The best stud finders for plaster walls are multi-sensor electronic units with deep-scan modes, because plaster is thick enough and lath is dense enough to defeat a standard drywall finder. A magnetic tool is a confirmation device, not a primary locator. I spent weeks comparing ten of them on old walls, and the gap between the winners and the rest is almost entirely about depth and calibration.
Most consumer stud finders are rated to about 3/4 inch. Plaster over lath routinely measures well past that, which is why so many owners report a scanner that beeps confidently on the plaster surface and points at nothing structural. On my test walls the failure is predictable: the tool locks onto the lath strips and the fastener nails, not the stud behind them.
That is the entire reason this roundup exists. I compared these ten scanners on lath and plaster, drywall, and heavily patched walls, and I scored each one on depth rating, calibration behaviour, whether it can give you a stud center rather than a fastener point, and whether it warns you about live wiring. For the broader picture of how these tools work on standard modern walls, my general stud finder accuracy roundup covers the drywall case in depth.
One note before we start: two of the ten tools below are explicitly excluded by their own manufacturers for lath and plaster walls. I kept them in the list because knowing which tools will not work is as useful as knowing which will.
Our Top 3 Tested Picks for Plaster and Lath Walls in 2026
Franklin ProSensor 710
- 13-sensor array
- No calibration needed
- LED bar shows full stud width
- Deep scan to 1.6 in
StudPoP Moving Magnet
- 1 inch moving magnet
- No batteries
- Clicks on a fastener
- Reads through thick plaster
Quick Picks and How the Ten Scanners Compare
Here is the short version if you are standing in front of an old wall right now.
Best overall: Franklin Sensors ProSensor 710 – a 13-sensor array with deep scan always on to 1.6 inch, so there is no mode to forget to switch to.
Best for thick plaster: Franklin Sensors ProSensor M210 – the deepest rated scan in this group at 1.7 inch, with live wire detection for drilling safety.
Best for fast confirmation: StudPoP Original Moving Magnet – no batteries, no calibration, and it finds the fastener row that means a stud is behind it.
Best value in the Franklin line: ProSensor M150 – 9 sensors and live wire warning at just over 5 ounces, with a 1.5 inch deep scan.
Best for lath and slat walls: Jurgen K 5-in-1 Wall Scanner – the only unit here whose manufacturer explicitly names lath and slat surfaces together as supported.
Best center readout: Mecurate 5-in-1 – the clearest LCD for reading a stud center instead of guessing between two edge beeps.
Best for marking several studs: Calculated Industries StudMark – rare earth magnets plus two removable markers, though its maker advises against plaster.
Best rechargeable: FNIRSI WD-01 – a positioning hole that marks the exact drill point, on a lithium polymer battery.
| Product | Specs | Action |
|---|---|---|
| Franklin ProSensor 710 |
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| Franklin ProSensor M210 |
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 Franklin ProSensor M150 |
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 Jurgen K 5-in-1 Wall Scanner |
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 Mecurate 5-in-1 Wall Scanner |
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 Walabot DIY 2 |
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| StudPoP Moving Magnet |
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 Calculated Industries StudMark |
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 FNIRSI WD-01 |
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 Kreg Magnetic with Laser-Mark |
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Why Plaster Walls Break Most Stud Finders
Three things happen between a drywall finder and a plaster wall, and each one degrades the reading.
Wood lath versus metal lath decides which tool you need
Wood lath is a grid of 1.25 inch wide strips nailed across the framing, with gaps between them. An electronic sensor reads the density change at each strip and each nail row, so it produces a picket fence of false positives that looks exactly like a stud. A magnet ignores the wood entirely and latches onto the steel nails, which run in a line only where lath meets a stud.
Metal lath is a different problem entirely. One poster on the Fine Homebuilding forum describes reading it as mission impossible, and the reason is physical: expanded metal mesh is a continuous conductive sheet, so a magnet has nothing discrete to grab and a density sensor has one uniform signal to measure. If your wall has metal lath, only a radar-style scanner has a chance, and even then the manufacturer warnings matter.
