Ideally you should cut it so you expose a half a joist on two sides e g.
Patching ceiling around light fixture.
Patching the hole with drywall.
Trace the outline of the patch onto the ceiling around the hole.
Cut a piece of scrap wood that is 1 2 thinner than the opening to allow for the thickness of drywall.
Cut a square around the fixture using a utility knife scoring it repeatedly or a drywall saw being careful to avoid the wires.
Center the square patch over the hole and hold it against the ceiling.
Use the same thickness of drywall as the surrounding ceiling and cut the patch piece as close to the size of the hole as possible.
With its new trim in place the fixture should fit tight against the ceiling drywall with no gaps showing.
For small repairs on popcorn ceilings such as hairline cracks in ceiling dab on this stuff.
You ll also want to cut the piece a little smaller than the opening.
If you want to permanently patch the hole with drywall which is one option for covering the hole you.
The legs of the recessed light should extend over the new trim and onto the ceiling drywall.
Start with a light application let it dry and add more if needed.
Cut all the way back to the edges of the nearest joists on either side.
Cut a square of scrap drywall 1 2 in thick.
If you are not going to replace your old light fixture cover the hole with a piece of drywall for a permanent fix.
If the hole in the ceiling is 4 by 4 make your drywall scrap 6 by 6.
Use screws or adhesive to attach the scrap piece of wood to the framing piece.
With some careful brush work you can perfectly match the surrounding texture and easily cover minor cracks in ceiling.
In this video i demonstrate how to fill holes in the ceiling that have been exposed because light fixtures have been re positioned also you ll learn how to.
It s important to note whether the ceiling has a texture or a flat surface.
Rectangular holes are easier to patch than irregular ones so you must.
Mount the light fixture.
Cut out the hole in the ceiling to a square.
Install your light fixture with its new trim piece in the ceiling hole following the manufacterer s instructions.