Any carpenters here? (installing a handrail)

[Father Haskell]

By eye. The studs might be high enough that you can see them against a back light. A desk lamp is the only tool you need.

[Greg Guarino]

Funny thing. That idea occurred to me today while I was thinking about something else. Delays really do increase the efficiency of my work sometimes. I am seriously considering using this method.

Swingman suggested a 1/16" bit to find the studs. But I'm worried that I may not have a sensitive enough "feel" for when I've hit a stud with such a small bit and through thick plaster and wood lath. But a decorative board to cover the holes seems pretty foolproof, which is exactly the sort of method I need. Thanks.

[Greg Guarino]

It's two stories, but is actually brick, attached on both sides.

OK. I doubted that a stud finder would work well in this type of wall anyway.

Yup. That is the most important factor, but my Mom will prefer that it look nice too.

[Greg Guarino]

I figure to get three or four studs; it's a very short run of stairs. And yes, I'll be a lot happier if I get a nice long screw to groan it's way in all the way.

[clare]

Drill with the 1/16 bit. 2 inched max depth. Sound the holes with a

3" pin. If it stops at 2", you are in a stud. If it goes farther than 2", you are not.

[FrozenNorth]

Yep, put a piece of masking tape on your drill bit at the two inch mark, plaster/metal lathe house here, with the metal the stud sensor is absolutely useless..

[clare]

Depends on the sensor. I have one that is adjustable for wall density and it will pick up a 2X4 block on the back of a 2X4.. Adjusts for 1/2", 1" or 1 1/2" thick plaster walls. Doesn't really care too much about metal lath. Made by (or for) Stanley

[Lew Hodgett]

------------------------------------------------------ To expand on Leon's idea a bit, the object is to provide a secure railing to a plastered wall with unknown stud locations.

Rather than use a 1x4, use a 1x8 oak board attached to the wall with two rows of 1/4" molly boats on 8" centers.

The board provides the structure to mount the rail while also spreading the rail load across a larger surface thus reducing the load any specific molly carries.

Lew

[WW]

Shop:

I figure to get three or four studs; it's a very short run of stairs. And yes, I'll be a lot happier if I get a nice long screw to groan it's way in all the way.

Greg...Wax the screws and the go in easy. WW

[WW]

Drill with the 1/16 bit. 2 inched max depth. Sound the holes with a

3" pin. If it stops at 2", you are in a stud. If it goes farther than 2", you are not.

Brilliant idea. I may find this for use sometime. WW

[Greg Guarino]

I agree. Simple and sure. I'll try it.

[tdacon]

Anyway, I have no experience finding studs in that kind of construction. The walls are too rigid for me to just sound them out with my fist. I don't own a stud finder, but I might buy one if it's of any use in that kind of wall. I'm not eager to drill a series of holes that I'll need to repair, and then match the paint.

If you want to go looking for studs, here's the stud finder you want to use.

Makes a tiny hole, less than 1/32 in diameter, that you can fill with a little smear of toothpaste, or just leave if it's in an inconspicuous place. Never needs batteries :-)

Tom

[Larry Jaques]

My 1939 California bungalow in Vista was built using full 2" x 3" rough sawn cedar and redwood studs on 24" centers. It also had knob and tube wiring which looked like a busy Union Telegraph Center in the attic. 1/4" ply topped the studs for the walls and ceilings, and the floor was full 1" thick by 4" (or 5"?) wide pineywood.

In demos, I've seen plaster over chicken wire, plaster over lath, and plaster over chicken wire over lath, but all had studs behind them. I think most were built 24" OC and built before WWII. Lath is spaced to provide a place for the plaster to overflow behind it and lock it to the wood. I haven't seen your holey lath before.

[Larry Jaques]

I always drill pilot holes for railing hardware rather than risk a screw breaking at the wrong time.

[Larry Jaques]

How about renting a better radar-type stud finder at the local equipment rental place?

[Greg Guarino]

It was apparently called "rock lath" or "button board". Here's a photo:

asterLath.jpg

[Larry Jaques]

Whoa! Dat ain't lath like I know it. They're long, thin strips. Interesting. 18x36" strips? It's downright weird.

[Leon]

As dadiOH mentioned, I have been there, although I used crown molding to hide an exterior wall alarm contact wire.

[Greg Guarino]

I found this:

"Gypsum or rock lath is a pre-manufactured plaster board, generally 16 inches by 48 inches in size, and 3/8 inch thick. Rock lath became popular in the 1930s as a less expensive alternative to wood lath. It is nailed directly to the wall studs and receives two coats of plaster over it. The rock lath is called the first coat and replaces the wood lath and the brown coat of the previous wet plaster system. The second coat is a cement plaster about 1/4 inch to 3/8 inch thick. The finish coat is then applied, which is comprised of hard finish plaster, and is approximately 1/8 inch thick."

Here's a photo of what this kind of wall looks like from the inside:

In my house the first coat of plaster is darker, more grey, than it looks in that picture. But the "fingers" of plaster protruding through are very much like what is shown.

I can tell you from experience that that first coat of "cement plaster" is some pretty rough stuff. I used a regular sheetrock Roto- Zip bit to cut out around an electrical box (why, you ask?). It worked well for the first two inches then stopped dead, like I'd hit an object behind the wall. I pulled the bit out of the wall and inspected it. A 1/4" or so of the bit had been worn down to a 1/16" thickness, exactly where it had been in contact with the grey "cement plaster".

The positives and negatives are pretty much like what you can read online. The walls feel nice and solid, much moreso than sheetrock. But yes, cracks can sometimes develop. I haven't had too much problem with that, but here and there I've had to make a repair.

So here's the "why" about cutting around the electrical box. I had a location with two 3-way switches, one above the other. They were of the old "despard" type, which uses a plaster ring that is unsuitable for any current switch. So I had to cut out a piece of wall large enough to remove the whole double-gang plate. But the fun was only beginning. It turned out that the existing box had screw thread locations that are also no longer standard (they were inset from the corners of the box about an inch). And get this, the box was NOT located against a stud. It had an arm that went off to one side several inches which was then affixed to the nearest stud. So replacing the whole box would have required much more damage and much more repair. If the builders weren't already dead I might have had to kill them.

I ended up tapping threads into the corners of the *rear* panel of the box and using long screws to hold the new plaster ring on. Followed by an education in how to repair a hole in a plaster wall. Another "2 hour job" that took a weekend.

[RP]

Locate the nail holes in the baseboard and you will know where the studs are.

RP