Plaster thickness versus rated detection depth
Typical plaster is about 1/2 inch thick over lath, and it is often built up in two coats. Add the lath depth and you are looking at a combined assembly that exceeds the rated detection depth of most consumer finders. Before buying anything, measure your own wall: put a flat blade or a thin screwdriver through a spot of missing plaster, or measure at an existing hole, and compare that number to the scanner’s rated depth. A tool rated 0.75 inch is useless on a 1.5 inch assembly.
Stud spacing in pre-1960 homes is not 16 inches
Framing in older homes frequently runs at 12 to 20 inches on center, and it is not always consistent within the same room. Homeowners who measure 16 inches from a corner, mark a line, and drill confidently are working from a modern assumption that fails in exactly the houses most likely to have plaster. Several regulars on r/centuryhomes make the same point: find the first stud honestly, then measure the actual spacing before you trust any marks after it.
1. Franklin Sensors ProSensor 710 – The Most Accurate Multi-Sensor Array on Plaster
Franklin Sensors ProSensor 710 13-Sensor Stud Finder Wall Scanner
13 sensors
No calibration
1.6 in deep scan
Lateral accuracy within 0.25 in
Pros
- 13-sensor array is more accurate than 1-2 sensor finders
- No calibration so you can start scanning anywhere
- LED bar shows full stud width and double studs
- Deep scan always on with no mode to forget
- Lateral accuracy within 0.25 inch
Cons
- No live wire detection unlike the M210
- Needs two AA batteries that are not included
- Full-size body is bulky for pocket carry
This is the tool I reach for first on an unknown wall, and the reason is not the sensor count alone. It has no calibration step, so you can put it on the wall over a suspect area and start moving. On plaster that removes the single biggest source of bad readings, which is a scanner calibrated against the wrong part of the wall.
The LED bar is the other thing that matters here. Instead of beeping at one edge and leaving you to infer the center, it lights up the full width of the stud and turns the middle indicator green when you are centered. On a lath wall, where false edges are everywhere, seeing a continuous block of light is much harder to fake than a single beep.
Detection depth and what the 1.6 inch rating covers
Most entry-level finders use one or two sensors, so they average a reading over a wide area, and plaster and lath create abrupt density changes every few inches. Rated to 1.6 inches, deep scan is permanently active rather than a mode you toggle, which matters because a user who forgets to switch modes simply gets nothing and assumes there is no wall structure. The spec sheet lists lateral accuracy within 0.25 inch, and 79 percent of its ratings are five star.
For whom it works and where it falls short
This suits anyone mounting a shelf, a French cleat or a framed mirror in a pre-1960 house who needs a stud center rather than a fastener guess. The gap is safety: there is no live wire detection, so if your home predates modern cable you should pair it with a magnet pass and a small pilot hole before committing a long lag screw.
2. Franklin Sensors ProSensor M210 – Deeper Scan and Live Wire Warning
Franklin Sensors ProSensor M210 13-Sensor Stud Finder, Live Wire Detection
13 sensors
1.7 in deep scan
Live wire detection
Built-in bubble level
Pros
- Deepest rated scan in this roundup at 1.7 inch
- Live wire detection adds drilling safety
- Bubble level helps mark plumb lines
- No calibration required
Cons
- Two AA batteries required and not included
- Compact body is denser and heavier than the M150
- No carrying case included
The M210 is the 710 with the two features you want when the wall is genuinely old. Its 1.7 inch rated depth is the deepest in this group, and the live wire detection is the part that changes how you work rather than just what you find.
On a wall that may contain knob-and-tube or original cloth-sheathed cable, a wire warning changes your sequence. You can scan the whole area first, note every reading, and pick a spot with no wire indication before you ever touch a drill. Several posters on r/handyman describe drilling first and verifying later as the expensive way to learn this lesson.
Best for depth, wires and precision marks
The built-in bubble level earns its place on a plaster wall, because a stud line that drifts half a degree over eight feet puts your screw outside the wood. The pencil caddy holds a marking pencil at the correct height so your hand stays in the same position during the scan, which improves consistency on lath where readings are noisy. Choose it when the wall is thicker than an inch, when there is any chance of legacy wiring, and when a missed stud means damage.
