This is not really a woodworking question, but I figure someone here
can answer it.
My Dad is 92 and needs to grab onto things to climb the stairs. But
for a short section of the stairway in their house, there's no
sensible thing to grab.
Their house is plaster on lath if memory serves. Wood strips, I think,
not wire. [This is an ancient memory. My parents had a larger closet
made when I was a very young boy and I was allowed to bash away at the
plaster for a little while. I remember being disappointed when I came
back from school and found that the rest of the demolition had already
been completed. ]
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 it comes
down to it, I suppose I could remove the base molding and drill holes
at the bottom of the wall, but the molding is finished oak, and a
little complicated, and would be very hard to replace if an oaf like
me were to damage it.
Suggestions? I imagine I'd use oak railing parts from the Borg, by the
Tough to do with an inexpensive stud finder or other inexpensive
electronics, and even Leon's favorite earth magnet trick won't work with
some of the lath behind plaster walls.
The only way we've been successful is to start on a corner, measure the
usual 16 OC, then pray/sound with a 1/16" drill bit ... small enough to
cover up with a close match of putty.
IME, and no matter how much you spend on a Borg stud finder for a
plaster wall, you end up doing that anyway.
OK. Was 16" "standard" before there was sheetrock? (and yes, I'm aware
that even if it was, I might not find that spacing) The house was
built in 1939, I think. My house has plaster walls as well, but over
"plasterboard"; like sheetrock, but with a grid of holes for the
plaster to grab onto. Their house is just plaster on lath.
Depends ... 16" OC, for a 2x4 studs in platform framed is "standard" in
most codes dating far back; 24"OC is "standard" for 2x6 studs.
If the house is two story, and has balloon framing, which is not
uncommon in houses of that vintage, you may find it closer to the latter
I can tell you one thing ... you will not be happy with ANY stud finder
you can buy at a BORG. End of Story
If you have to get destructive to anchor that thing for your Dad's
safety, which is of paramount importance, Leon's suggestion about using
a trim board behind the hand rail is excellent advice.
I have a quick story.
I helped a buddy rehab the old family homestead place to live in. It was
documented in the family to 180 years old in 1985. That makes it almost 210
years old, now.
Anyway, built with lumber cut off of the property. Cedar studs and poplar
joists and rafters. ALL at EXACTLY 16 inches on center. Amazing.
Perimeter beam, balloon frame, studs 19 feet long.
On the other hand, I have worked on many much younger houses with totally
random spacing, also.
On Sat, 9 Feb 2013 06:57:10 -0800 (PST), Greg Guarino
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.
Newman's First Law:
It is useless to put on your brakes when you're upside down.
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
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.
Know anyone with a ground penetrating radar unit? Call the Feds and tell
them you "think" you might have a lead on Jimmy Hoffa.<g>
Seriously, two things to consider:
1) Use heavy duty Molly anchors. Drill a pilot for them first and if if
you hit a stud, shift gears and start measuring for the rest of them.
2) stay with the Molly's if you don't hit a stud first thing, if you
eventually hit one, just switch gears for THAT mount.
3) Go down to the Borg and buy a Zircon Stud Finder. Not the most
expensive one, but not the cheapest either. I had their original one, a
black thing with LED's that looked like a TV remote. Didn't work all
that well. Took another bite of the apple several years later and got
one that cost me about $20 - $25 and love it. WTH, if it doesn't work
out, you can always return it for a refund, right?
Don't suppose you know how regular the wall stud spacings are, even, do
you? Sometimes in those old houses they're as regular as a Swiss watch;
sometimes not so much...if they are regular and there's a good corner at
one end from which to measure, you've got a reasonable chance.
I've not used one so can't say firsthand but reviews of some of the
better (as in higher-$$) Zircon and Bosch sounders worked reasonably
well w/ plaster walls in a Fine Homebuilding review -- not sure otomh
which issue; think it was about first of maybe 2011 based on a quick
view of comments...
There are those who say the rare-earth magnet "StudTHUD" is supposed to
be the cat's meow...
I've not further info other than that on it, though...
One thing is that if the plaster is in good shape on a wood lath paster
wall you can use a moly bolt and by getting across and behind the lath
it'll be very strong even if you do miss a stud...
I'd like it to be VERY strong. He doesn't just steady himself on the
railing, he practically seems to pull himself up the stairs. I'll
feel better, if nothing else, if I get the brackets into the studs.
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