Hi everyone,
This is my first time on a forum such as this, so please bear with me.
I'm in the process of building a music studio using what is called the "room in a room"
technique where each room in the building has it's own walls and ceiling completely separate
from one another, the only common connection being the concrete slab floor. All walls are of 2x4 construction with 9' height. Two of the rooms are in the form of an "L", the vertical part of the L being approximately 25'x15' and the horizontal part of the L being approximately 16x10. Ceiling joist are run 16" OC from long wall to long wall in each room.
I'd like to leave the junction of these two rooms open to make one large L shaped room which would mean placing an 8' beam in the wall of the L vertical room where it goes past the 10' left end of the horizontal room, leaving about a foot on each end to support the beam.
This beam would have to support the 15' 2x8 YP ceiling joist, 2 layers of 5/8" sheetrock and some acoustical treatments of about 100 lb. The average weight of the joist are 40 lb. each and each layer of sheetrock is 2.5 lb/sq. ft.
My calculations are: 7 joist @ 40 lb. = 280 lb.
8'x16'=128 sq.ft.@5 lb. = 640 lb.
acoustical treatment @ 100 lb.
Total = 1020 lb. / 2 walls = 510 lb.
If this looks right to you, what size beam, or header? would be needed in a 2x4 wall to support 510 lb. safely? I'm hoping that 2 2x8's with plywood center will do it but I have my doubts.
Thanks for your help.
Bill

2- 2x8's with 1/2" ply spacer , glued and nailed together good should be more than enough, does not sound like you will have a lot of weight from above. Be sure to put a stud under the header on each side.

good luck Roger

Thanks Roger for the timely response to my question.

That's great. By using 2x8' for both the header and joist, it will give me a smooth ceiling and the header will not be seen.

Yes, the ends will be supported by 2 2x4 YP on each end.

Thanks again for the help.

Bill

I agree but would make that a double stud at each end. The double stud should be nailed to each other to prevent any bow once the small load is applied.

Ballengerb1,

Thanks for the conformation of Rogers reply. Having two experts in the field agree has a way of calming my fears of what could be a disaster if this thing were to come down.

Your advice is well taken and will be used.

You used the term "once the small load is applied". Would 500 lb. dead weight be considered a small load for a header such as this? What would you consider to be the upper limits of this header?

Once again thanks for the help and speedy answers. Also, thank you for the giving of your time and expertise to assist those of us who are not versed on such subjects.

May God bless and keep you safe,
Bill

500 lbs on a header is a very small load. It gets complex but most headers carry twice that load per foot. Calculating Loads on Headers and Beams - Publications - BM&WT - UMass Amherst