ICF wall w/ 18 ft garage door header at gable end

[TroyD]

New ICF wall construction with 18 ft overhead garage door on the gable end. From the tables in 2020 IRC 608.8, it will need to be a steel beam header. Are there typical details and instructions for the steel beam pocket and anchorage to the 6" ICF wall below?

 

[jayrod12]

Are you engineering the entire house to meet the IRC, or if there's portions that are being designed to the IBC, couldn't you just design a 6" wide concrete beam?

I actually think the worse issue than vertical load is the wind load horizontally on that gable wall. It needs to span horizontally over that door a fair ways. And then at the door jambs you'll have a fair bit of concentrated wind load on that.

 

[dhengr]

TroyD:
I don’t think I’ve ever heard of or seen a 6” ICF system (Insulated Concrete Forms Sys.). There would be no room for any conc. or rebar btwn. the insul. face shells. Do you mean insulated precast tilt-up panels with conc. outer layers and insul. btwn. those layers? I would stl. frame two door jambs, from the found. to the roof diaphragm, with a stl. header btwn. the two jambs. Then, dress that up a little with some trim or detailing. Your biggest problems are going to be direct wind loading on that end wall and door frame, or getting that whole end wall to act properly as a shear wall for winds on the long sides. The precast panels on either side of the OH door should have some tie-down features at the found., which is designed accordingly. And, they should have some extra attachment pls. to the panels at each return corner into the long walls, to make those panels act as a unit. Otherwise, they will just rack up on one corner, like a rigid panel.

 

[phamENG]

dhengr - the 6" is the core dimension. Total thickness for a 6" ICF is usually just shy of 12".

I agree with jayrod - design it as a concrete beam. You may need to use deep beam design criteria because rebar placement can get tricky in those webs. If you stick with steel, then I'd just do it like any other steel beam to concrete wall connection. Given the tight quarters, you may consider welding studs onto the bottom flange of the beam and the contractor can set it in place and pour up to that level, encasing the studs. Then they can keep going up and around. Don't forget full height web stiffeners at the ends for lateral stability of your connection.

 

[TroyD]

Thank you for the good input! A concrete beam design makes more sense. The 18' opening exceeds the span table in the prescriptive table in IRC 608.8(9) for non-bearing walls, but I'm sure an engineered design is acceptable. If the contractor wishes, I can provide a steel beam option.

Thanks!