch and hammered down and around the beam. Then your joists rest on top of that and are toenailed to the wood. There’s no fancy connections. If your doing a flush beam, it’s the same thing. There’s hangers that get nailed over the top of the flat wood and hang down to hold the joists

Agreed on the concrete pocket, shim with steel to level. Fairly easy and never going to develop creep or defects like drying wood can.

But this is suspended - overhead and (apparently) no pre-planned foundation to put it on other than the concrete floor. So now its got legs...Steel legs? Wood legs? None of those go on with 16ds. And wood joists attaching to the steel header? How to attach? Easy is to set them on the top flange but now there's no full bracing unless the joists overhang enough to wrap the 16ds, and the depth is effectively doubled for the floor support system (when looking at the edge). Trying to make it a "thick plane"....which it sounded like the O.P. was after in going steel in the first place, requires joist hangers or the like...which again don't go in with 16ds or the Simpson nails/hex screws....its surely my opinion but I thoroughly believe the LVLs are the sweet spot when it comes to cost + ease of fabrication.

 

[Diesel Dan]

The wall the one end is going to be sitting on top of needs to have a full foundation underneath it, not just a 4"-6" concrete floor. A header/ledger attached the the other wall not adequate. That ledger needs supports going down to a foundation.

You just described my entire second floor support structure.
The perimeter walls of the shouse are on footers but the interior wall separating the shop/house is sitting on "just" a 5-6" slab and other end a ledger board.

I imagine he has some type of footer since every state requires some type for anything bigger than a shed. A building with a 20’ span is definitely big enough.

I'm still amazed how many barns are still built without proper sized post footers. My last 30x40 had 24" dia x 12" site poured discs per code.

 

[mcbane]

The wall the one end is going to be sitting on top of needs to have a full foundation underneath it, not just a 4"-6" concrete floor. A header/ledger attached the the other wall not adequate. That ledger needs supports going down to a foundation.

+1

If your 5” slab is properly reinforced and bearing on a stiff sub base you might be ok for a strip load at 500 plf. Ask an engineer to review. Heavier slabs provide a great deal of flexibility for future mezzanines or pallet racks. The only downside is if you admit to greater than 6” slab some knucklehead will say you are wasting money.


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[Diesel Dan]

This is what the truss engineer proposed and building inspector signed off on.

The wall is anchored to the slab.

 

[GMCGarage]

Weyerhaueser can resaw a 3.5” to a 1.75”. They have tables for them and yes they are special order. But it’s also the only way to get a treated structural wood beam for exterior use as well.

To just blanket say ‘wrong’ is ignorant just because he’s never seen or specd them before

I know. Sometimes people have to be educated on here. I have used that size before in a design.

 

[GMCGarage]

This is what the truss engineer proposed and building inspector signed off on.

The wall is anchored to the slab.

Nothing wrong with that if designed properly. two story houses pre-50's were all ledger supported usually, due to the balloon framing.

 

[scottydosnntkno]

This is what the truss engineer proposed and building inspector signed off on.

The wall is anchored to the slab.

Ledgers are perfectly fine as long as you use proper structural bolts which clearly you did. You can’t just nail a board to the side of a stud and call it good, it has to be properly designed

 

[C91x]

Use the PLF loads off this chart https://parr.com/PDFs/LP LVL 1.9E.pdf