# Matching drywall to plaster



## paintdrying (Jul 13, 2012)

Some newbie questions here.
Let us just say I wanted to keep something original, so I remove a section of plaster and the wooden lathe behind it, down to the bare studs. 

So I do this in maybe a 2' x 2' area in a ceiling. So, now I want to return new wooden lathe and plaster back over it as was originally done. My first question is, can I float it out with drywall compound or is their a special plaster mix I need to use. Is it done in layers or one coat. 

Is that wire mesh the easiest way to do it. Next question,so I repair this same 2x2 section of plaster but instead decide to just nail in a piece of drywall.
I use some shims and now the drywall is even on one side but the other side the drywall is lower than the plaster, do I keep adjusting all the shims untill everything is perfectly even or do I just float it out. I am looking for fastest easiest way to do this.


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## oh'mike (Sep 18, 2009)

Skip the wood lath---that must be coated with real plaster--scratch coat and finish plaster--

Add drywall with furring strips---then multiple coat of powdered easy sand---feather it out well--

You may wish to use 'light weight' blue lid for the final coat--it is much softer and easier to sand than the powdered mix---


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## paintdrying (Jul 13, 2012)

I looked into the real plaster mixes and they are very $$$$. So after I set the new drywall I would need to prime the old plaster as well as the new drywall? I would approach the joints as I would drywall to drywall? How much of a height difference between the pieces is acceptable? My fear is trying to use that easy sand as a skim coat. Possibly having problems with the easy sand sticking to the old plaster. Never used the blue lid, maybe I could try that for a final coat.


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## oh'mike (Sep 18, 2009)

No need to prime--simply scuff sand the painted plaster---it will stick just fine---priming will not hurt--so if you have primer handy go ahead---


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## Master Brian (Apr 24, 2009)

I don't know about a 2' x 2' area, but I have patched many cracks in my c1915 house and so far 5yrs later I haven't seen any signs of them failing, yet I have seen other peoples fail in that amount of time, so I must be doing something sort of right! 

I basically saw a T.O.H., or similar show, using Big Walley's Plaster Magic, so I gave it a try. I liked it a lot, but it was too expensive for my budget no further than it allowed me to go. I ended up using basically the same method, of drilling holes into the plaster along where a crack is and then I shoot liquid nails into the hole and use a drywall screw along with a plastic washer to suck the plaster back to the lathe. After a day or so, I take the screw/washer back out and fill the crack with approx 80/20 mix of plaster of paris/joint compound. Once that dries, I finish off with joint compound to get it smooth. 

I realize you are working a larger section and I'm sure the drywall method would work great, but I have actually floated pretty large voids with my method. Of course, over the larger ones, the screws/liquid nails are only used to re-inforce the perimeter of those sections. As I type I've been working on a cracked out area where I'm down to just the base coat and some exposed lathe with a surface area of about 2sqft and so far it feels very solid.

FWIW, the addition of a small bit of joint compound allows the plaster to flow much nicer, yet it's not enough to cause cracking or much, if any, shrinking. I also don't tape the crack as the videos they put out don't show doing that either and I don't want to fight the tape seem. My reason for liquid nails is any time I've ever seen wood glued to concrete, it's either the wood or the concrete that fails, never the joint and it's a forced seperation!

Not sure if this helps for your current needs, but maybe in a future repair if not! If nothing else, maybe you could use the plaster mixed with joint compound to float the two together!? Good luck!!


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