This repair is continued from Part 2.
Drywall Repair Panel
I purchased a 2ft x 2ft x 1/2in drywall panel for ~$4 and marked a 6in by 6.5in square in the corner to fit the hole I cut in the basement ceiling. (If you have a scrap piece of drywall laying about, that will also do fine.) The curve in the bottom edge of the panel in this photo is a fisheye artifact from the camera lens.
Fitting the Drywall Patch Panel
Here’s the new repair panel compared to the water damaged drywall section cut from the ceiling. I used a sawzall blade to the cut the panel because it has finer saw teeth for a cleaner cut.
The drywall repair panel is trimmed to fit with the utility knife and fastened with four drywall screws to the plywood backer board and the metal runner of the suspended ceiling.
Tape and Mud the Drywall Joints
Self-adhesive fiberglass drywall joint tape is applied to the four joints of the repair panel. A thin coat of joint compound applied with a 4″ or 6″ blade. Click on the photo for a larger version. If you look closely, you can see the weave of the fiberglass tape.
I forgot to take a photo of the fiberglass joint tape before I applied joint compound to the ceiling. This next photo illustrates the process from a job I was doing on the wall.
Apply Finish Coats of Joint Compound
Immediately after the fiberglass tape joints are mudded (“mud” is slang for drywall joint compound), spread a thin coat of drywall compound using the 12-inch blade, feathering the edges. Don’t delay because those feather thin layers of mud start to dry in minutes and will gum up the blade leaving long tracks in the finish.
Tip: With drywall compound, “less is more“. The less you spread on the less sanding you’ll have to do later.
The next photo is the ceiling patch after the first application of drywall compound with the 12 inch blade. I left this to dry overnight before sanding.
Drywall Wet Sanding
The next day, I used a wet sanding sponge to smooth the high spots and feather the repair into the main ceiling. A drywall sanding sponge is a sponge made with an abrasive surface. Dip the sponge in a bucket of water, squeeze out the excess water so it’s damp, and sand with almost no dust. Rinse the sponge in water as needed to remove the joint compound that will clog up the sanding surface.
After sanding, I applied a very thin second coat of joint compound with the 12 inch blade, let dry and wet sanded. Here’s the ceiling patch ready to be painted. The nearly white-on-white doesn’t contrast well for the camera.
If you look closely (click on the photo for a larger view) you can see the brighter edges of the new paint where I painted the ceiling patch. I took a small sample of the ceiling to the local paint store for a computer color match, but as the salesman explained, the computer isn’t perfect and whites are especially hard to make an exact color match.
I hope this project saves you some money!
Take care,
Bob Jackson
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Great article! I have seen and repaired a ton of water damaged drywall! With regards to sanding, make sure you don’t over sand the repair area. As stated in the article, you want to sand to smooth the high spots. You are not trying to remove all the low spots (imperfections) at this point. Only to feather and get a generally flat surface to put the final coat on. You will see a lot of imperfections when you are done sanding, before the final coat of mud is applied. If you are sanding the area smooth before the second coat, it will be very difficult to get an overall transparent repair when you are finished.
Good luck in all your repairs!
I have a double garage that is totally sheet rocked. A couple of years ago I replaced my roof and the night before I finished the section over my garage it came a terrible rain storm in which I had leaks all over the garage ceiling. Now all the joint compound & tape in the ceiling are falling out, and there are several pieces that need to be resecured to the ceiling. Its a mess!!! Got any advice on how to best repair the ceiling and save the sheet rock?
The sheetrock paper face is most likely delaminated on the backside. Once that happens the gypsum crumbles and the drywall loses it’s strength. I would pull it all off and hang new drywall – it’s a pain but not very expensive. Call around for a couple of bids, the construction industry is still hurting and the bids should be very competitive.
You other option is to cut out the worst sections following the lines of the ceiling joists and install new sections of drywall. If it’s as bad as your describe, you may decide to replace the entire ceiling.