A large portion of homes in Greenwich, Darien, New Canaan, Westport, and Wilton were built before 1960. That means plaster and lath walls, not drywall. And plaster walls are where TV mounting goes wrong most often in Fairfield County, not because plaster cannot hold a TV, but because the approach used on drywall does not translate to plaster without modification.
This guide covers what plaster walls are, why standard stud finders fail on them, the three methods that reliably work for TV mounting in older Connecticut homes, and what you should never do on a plaster wall.
What Plaster and Lath Walls Actually Are
Plaster walls in pre-1960 Connecticut homes are built in three layers. First, wood lath strips are nailed horizontally across the studs with small gaps between each strip. Then three coats of plaster are applied: the scratch coat, the brown coat, and the finish coat. The wet plaster squeezes into the gaps between the lath strips and hardens, creating mechanical keys that hold the plaster in place. The result is a wall that is denser, harder, and more durable than drywall, but also more complex to work with.
The total thickness of a plaster wall from the stud face to the finished surface is typically 7/8 inch to 1 inch, compared to 1/2 inch for standard drywall. The multiple layers of different densities are what cause problems with standard stud finders.
Why Standard Stud Finders Fail on Plaster Walls
Standard stud finders work by detecting density changes in wall material. On drywall, the logic is simple: where the wall is denser, there is a stud behind it. On plaster walls, the density map is entirely different. The lath strips themselves create density variations. The mechanical keys of hardened plaster create density variations. The three layers of plaster create density variations. A standard stud finder scanning a plaster wall produces multiple false readings, often indicating studs every 4 to 6 inches when actual stud spacing is typically 16 inches.
Homeowners who rely on a stud finder on a plaster wall often end up drilling into lath, into plaster key, or into nothing at all. The result is either a hole that does not penetrate to a stud, or a damaged section of plaster that has been pulled away from the lath.
Do not use a standard stud finder as your only method for locating studs in a plaster wall. The multiple layers of plaster and wood lath create false readings that will send you drilling in the wrong location. Use the multi-step process described below.
How to Actually Find Studs in Plaster Walls
The reliable method uses three steps together, not any one of them alone:
Step 1: Measure from a known reference. Studs in pre-1960 construction are typically spaced 16 inches on center. Locate the corner of the room and measure out in 16-inch increments. This gives you probable stud locations. They are not guaranteed, but they are a starting point that drywall stud finders cannot replicate.
Step 2: Use a magnetic stud finder or neodymium magnet. The nails or screws attaching the lath to the studs are detectable with a strong magnet. Sweep the magnet slowly across the wall at the height where you measured. A pull toward the wall indicates a nail or screw, and therefore a stud location. This is slower than a digital stud finder but significantly more reliable on plaster.
Step 3: Probe drill to confirm. Before committing to the full mount hole, drill a small 1/8-inch pilot hole at the suspected stud location. If you feel resistance and the bit slows down after passing through the plaster, you have hit a stud. If the bit passes through easily with no resistance, you are in a gap between studs or in the lath.
This three-step process is what we use on every plaster wall TV mounting job in Fairfield County. It takes longer than a standard drywall install, but it produces an anchor that is as secure as any drywall installation.
Three Methods That Work for TV Mounting on Plaster
Lag Bolts Into Studs Through Plaster
This is the most secure and most direct method. Once you have located the studs using the three-step process above, drill through the plaster surface with a masonry or combination bit, then drive lag bolts rated for 250 lbs or more into the stud. The lag bolt passes through the plaster and into the wood stud behind it. The holding strength is equivalent to a standard drywall stud mount. This is the preferred method when stud spacing aligns with your TV's VESA hole pattern.
Most SecurePlywood Backing Plate
When stud spacing does not align with the TV's VESA hole pattern, the plywood backing plate solves the problem. A piece of 3/4-inch plywood, typically 16 inches wide, is secured to two studs with lag bolts. The plywood spans the gap between the studs and creates a solid mounting surface at any position across its width. The TV mount is then attached to the plywood, giving you full flexibility to position the TV exactly where you want it regardless of stud spacing. This method also distributes the load across two studs, which is ideal for heavier full-motion mounts.
