Hanging a Heavy Coat Rack on a Plaster Wall
I've just moved into a 100-year-old house with plaster walls. My gentleman friend is coming over to help me hang things and he says hanging on drywall is the same as plaster. What do I need to know about hanging fairly heavy things on a plaster wall that's different from hanging them on drywall? I'm thinking specifically of a wooden coat-hook cabinet-like item that has six hooks for coats, and cubbyholes above for caps, gloves, etc. I estimate the item itself weighs about 25-30 pounds. Add the weight of all those winter coats and I'm concerned we'll be pulling plaster off the walls!
Whether the wall is old plaster or new gypsum drywall, it's always better to attach something heavy directly to studs inside the wall. Framing is the most reliable point of attachment.
In a recently built house, it should be simple to find wall framing because studs are laid out on 16-inch centers. Find one stud and you know exactly where its mates are.
Life isn't so predictable in an old house. Studs are often spaced erratically. Still, if your cabinet is at least a couple of feet wide you should be able to find one and possibly two studs you can use.
To be sure, you may have to drill a series of small, exploratory holes across the wall where you intend to hang the cabinet. As long as the cabinet has a back, it hardly matters. The holes are covered when the cabinet is installed. And if you remove the cabinet later, you can patch small holes.
Once you've found the framing, you can attach the cabinet to the wall with screws. The fasteners should penetrate the framing by at least 2 inches. Make sure, however, the cabinet comes with blocking or a hanging rail that can carry the load. A flimsy hardboard back isn't enough.
When it's not possible to find wall framing to support heavy loads, hollow-wall anchors are an alternative. There are several types to choose from, and some can hold a surprising amount of weight.
Plastic anchors and auger anchors work just fine for light loads in gypsum drywall, but I'd be reluctant to use them in a plaster wall that's a century old. In time, plaster can separate from the underlying wood lath as the keys of plaster poking through gaps in the lath break off. If the anchor grabs just this outer layer of old plaster, the connection won't be very strong. You might indeed pull plaster right off the wall.
Other types of wall anchors are designed to go through the entire thickness of wall and expand on the back side so they can't be withdrawn. That's how molly bolts and toggle bolts work. Of the two, toggle bolts are stronger. Some are rated to hold more than 100 lbs.
If you could get a toggle all the way through the plaster and the lath behind it, you should have a robust connection. That said, with something as heavy as what you're describing, a direct connection to wall framing is a better choice. If nothing else, you wouldn't worry about it.
An accomplished woodworker and carpenter, Scott Gibson is the former editor of Fine Woodworking magazine, and a former editor at Today's Homeowner and Fine Homebuilding magazines. He also is former managing editor of the Kennebec Journal, a daily newspaper in Maine.