I Have A Question About Repairing Plaster Walls.

Factual Questions
1

Short story. I live in a very old house that I am rennovating. The walls are all plaster. Most of the plaster has degraded to the point where one can punch through a wall and grab a handful of plaster dust on the way out. In the rooms where an entire wall has to be replaced, I’ve been using Blue Board and plastering over top of that. But where only a small hole has to be replastered, I’ve been applying the plaster right over the old lathing, with excellent results.

Yes, I prefer to use plaster. I’m a glutton for punishment.

Over time, I have actually become pretty good at using plaster. I’m very impressed with the results. And no one can convince me that drywall, or even the plaster skim coated drywall that you can buy, is stronger or more durable than plaster.

But, there are a few sections in the house where the lather had to be removed to accomdate new wires, outlets, etc. The whole wall doesn’t have to be replaced, and since the lathing was removed, I cannot just replaster.

These holes are usually odd in shape and size, which would make patching the hole with more Blue Board and plaster difficult, but not impossible.

I guess I could take my reciprocating saw and make the holes an even geometrical shape, but I discovered something in one of the walls.

Sometime in the history of this house, someone was doing some plaster repair, just as I am doing now. In more than one wall that I’ve punched through, I’ve found, in lieu of lathing, a weird metal type of sheeting that was holding the plaster in place - presumably while it dried and hardened.

This metal sheeting is somewhere in between chicken coop wire and a heating vent cover. It is a thin metal sheeting, maybe 20 to 22 AWG equivalent, that has tiny perforations punched in it, and it is ridged, like one of those old time washboards.

My questions are:

What is this stuff called?

Is it still manufactured and available for use?

Where can I get some, since the common retail places do not seem to carry it?

2

It’s called metal lath; look for it on Google. I’m not sure that it’s really the answer to your problem, though-- I’ve never worked with it, but it looks ornery.

3

It’s called metal lath and surprising that you can’t find it anywhere. Try calling your local contractor’s supply house (for construction workers, not Ace hardware). If you get stuck, www.thebluebook.com.

The metal lath is typically used in modern construction rather than the expensive and time-consuming wood lath that, if it breaks, is an absolute pain to fix. The metal is significantly stronger.

4

I don’t think the big box stores have it. I’ve always purchased it from masonry supply houses, where I’d buy stucco and related products.

5

Oh yuck. The closest place to me, where I can purchase it, is in Ohio.

Why isn’t this stuff more readily available?

6

Go to www.anywho.com and enter masonry under the business category. I just checked using Pittsburgh for the city, and found three listings under ‘Masonry Equipment & Supplies’.

7

The way I’ve done it in the past, mind you I was patching gyprock sheets (I assume this is what you call drywall), is to glue the patch sheet to the back of the existing wall and plaster in the gap. For a square hole I cut a rectangular piece that is inserted at an angle then turned so that it fills the hole and extends either side. The face has been previously glued (Hard-as-Nails) and a screw inserted in the centre for manouvering. For bigger holes I have built up the patch bit by bit. After the glue dries plaster the 1/2" deep hole, remove the screw if it seems solid and cover that last spot and you’re done. When we moved into our first place we changed the power points in nearly every room so I had lots of little rectangulas patches to do and they’re invisible.

8

Other names for metal lath include diamond lath and mesh lath. Depending on where you live, one name may be more common than the others. Its all the same stuff.

9

You can actually use chicken coop wire. Just fold it over to give closer spacing. For small patches anyways.

I like to scrape back (or sand) a couple of inches from the edge of the hole, fill it in almost to the surface, let it set, then come back and finish it out, retexturing as it needs.

I love plaster work. I wish more people would keep it in good repair.

10

For a really old house, you might want to check with your local or state Historical Commission to see if the plaster you are using is compatible with the existing plaster. As a general rule the contemporary materials are much harder than the old stuff and this can create probles over the years as the walls move with the seasons.

Shameless plug for my old house project.

11

You can buy the plastic version in the big box stores. I usually find it next to the tile section. Lowes carries it in 2’x20’ rolls, usually blue in color. Has a little more flex than the metal stuff but nothing you can’t deal with.

You can soften plaster by adding gypsum powder, the type used to line athletic fields. Check codes first like the other builders here have hinted.

12

You know what? I braved the blizzard we had today to go to Home Depot. They actually had it in stock. I had to ask three different people, “Metal lathing? Does that actually exist?” but it was in a corner underneath the cement mixes. Pretty cheap, too.