Patching and Plastering - replacing plaster over lath

This probably has been asked a thousand times, but...

I was pulling trim off a plaster/lath wall, and one of the nails loosened a large section of plaster. I ended up having to pull it off the lath. So, I'm left with about a 10 x 10 area of lath only. I want to repair it. What's the best way? I thought about using a piece of drywall over the lath, and then joint compound around the seams, but the plaster is only about 1/4 inch thick over the lath... maybe even less. Is there a product I can trowel in there and smooth out?

Thanks in advance for your help...

Brian

Since the plaster is so thin you need a strong mix. I would suggest a veneer plaster basecoat like Imperial basecoat by USG or mix your own with some RedTop gypsum plaster and sand. Use less sand than plaster by volume. This will give you strength. Clean out the spaces between the lath. (I am assuming you have wood lath.) If the lath cross studs use small screws and screw the lath to the studs. Paint the edges but not the face of the existing plaster with some bonding agent like PlasterWeld by Larsen's Products. There are other good brands. Mix the plaster to a consistency of oatmeal. Apply it by working it well into the lath and onto and behind the existing. Use the edge of a trowel or a straight stick and screed it off flush. Let this set until hard. It should take a few hours. I could tell you how to cut it back to leave room for a finish coat but I think you should use a setting type joint compound instead. It is more amateur friendly. Whatever you do don't let the base coat get fuller than what is there now. You must leave some room for the finish. If you use a setting type joint compound it might take more than one coat but you can recoat it as soon as one coat has set. You can sand it smooth if your walls are smooth or texture it to match.
Resist the temptation to just pile in some joint mud and call it good. It will shrink and crack on you and take a lot of coats. Patching plaster might work if you work quickly and still use the bonding agent on the joining. If you get some bonding agent on the lath that won't hurt. All our advice is worth what you pay for it. Let us know how it goes , we like a success story once in a while.

excellent. In case i cant find USG Imperial at my local home center, what other brand/type can I use? Gold Bond Kal-??

Thanks... I can't wait to try it!

Brian

Tightcoat is a pure plaster guy. (lol). You can find quick set drywall mud at any home center. It comes in a bag in powder form. It comes in 20, 45 and 90 min set up times. If I were you I would get 45. Mix up just enough to fill the space and fill. after that is set up put mesh tape over the entire filled area. Then put another coat of 45 over that making sure you feather out the edge. when that is set up put a top coat of regular light weight drywall mud over. Let set up for about an hour. Use a wet sponge to feather edges and smooth any high spots.

Brian,
Kal-Base. I forget its name exactly but you don't want finish.

Coops,
He asked and I told him. I suppose he will do it your way because he won't be able to find plaster.
Pity.