Existing ceiling joists can definitely be used but if you have removed the ceiling to install a new one this is a good opportunity to add blocking between the beams.
Installing wooden beams on ceiling.
Stretch a chalk line across the ceiling and snap it to keep lines even and to mark the necessary grids.
Use screws through the beam and into the blocks of wood on both sides of the beam and on all of the blocks of wood.
Hold plank up to outlet to make sure cut is in proper place.
The screws hold the beams in place while the glue dries.
Minimum of two screws per side.
Install nailers on the ceiling to make installing the faux beams easier.
Countersink the screws slightly.
Reinstall fixtures and turn power to room back on.
Spread heavy duty construction adhesive between the beams for extra strength.
Cut out marked area with a jig saw image 2.
Hold plank up to ceiling outlet and mark width and depth with a pencil image 1.
Install blocks every two feet and nail or screw them in place.
Repeat with other planks around outlets.
Cut the 2x4 lengths with a circular saw and install them between the joists flush with the bottom of the joist.
Nailers are thin strips of wood that the beam will fit over snugly.
Measure and mark the ceiling where you intend to install the beams.
Nail the first lvl to the joists then nail the second to the first and so on.