I want to share a trick I learned for patching Sheetrock. I told this to several people at the MOM and no-one had ever heard of it. It works with any thickness of 'rock and is easy to do. If done correctly, you will never see the patch.
Let’s say you have a round hole about 3" in diameter - just about the size a door knob will make in a wall. Take a framing square and make it 4" x 4". It’s important to make the hole perfectly square. Then cut out a piece of 'rock anywhere from 6" x 6" up to 8" x 8". Now turn the piece over and you will be looking at the rear paper. Mark a 4" x 4" square in the middle of the back side of the piece of 'rock. Cut along the outline of the square but do not cut through the front paper. Scrape off the back paper and the white (or green) gypsum. Mud the wall and the back side of the front paper (you can also mud around the inside of the hole in the wall if you like) and press the patch firmly into position. Smooth the top paper out and then put on 2 or 3 coats of mud on top of the patch to feather the patch into the existing wall sanding between coats.
With practice, you can make the patch absolutely disappear. Use “hot” mud and the job can be completely done within 20 minutes although base and topping compound work just fine, too.
I learned this from a plastering contractor who worked on high-end homes. He made so much money doing patches that he only had to work 2or 3 days a week and he still owned a really nice home.
Let me know if something I wrote is not clear and I’ll try to explain it better. Hope this works for all of you. It certainly has made my life as a landlord easier.
One word of caution: This method is so easy and gives such good results that it’s easy to get carried away. It doesn’t work on really big holes where you need backing and sometimes, if there are lots of holes, it’s easier to simply replace an entire sheet of 'rock rather than try to patch it. It’s a judgement call you only learn from experience.