These plaster washers are designed to pull the sagging plaster back snug with the lathe behind it. To use them, you should first locate the wall studs and mark their location on the wall. Also mark the location of any wiring and pipes so that you know what you need to work around.
Push the loose plaster back against the wall and secure two-inch screws through the plaster washers directly into the studs. You want the washers six to eight inches apart all around the loose area.
Once you're happy with how snug the plaster is, skim coat over the washers with some plaster patching compound. Use a nice wide taping knife to ensure a smooth repair. You'll need to let the compound dry completely and then recoat.
Once this drys, sand it down and then repaint. simple plaster repair in under ten dollars. You can't go wrong!
I'm Mrs. Fixit and it's just that simple!