This is a very easy to use system for reattaching parts of plaster walls and ceilings that have started to separate from the lath behind. You just drill holes through the plaster, inject a treatment that softens the plaster, followed by adhesive, then use screws with plastic washers to push the softened plaster flat against the lath and hold in place while the adhesive hardens. Then you can remove the washers, and smooth the area and fill the holes with plaster or joint compound. I’ve used it several times over the past 2 years and have avoided having to remove and replace whole walls and ceilings. It can also be used to try to prevent cracks from growing.
I’ve probably spent about $100-200 per room of my house. It’s very easy to use, and helpful if you only have a few small problem areas, or just prefer to save an old plaster wall or ceiling during restoration or repair of an old house. They also sell patching plaster as well.