Link was down. Sounds like you have some of the first (scratch) coat exposed. If this is not keyed to the lath anymore you need to remove it. There's a product called Structolite you can use to fill in these areas. Keep it below the surface of the white top coat by about 1/8" After it's dry(follow instructions on bag) you can top coat it with plaster or compound or a mixture of the two. Pure plaster sets up in a heartbeat. There's a product you can put in to slow the process a bit, I think lime, but I don't remember. I just mix up some plaster and add some compound into it and it works for me. Plaster does not sand well at all. Better to get it smooth as you apply it. They also sell compound that sets up in varying intervals. Thirty, forty five and ninety minutes. Most, if not all, are available at a masonary supply store. When the pictures are available I'll check them out. Ron

The raw materials needed to repair plaster walls & ceilings are relatively inexpensive, less than $200.00 per room. You would need basecoat plaster for the first layer, and a mix of gauging plaster, finish lime, and retarder, for the top coat. It is easy enough for a beginner to do a small repair, say one foot diameter. However, getting good results on an entire wall or ceiling comes with experience. How extensive are your repairs?

You say that the drywall is breaking down. It normally won't break down unless it has gotten damp or wet. I think before you cover anything up you should determine if there is a problem. If there is correct if first. The plaster loosening up is fairly common. It could be for a number of reason, but I think you should still be sure that there isn't moisture problem there too. As far as covering the existing walls without removing the old stuff.....I have personlly covered I would guess 40 or 50 rooms and ceilings over the years without tearing out the old stuff. Is there insulation in the walls and will you ever need it there? Celulose can be blown in from the inside and, of course, that would be done first. If the walls aren't in too bad of shape I go over everything with 3/8" drywall and use lots of screws. Where you are going over plaster and lathe you will sometimes hit studs, but often just the lathe. The screws into the lathe will hold as long as you use lots of screws. Over the drywall you will have to locate and hit the studs with screws. Also on going over the drywall, you will have to end the pieces over a stud just as if you were applying it to bare studded walls. If you end it between studs there will be nothing to hold the edges and the job will be ruined. When I go over existing walls I make sure that any wiring that might be needed is done first. If necessary I make holes to run wire. If there are any real uneven spots on the wall I shim out the low spots with scrap pieces of 1/4" or 1/8" luan or paneling. I don't remove the door and window casings or the baseboards. I run the drywall right up against the casing and fill in any gaps with mud when I am taping. Now a lot of remodelers won't agree with going ovre the existing, but I've never had a problem as long as I've used plenty of screws that are long enough to penetrate the drywall or the plaster. If the walls or ceilings are terribly uneven you might have to use 1/2", but I've always used 3/8".

Hi, I've patched just a few plaster walls. My goal was to cover the hole and make it look good. 3x7 is a small patch. This is how I would do it. Cut a piece of sheetrock 5x9 (thickness isn't important). Score the back of the 9x5 piece 1 inch all around then break the 1 inch piece off the back then peel the 1 inch piece off the front paper. You should now have a piece that is 3x7 on the back and 9x5 on the front. Fit the patch to the hole . It may take some scraping you don't want it too tight. Spread some mud on the edge of the hole and patch and the paper on the patch. Set it in the hole a use a 4 inch blade to set the patch. Let it dry. Most times the patch will be a little lower than the original surface let the patch dry finish as needed. Good Luck Woodbutcher