A job in a 1920s house made me stop trusting my stud finder

I was working on a remodel in this old place in Pasadena, trying to hang a heavy mirror. My digital stud finder kept going off all over the wall, showing studs every 8 inches. I mean, I was about to start drilling when the homeowner, this older guy who grew up there, said they used old growth lumber and plaster lathe. He told me to just knock on the wall. I did, and the sound was totally solid and even across the whole section. I ended up using a tiny drill bit to probe and found the real studs were 24 inches on center, not 16. The finder was picking up all the wood lathe strips. Now I always do the knock test and a manual check in older homes before I trust the tool. Anyone else run into this with plaster walls?

3 comments

3 Comments

emma_lee225d ago

Check the plaster for metal mesh too. My buddy's finder went nuts from that old wire lath, gave him a totally false reading. Old houses just have their own rules sometimes.

kelly_rivera5d ago

Heard a contractor on a podcast say the same thing. Said you can sometimes tap the wall and listen for a hollow spot instead. Those old houses are full of surprises.

barbaradavis5d ago

Tap test is the only thing that works.