What size beam is necessary to carry sheetrock ceiling. The beam will run perpendicular to the rafters and parallel with the roof ridge beam - 24 feet long and will only carry weight of ceiling sheetrock. I intend to use 2X12 inch lumber for beam. Any help in how to constructing this beam will be greatly appreciated. Neebie from Mobile, AL

 

Welcome to the forums!

Any reason your not using trusses? They will give you a clear span with no beam.

 

Maybe he wants to use the attic space for storage of light-weight items. Which trusses would make a bit difficult.

 

There are truss designs which allow more flexibility for use of the attic space.

 

"Carry only weight of sheetrock"...and we know how that goes. I would use trusses,too. Cheaper, precision made, strong. Only allow scuttle for firefighters per code.

 

Another vote for trusses. Almost every city of any size has a truss plant nearby, I'm sure there is one near you. If you buy direct from them it will probably be cheaper than your 2x12 beam.

 

If attic space is what the OP wants then they can look into storage trusses.

 

Said specifically to hold sheetrock only. I would graduate to triple 11 1/4" LVL and take off from flush bottom with 2x8 ceiling joists and joist hangers on all ends or plate rest.