Where the extra money goes
The step up from the 710 buys depth and a wire warning, two features you may already get from a separate magnet and a careful pilot hole. On a wall where drilling into wiring is a real possibility, the warning is worth having.
3. Franklin Sensors ProSensor M150 – Nine Sensors in a Pocketable Body
Franklin Sensors ProSensor M150/X990 9-Sensor Stud Finder, AC Wire Warning
9 sensors
1.5 in deep scan
Live wire warning
5.12 oz weight
Pros
- Lightest Franklin multi-sensor unit at 5.12 ounces
- Genuinely pocketable for a job site
- No calibration required
- Full stud width display with green center LED
- Live wire warning for safer drilling
Cons
- 1.5 inch depth is shallower than the M210
- Needs two AAA batteries not included
- No rechargeable battery support
- One-star share of 6 percent is slightly higher than the 13-sensor models
If the M210 is too much tool for a single afternoon of picture hanging, the M150 is the sensible step down. It drops two sensors and a tenth of an inch of depth and saves you the weight of a full-size body, landing at just over 5 ounces.
That 1.5 inch rating still clears the common plaster-over-lath assembly, which is the whole reason it earns a place here. Its live wire warning gives it the same safety footing as the M210 despite being the smaller and cheaper unit.
A portable pick for renters and first apartments
Measure your plaster depth before you commit. If the plaster and lath together come to about an inch and a half, the M150 reads comfortably; if a previous owner added a coat of plaster, or your lath is wider than the usual 1.25 inch strips, you are at the limit and the M210 is the safer choice. Its 4.4 average across more than 4,300 reviews reflects a well-liked unit with a small, predictable set of complaints rather than a design problem.
4. Jurgen K 5-in-1 Wall Scanner – The Only Unit Explicitly Listed for Lath
Stud Finder Wall Scanner, 5 in 1 Multifunction Stud Locator with Smart Sensor, HD LCD Display and Audio Alarm for The Center & Edge of Metal, Studs, AC Wire, and Pipe Detection (Tropical Orange)
Stud scan to 1.5 in
Metal scan 60 mm
AC scan 51 mm
Backlit LCD
Pros
- Manufacturer names lath and slat surfaces as supported
- Backlit HD LCD with low-power indicator
- Continuous beep so you are not holding a button on a ladder
- Included 9V battery
- Auto calibration by placing flat on the wall
Cons
- AC and metal modes frequently reported as unreliable
- Very sensitive to electromagnetic fields from live outlets
- Accuracy drops if you move the tool too quickly
- Some users report inconsistent results on repeat scans
This scanner is the odd one out in the category, because its manufacturer actually names lath and slat walls as a supported surface, which most competitors avoid. Its three stud depths of 1/2, 1 and 1.5 inch let you work from the surface inward, which is the right approach when you do not know the assembly thickness.
The continuous beep is a genuine ergonomic win over the press-and-hold designs. When you are on a ladder working above your head, holding a button down and watching an LED at the same time is not realistic, and this one keeps scanning and sounding while you move.
Where the accuracy holds and where it does not
Stud scan, deep scan, metal scan and AC scan are the useful modes. Metal mode covers 60 mm and AC mode 51 mm, both deeper than the stud modes. Reviewers are consistent about the split: stud and deep scan are praised as precise and good at locating centers, while the AC and metal modes draw the complaints, including a live-wire light that stays on across walls with no wiring in them.
It auto-calibrates by sitting flat on the wall with the scan button held, and the reviews make it clear that results improve sharply when you calibrate on a known empty area and move slowly. Fast scanning across a lath wall produces readings that do not repeat, which is exactly the failure mode that makes people distrust the whole category.
Where this scanner earns a place
Pick it if your wall is confirmed wood lath and you want a display you can read at arm’s length. Avoid it if your home has any suspicion of old cloth-sheathed wiring, because the electromagnetic sensitivity here means a live outlet in the room can light the AC indicator across a large area of wall.
