On Sat, 9 Feb 2013 06:57:10 -0800 (PST), Greg Guarino
wrote:

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.

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.
--Paul Newman