Plaster walls but no lath

My house was built in 1949 and I have plaster walls over some kind of wire mesh. Under that is the equivalant of modern sheetrock except it has preformed holes every 6" or so so the plaster could squish out and hold it tight to the wall. This must have been a transitional method of construction that happened as the use of lath fell out of favor but just before modern drywall construction (lucky me!!!). Anyway, can anyone help me understand this technique better and what was it called?? The wire mesh really makes repairs, forming new outlet box holes, etc. difficult. And the plaster makes hanging pictures, etc oh so much fun. -Jack

 

You are very fortunate to live in a superior house. it's too bad this kind of quality is not typical now adays.

The lath is gypsum lath It is 3/8" thick and the sheets are 48" X 16". The plaster is probably about 3/8" -1/2" thick. This is called plaster over gypsum lath. it is also called RockLath but that is a brand or button board because of the buttons formed when the plaster was pushed through the holes.

Is the mesh woven wire of about 20 gauge with 1" mesh (rarely 17ga 1 1/2" mesh)?

Or do you have metal lath? Which is mesh of about 3/8" X 1/2" and formed of expanded metal?

I don't know why you are troubled by the mesh. Cut it carefully. It's messy but to cut holes use an abrasive circular blade which will cut through the plaster, the lath and the mesh and leave a nice smooth edge.

For hanging pictures use a masonry bit to drill the hole and wall anchors just like for drywall unless you hit a stud.

What part of the country are you in?
Is the wire mesh everywhere or only in angles and above and below the corners of doors and windows?

Do you have cracks that bother you?

You seem to think that somehow this is inferior to more modern (read cheaper, thinner, less soundproof, softer) drywall. It isn't.

 

I once lived in a house with the same construction.I found that the new type of picture hangers with very sharp hardened nails (several brands make them) worked well if you tapped the nails in carefully.The house would have withstood a tornado.It was like a fortress but the wire mesh played havoc with any type of signal like a radio etc.

I agree with the previous post concerning dealing with the walls.Also it turns out that you may find the studs not 16 in on center but I think that varies from house to house.

 

I've been researching the button board & plaster ceilings/walls that are in my 1949 house and have new respect for the quality of the materials. The mesh I mentioned is not metal lath but 20 gauge 1" mesh...more like chicken wire. And I don't know yet if it is over the entire surface or just in corners.

Anyway, I need to repair a couple of ceiling spots that are 2'X2' in size. Can I carefully cut out the section and shim the joists and use modern sheetrock as a patch using tape and joint compound?? I had to rehang the entire ceiling. Also, would it be best to cut away the button board flush with a ceiling joist and then scab in a 2X4 alongside the existing joist for a nailing surface. Seems like that would produce the least trauma on the remaining plaster ceiling?

Finally, what is the best tool to use to cut outlet holes, etc in the plaster/button board. Is there a blade specifically designed for my sawzall or jigsaw. Maybe I should invest in a more appropriate tool? Thanks for any and all help.

 

Yes you can replace the material in the opening with sheetrock. It's inferior but you can do it. If you are dead set on doing it yourself this is probably more amateur friendly than plaster.

I can actually do it with plaster faster than I can with drywall and it fits perfectly when finished but that's just me. Leave the drywall just a little bit shy of flush. It easier to fill the drywall to make a flat patch than to feather our onto the painted plaster.
You are right about cutting the lath and plaster flush to the joist or stud and adding a nailer. Screw the nailer to the joist or stud rather than nailing it. it will jar the rest of the wall or ceiling less.

A RotoZip tool with a plaster cutting bit will do the best job on the outlets. I suppose the bits are carbide of some kind.

They make abrasive blades for jig saws and sawsalls. They will probably do a good job on the outlets. I've never tried it. It's the combination of metal reinforcing and gypsum lath and plaster that complicates this cut. Otherwise you could use a utility knife. It might take a few blades but they are cheap.

Keep us informed.

 

I am often participating in more than one thread but I have trouble locating the threads and need to remind myself to check threads for replies. Isn't there a way for me to receive an e-mail notification that someone has replied? I'm guessing I'm not using this forum correctly. Can anyone advise me? Thanks.

 

If I remember corectly, go to the top bar on this page and click on thread tools, then click subscribe to this thread - that should give you an e-mail notification when a post has been added to this thread.