I am planning to build a 24 X 26, gable entry, 2 car (double door) garage with a 12/12 roof pitch so I can use the loft area for a studio. My idea was to run a 26 foot girder down the center to support the ceiling joists. My question is, if I make a girder by sandwiching 2 X 12 lumber, "what is the maximum span without using intermediate posts for support?" I know it will depend on the anticipated load in the loft area so I would like to be on the safe side. Can I do this with 2X12 stock? Or would I be better off purchasing an engineered or prefabricated girder?

Thanks for your help!

You can definitely use 2x12 for a girder. The best way to go is a "built up" beam.

This is 2x12, 1/2 plywood, 2x12, 1/2 plywood, 2x12. You will sandwich the plywood between the 2x12's.

I'm assuming the beam will be 26' long. With that length post should be placed about every 9'.

If you go engineered or prefab, contact the manufacture for post placements.

Thanks Skiberger!!

You can definately use 2x12 for a girder. The best way to go is a "built up" beam.

This is 2x12, 1/2 plywood, 2x12, 1/2 plywood, 2x12. You will sandwich the plywood between the 2x12's.

I'm assuming the beam will be 26' long. With that length post should be placed about every 9'.

If you go engineered or prefab, contact the manufacture for post placements.



HI -
What about if the opening is 10' wide? I was thinking of using a 2 x 6 jack stud and 4 x 6 jack stud to hold up my 2 x 12 beam... you know, just like above?

This will not work, if you were to run just the girder itself with no load it will still sagg at 26ft
There would be a lot of bounce to that, a girder like that would need to be supported at least every 10ft and if you go by code it may be more than that. Easiest thing to do here is call you inspections office

My advise here is to look into using LVLs they are engineered ceiling or floor joist, this way you'd have no beam and no need of supports. There not as expensive as you may think
We've used these on many occasions