closetdoorsframing
Closets used to have full 8ft sliding doors. Converting to bifolds that are 6'8'' tall.
So I need to put in a header and frame it out to standard size.
The ceiling joists run perpendicular to the closet doorway.
Can I nail the header to the joists and call it good (since the header will only be bearing the weight of itself and the doors)
Or should I put in jack studs to help transfer weight to the foundation?
Use an angle grinder with a diamond blade. If you don't own one it's an inexpensive but very worthwhile investment.
International Residential Code 2012
Chapter 6 Wall Construction
Section R602 Wood Wall Framing
R602.7 Headers. For header spans see Tables R502.5(1) and R502.5(2).
So if you're on the top floor, you can use 2 2x4's (unless the building is 36' wide, in which case you'll need 2 2x6's). If you have a floor above, you'll need 2 2x6's (unless the building is 36' wide, in which case you'll need 2 2x8's).
Best Answer
I'd build a stub wall using construction screws (for better pullout strength), and I'd double the bottom plate. I'd then screw (not nail) to the joists through the top plate, and to the king studs through the ends. You wouldn't need to remove drywall on the ceiling if you use at least 3" screws.
This will carry drywall and trim just fine and will be laterally rigid enough for your purposes. Bifold doors don't normally hang on the header these days.
Note: If the ceiling drywall is mounted to something other than the ceiling joists, such as to sheet metal angles attached to the wall plates, this is to deal with seasonal truss lift. In that case you shouldn't hang your header from the ceiling joists as it'll possibly move on a seasonal basis, tearing up the drywall with it. You'd want to rest it on the wall using a conventional trimmer setup, and it'll need to be robust enough to span the opening without sagging.