I've purchased an older home from an era when they used rock lath and plaster for the walls. I had never heard of this kind of construction, though I've done plenty of electrical wiring in older homes with regular lath and plaster. My question regards putting up shelving and coat hooks in my children's closets so they can reach their things. What is the best way to anchor to this material? I've tried locating the studs with the most sensitive stud-finder I could buy at our local hardware store but had no luck. I know about toggle bolts, but is this my only option? And how thick, generally, did they make these walls with the rock lath and the plaster together?
You can find studs in other ways, and then you can measure 16" centers.
- Look for nails in baseboard trim.
- Remove the covers of electrical outlets and determine which side contacts the stud.
- Look at exterior siding nail patterns.
- Tap with a mallet and listen for the more solid-sounding spot.
Drill a series of 1/16" holes at one inch intervals in a hidden area, such as behind a vent louver.
Measure 16" centers from the corner of a room that's at the outside corner of the building. (This may not hit center, but should get you close. You have a 50% chance of getting the layout from the correct end of the building.)
Ideally you'll mount to studs. I wouldn't hesitate to use togglers or expanding anchors where needed, though. That wall system was tough, and it isn't as fragile as wood lath in terms of disintegration.
My first home had it (or an evolution of it), and I liked it for its strength and durability. It would probably hold twice what modern drywall does. My walls were typically 3/4" to 13/16" thick (3/8" gypsum panel with 3/8" plaster).
Use a neodymium magnet to find studs, they're available online (e.g., Amazon). Some can hold up over 100lbs. They will find your studs. I would not use regular anchors, even though there is sheetrock behind your plaster (that's what sheetrock was invented for: replacing lathe, not plaster. Plaster gave way to a thin coat of joint compound and finally nothing but tape). European countries still plaster drywall (blueboard) as the standard.
You may find the magnets themselves can hold up what you want. Great for hanging pictures as well.