Replies

1. 
   Shep | Dec 09, 2007 04:51pm | #1

   I generally use perlited gypsum plaster for the first coat, especially on larger repairs. It sets up quickly, and fills the larger gaps without shrinking much. The 2 big brand names are Gypsolite and Structolite. I think its only available in 50 (maybe its 60)pound bags. Store any unused plaster in a clean drywall bucket with the lid on tight, and it'll last for years.

   Make sure you either dampen the repair area, or better yet, use a bonding agent. It helps keep the old plaster from sucking the moisture out of the new.

   Leave the brown coat a little shy of the finished surface to allow for the top coat. I like using a setting compound like EasySand 45, so I can recoat pretty quickly, and do any sanding, if necessary. But I have used joint compound, too.

   BTW, a lathe is a machine for turning. Lath is the wood strips <G>

1. 
   mainejohn | Dec 09, 2007 04:58pm | #2

   shep, thanks for the advice! here's another question: have you tried the plaster button screws for securing loose sections to the lath? (see, i got it right!) thanks.

1. 
   Shep | Dec 09, 2007 08:27pm | #3

   Yup, I've used them. They do a good job.

   I like to countersink them just a little bit, so I can skim coat right over them without building up the plaster too much.

   I use a spade bit, and JUST break the surface of the plaster. You'll get a feel for it pretty quick.

1. 
   mainejohn | Dec 09, 2007 08:41pm | #4

   thanks again shep. i really appreciate the tips... never repaired lath and plaster before, only ripped it off and drywalled instead. signing off, john.

1. 
   Shep | Dec 09, 2007 08:48pm | #5

   Oh, yeah- drywall.

   On big patches, I'll sometimes fit a piece of drywall in the hole, then tape and spackle it. Use rock that matches your plaster thickness- 3/8" is usually close.

   Its better to use rock that's a bit thinner. It can be shimmed with 15# or 30# tar paper to line up with  the face of the plaster.

2. 
   rez | Dec 09, 2007 08:49pm | #6

   ya, and make sure the spade bit doesn't have a tooth on the outer sides of the blade.

    Don't ask be how I know this. 

2. 
   rez | Dec 09, 2007 08:55pm | #7

   Watch for any small bits of plaster that may have fallen down between the lath and the plaster you are trying to secure

   as it may prevent a tight refit of the plaster wall to the lath and leave a hump at best.

   Shep- You ever inject a glue between the plaster and lath or use the webbed fiberglass sheeting?  

1. 
   Jer | Dec 09, 2007 09:43pm | #8

   When the plaster keys are knocked off behind the lath but the finish plaster wall is still in good shape, that's the time to inject glue between the lath & plaster. You have to drill a lot of holes into the wood lath and it's better and easier to do it from the back of the wall if you can get to it. The drilled holes should stop when they get to the depth of where the plaster and wood meet. When you inject, do it slowly and there will be a capillary type action where the glue will flow between the wood & plaster. There are glues specifically made for this process but I have used Plasterweldt and it does the same thing. Another thing you can do if you can get to the back of the wall where all the keys are knocked off is to shop vac it down, paint on some bonding agent, and back plaster where the keys used to be.I used the fiberglass mesh in wide rolls (three feet), and lines entire rooms in it and then skim coated it. That's for when the plaster is crazed and cracked with hairline fractures everywhere, but it's still strong and you don't want to go through the mess of demolition and then the task of truing up the framing to accept sheetrock.

1. 
   rez | Dec 09, 2007 10:08pm | #9

   Thanks,

   Sounds more like highend jobs where the clients would want restoration precision instead of just prettying something up.

    

   Is the ShewrinWilliams Bonding Primer equal to a PlasterWeld for total wall coverage before a skimcoat?? 

2. 
   Shep | Dec 10, 2007 01:32am | #10

   I'm familiar with both the fiberglass sheets, and glueing the plaster back, but haven't done either myself.

   Using the fiberglass seems waay to much like wallpapering. And I hate wallpapering. If things are that bad, I prefer to sub it out to someone who's faster than I.

   Unfortunately, the guy I used to get is retired. So I might have to get dirty the next time.

1. 
   Jer | Dec 10, 2007 04:39am | #11

   It's exactly like wallpapering and it's a PITA. It works though. Last one I did was a 150 YO farm house right on the shores of the Delaware outside of Belvedere just south of the Water Gap. Even with all the skimming I did, the walls still maintained their waviness and out of square look which was actually good. Floors were 16" wide pumpkin pine, I lightly sanded and finished those as well. The place was quite beautiful when it was finished.

2. 
   Learner | Dec 10, 2007 08:44am | #12

   I've used ceiling cement with good results. It is a combination of compound, cement and fiberglass fibers. It can fill quite large spaces and the fibers help to give it strength.