Recommended for VESA MismatchNon-Pointed Molly Bolts for Plaster
Standard molly bolts have a pointed tip designed for drywall. The pointed tip cracks plaster rather than drilling cleanly through it. Non-pointed molly bolts designed for plaster require a pre-drilled hole, which allows them to be inserted without cracking the plaster surface. These can be used as supplemental anchors for lighter TVs on walls where stud access is very limited. For any TV above 40 lbs or any full-motion mount, molly bolts alone are not sufficient. They work as part of a combined anchor strategy, not as the primary hold on a heavy TV.
For Light Loads or Supplement Only
What Does Not Work on Plaster Walls
Understanding what fails on plaster is just as important as knowing what works.
Standard Plastic Anchors
The plastic expansion anchors sold in hardware stores are designed for drywall. In plaster, the anchor hits lath or plaster key and either does not expand correctly or pulls through the brittle plaster surface under load. Never use these for a TV mount.
Pointed Molly Bolts
The pointed tip is meant to push through drywall by tapping with a hammer. In plaster, tapping causes the plaster to crack around the anchor point, weakening the hold before anything is even attached. Use non-pointed molly bolts with a pre-drilled hole instead.
Toggle Bolts in Deteriorated Plaster
Toggle bolts can work in sound plaster, but many older Fairfield County homes have plaster that is separating from the lath or has moisture damage. In deteriorated plaster, the toggle pulls through when the TV mount is loaded.
Stud Finder as the Only Locating Method
The single most common mistake. Multiple layers of lath and plaster create false density readings that send the installer to the wrong location. Stud finder results on plaster should always be verified with magnetic detection and a probe drill before committing.
TV Mounting on Plaster Walls in Fairfield County
We handle plaster and lath walls in Greenwich, Darien, New Canaan, Westport, and Wilton. Flat-rate pricing from $199.
Book Online NowPlaster Walls and Samsung Frame TVs
If you have both a Samsung Frame TV and plaster walls, the install requires careful coordination. The Frame mount needs to align with the inner VESA holes, which sit at a specific position on the back of the TV. The stud spacing in your wall may or may not align with those holes. In Fairfield County homes where this mismatch occurs, the plywood backing plate method is the solution. The plywood is anchored to two studs, and the Frame mount is positioned on the plywood at the correct location for the inner VESA holes.
See our full guide to Samsung Frame TV mounting in Connecticut for the complete rundown on Frame-specific requirements.
Full-Motion Mounts on Plaster Walls
Full-motion and articulating TV mounts require more attention on plaster walls than standard fixed or tilt mounts. When a full-motion arm extends 12 to 18 inches from the wall with a heavy TV attached, the lever force on the wall mount bracket is significantly higher than the static weight of the TV. On drywall, we use lag bolts into two studs minimum for full-motion mounts. On plaster, we use the same approach but the stud verification process is more thorough, and in cases where stud spacing limits the anchor pattern, the plywood backing plate method is used to ensure the bracket attaches across a full 16-inch stud span.
The Short Version for Fairfield County Homeowners
Plaster walls hold TVs just as well as drywall when the mounting is done correctly. The studs behind plaster are identical in strength to the studs behind drywall. The difference is entirely in the process of finding those studs and installing the anchor through the plaster surface without damaging it.
If your home was built before 1960 and is in Greenwich, Darien, New Canaan, Westport, Wilton, or Weston, you almost certainly have plaster walls. Do not attempt a TV mount with a standard stud finder as your only location tool. And do not use standard plastic wall anchors under any circumstances.
Alliance Handyman Pros serves all of Fairfield County with flat-rate TV mounting in Connecticut starting at $199. We work on plaster and lath walls regularly across the service area. Same-day availability in Greenwich, Darien, Westport, Stamford, and New Canaan. Call (475) 500-7126 or book online.