TV Mounting on Plaster Walls in an Old House — Lath and Studs
A 1920s or 1950s house with plaster walls, a stud finder that beeps everywhere, and a fear of cracking the wall before the TV is even up.
JMB Builders does TV mounting on plaster walls in old houses across the Twin Cities metro and St. Cloud. We find the studs behind the lath by the nail lines and test holes, drill clean pilot holes so the plaster does not crack, and lag the mount into framing. When the studs miss the spot, a painted backer board spans them. Priced per TV, quoted from a wall photo within one business day.
- Priced per TV, plaster and lath walls
- Studs found through lath, not guessed
- Pilot holes drilled so plaster stays put
- Backer board when studs miss the spot
- Licensed MN contractor BC809005
Plaster walls are hard, thick and brittle, and they sit on wood lath nailed across the studs. An electronic stud finder reads the lath and the plaster keys as solid wood almost everywhere, so it is close to useless. Older homes in St. Paul, Minneapolis, Anoka and St. Cloud also have studs that are not on a modern layout, full-dimension lumber, and sometimes a balloon-framed wall with open bays top to bottom.
We find the studs another way: a strong magnet run along the wall finds the rows of lath nails, which line up over each stud, and a small test hole behind where the mount will cover confirms it. The hole is drilled with a sharp bit, not the hammer setting, starting small and stepping up, with tape on the plaster so the edge does not chip. The lags go into the stud, not just the lath.
When the studs are not where the TV needs to be — off-center on a chimney wall, or one stud for a full-motion arm — a backer board goes up first. It is a flat hardwood or plywood panel, painted to match or to look deliberate, lagged across two or three studs, and the mount bolts to it anywhere you want.
What you supply
- The TV and the mount, or the TV model so we bring a mount that fits
- A straight-on photo of the wall with the outlet, trim and furniture in it
- Any cracks or loose plaster you know about on that wall
- Paint color if you want the backer board or patches painted
What JMB supplies
- Stud location by lath nail lines and test holes behind where the mount covers
- Pilot holes drilled step by step with the plaster taped, no hammer drill
- Lags long enough to pass the plaster and lath and bite the stud
- A backer board lagged across the studs when the bracket cannot land on one
- Loose plaster around the mount screwed back with plaster washers before mounting
- The TV hung, leveled and locked, and dust vacuumed as we drill
- Painting of the backer board or patches, quoted as its own line
How it is priced: per unit
Quoted in writing from your photos within one business day. What moves the number:
- TV size and mount type: a full-motion arm needs more fastening than a fixed mount
- Whether the studs fall under the bracket or a backer board is needed
- Condition of the plaster: sound, cracked, or loose from the lath
- Wires in the wall: open balloon-frame bays vs. walls with fire blocks or old wiring
- Mount supplied by you or by us
- Painting of a backer board or patch
Send a straight-on photo of the wall and a close-up of any cracks near where the TV goes. That shows us whether a backer board is likely.
How long it takes
One TV on sound plaster over studs: one to two hours. With a backer board: half a day, plus paint if we are painting it.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Lagged into studs through plaster
The standard job when the studs line up with the bracket: studs found through the lath, pilot holes drilled step by step, lags into framing. A fixed or tilt mount on sound plaster is the simplest version.
Backer board on plaster
A painted hardwood or plywood panel lagged across the studs, with the mount bolted to it where the TV needs to be. Used when the studs are off-center, on chimney walls and for full-motion arms.
Wires in a plaster wall
Low-voltage cables dropped inside the wall to the console. Balloon-framed bays are often open floor to ceiling; other walls have blocking. Old wiring found in the wall stops the fishing until a licensed electrician looks at it.
TV Mounting on Plaster Walls in an Old House — Lath and Studs: questions, answered
How do you find studs in plaster walls to mount a TV?
Not with a regular stud finder; it reads the lath everywhere. A strong magnet slid along the wall sticks to the lath nails, and the nails line up in a vertical row over each stud. A small test hole or a thin finish nail in a spot the mount will cover confirms it. Measuring from a door or window casing, which is nailed to a stud, helps too.
Will drilling into plaster crack the wall?
Not if it is done right. Use a sharp bit with the hammer setting off, tape the spot, start with a small pilot and step up, and let the bit cut instead of pushing hard. Plaster cracks from vibration and pressure. Plaster that is already loose from the lath gets screwed back with plaster washers before anything is hung on it.
Can a plaster wall hold a heavy TV?
Yes, when the mount is lagged into the studs behind it. The plaster itself does not hold the weight; the framing does. Old houses usually have solid, full-size studs. What a plaster wall cannot do is hold a TV on drywall anchors or toggles in plaster and lath alone.
What if the studs are not where I want the TV?
A backer board. A flat panel of hardwood or plywood is lagged across two or three studs, painted to match the wall or stained as a feature, and the mount bolts to it anywhere on the board. It spreads the load, lets the TV be centered on the wall or chimney, and leaves only a few lag holes in the plaster if it ever comes down.
Can you hide the TV wires inside a plaster wall?
Often, yes. Many older homes are balloon framed, with stud bays open from the basement or attic, which makes fishing cable easier. Other walls have blocking that has to be drilled through. If the wall has old knob-and-tube or cloth wiring in it, we stop and a licensed electrician looks at it before we fish anything past it.
Do you mount TVs in old houses in St. Cloud?
Yes. We work across the Twin Cities metro and north to St. Cloud, and older homes there often have plaster walls. Send a photo of the wall and the TV model and the quote comes back within one business day.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and for the builders and dealers we sub for. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
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Read morePage reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All tv mounting pages
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