I'm remodeling the ranch house and the ceiling in the living room is sagging. After tearing out sheetrock and loose fill insulation (talk about a mess), I discovered my ceiling joists were sagging. After further inspection, the original builders back in 1983 built a real hack job of a beam. Bottom-line is I need to build a structural beam to span 20 ft across a living room to help support the ceiling joists.

I've built beams over doorways but never this big. Will a 2 - 2" x 12" s with 1/2" plywood in the middle be stout enough for this project? I was thinking about making sure the scabs weren't opposing each other and to offset them. Screw everything and use liquid nails.

Any thoughts from experienced hands?

I would use an engineered wooden beam. I used them 20 years ago in my garage and shed. Ridge beams are 38’ and 26’. Also garage door headers.

I imagine my shed ridge would compare to your need and it’s bigger that a 4x12.

Home Depot asked a few questions then called a guy at supplier and he spec’ed the beam for me. It’s still straight.

call a real lumber yard and get a 4x12 laminated beam.
they are 2x4's laminated and glued, all i would use anymore.

20' holding joists (I assume they are split at the beam or hung on it?) carries a lot of weight, laminated beam could carry it easily.

you will need 3 of ya to hang it and be sure it is long enough to either sit over walls with cripple studs under it or metal posts. do it that way and never have another problem with sagging.

same thing cast did, might try home depot, I have always used lumber yards due to making large orders.

I don't what a weight difference would be I have used the 2x12 with 1/2 steel plate bolted. Like what you was thinking with plywood. We used the 2x12 with the plywood glued and nailed for a beam over 16 ft garage doors. If you use the2x12 make sure you stagger the splices,

Decided to build a beam myself. 22 ft long, made from (2) 2” x 12” that sandwich 1/2 plywood. Glued, nailed, and bolted. One heavy sob. Glad I made it in pieces.

That looks great. I bet it will do the job!

I removed a 12’ load bearing wall and opened a 5’ passage way in another load bearing wall for a friend of ours last weekend

Used two 2x12’s with plywood for the 12 foot wall and 2x10’s for the opening.

Worked like a charm.

That should do what you need. Did you put all the crowns up?

Oh yes! Got it installed today. Took all of the sag out of the ceiling.

Left old beam up. What could it hurt?

In last picture I would triple up the wall stud, the weight could cause the single one to start to bow. Just a suggestion.