Walls and Ceilings - How do I patch drywall holes made by plumber?

I had a slab hot water leak repaired yesterday. The plumber had to cut out 3 square/rectangular holes in the drywall to get at the pipe manifolds.

This plumber does not patch the holes he makes in the drywall. He recommends another contractor to do this.

I think I would like to close the drywall openings myself. I still have the square pieces the plumber cut out. Does anyone have the procedure to do this?. Or can someone maybe send a hyperlink of a step-by-step procedure with photos?

Thanks,
Dave

A quick easy method is to use constructin adhesive (glue) and screw wood strips to the all of the inside corners of each opening. When installed on the diagonal, the wood will give you something to seat against. Paint stirers work exceptionally well and their cheap Glue the sticks where they will be secured to the inside of the wall board. Screw through the wall board into the sticks Give the glue a little chance to set up because when you apply pressure when mounting the replacement piece onto the sticks you don't want dislodge the sticks. The glue will add an enormous amount of strength.

Tape spackle and paint

Good Luck

You can insert a piece of wood [longer than hole] into the hole and secure both ends with a drywall screw. Then you can screw the patch piece into the that piece if wood. A large hole might require more than one piece of wood. I've used both 1x's and plywood for this purpose.

Once the hole is plugged you need to use drywall tape and joint compound to finish the repair. Cut pieces of tape to cover the gap/seem between the repair and existing wall. Apply j/c and then embed the tape in the j/c. Rake off all excess mud with a broad knife - this will also smooth it out. It usually takes 3 coats of mud, sand as needed.