5. Mecurate 5-in-1 Wall Scanner – The Clearest Center Readout
Mecurate 5-in-1 Stud Finder Wall Scanner for Studs, Metal & Live AC Wires
Deep scan 1.5 in
Metal scan 2.375 in
AC scan 2 in
Includes battery and pouch
Pros
- LCD graphics show stud center rather than just edges
- Audio alerts let you scan without watching the screen
- Battery and carrying pouch included out of the box
- Simple one-handed calibration
- Deep 1.5 in mode handles most plaster over lath
Cons
- Manufacturer states best performance on single-layer drywall
- Needs recalibration after each stud is marked
- 22 percent of reviews are 1-3 star on repeatability
- Not recommended for concrete brick or tile
The Mecurate’s advantage is that it draws the stud on the screen instead of describing it. A row of LEDs shows you the width of what it found and where the center falls, which removes the guesswork of counting inches from a beep. On a lath wall full of false edges, that visual is worth more than another sensor.
It also ships with a 9V battery and a carrying pouch, so there is nothing to buy before you start. The deep mode reaches 1.5 inch, the metal mode 2.375 inch, and the AC mode 2 inch.
Reading the center instead of the edges
The manufacturer’s documentation states that performance is best on single-layer drywall and does not recommend the unit for concrete, brick or tile. Plaster is not excluded by name, but treat a reading here as a candidate location rather than a location, and verify it with a pilot hole.
Recalibration and repeatability
This is the unit with the widest dissatisfaction spread of the LCD scanners here. Roughly 22 percent of reviews are one to three stars, and the theme is repeatability: some owners scan the same wall twice and get different answers. Recalibrating after each marked stud is the fix, and the LCD makes that easy to do consistently.
Who should buy it, and who should not
It suits a beginner who needs visual feedback while learning what a stud reading looks like on an old wall. Skip it if you need a tool you can trust to repeat identically across a large room, or if your home has metal lath, which this class of density sensor cannot resolve.
6. Walabot DIY 2 – Impressive on Drywall, Excluded From Plaster
Walabot DIY 2 – Visual Stud Finder & Wall Scanner for Drywall. Detects Wood & Metal Studs, Plastic & Metal Pipes, Live & Non-Live Wires
Radar visual imaging
Detects to 4 in
Phone app via internal Wi-Fi
95 percent stated accuracy
Pros
- Visual image makes stud centers far more reliable than beeping
- Built-in Wi-Fi hotspot works with no network present
- Detects high-voltage wiring and some piping
- Rechargeable battery with cable included
- Works with iOS and Android
Cons
- Manufacturer explicitly says not to use on lath and plaster
- Must recalibrate on every visit to a wall
- App connection failures reported by many users
- Cannot distinguish a pipe from a wire
- Calibration sweeps can scuff paint
This is the only true radar unit in the group, and on drywall it is genuinely impressive. Instead of a beep it draws an image of the wall contents on your phone, showing stud centers, pipes and wire paths. Owners who were previously guessing at centers describe finding a stud in about half a minute.
And then there is the catch, which for this article is decisive. The manufacturer’s own support material says to use it only on drywall and plywood, and specifically not on lath and plaster, concrete, tile, brick, metal-backed walls or stucco. On a plaster wall you would be using it entirely outside its stated limits.
What the radar image actually is
It is a rendered interpretation from a single radar reading, not an x-ray. Horizontal or diagonal members can be drawn as vertical studs, and the tool cannot tell a pipe from a wire. You also sweep large circles over the scan area before every use, with no way to skip that on a wall you already calibrated, and that sweeping motion can rub paint off an old plaster surface.
A strong drywall tool and a poor plaster tool
It is a good drywall tool and a poor plaster tool. If your project is a modern renovation on new sheetrock, the visual center-finding is the most satisfying experience in this list. If you own a 1920s house, keep reading, because the manufacturer has already answered the compatibility question for you.
7. StudPoP Original Moving Magnet – The Fastest Way to Confirm a Stud Exists
Original StudPoP Moving Magnet Stud Finder, for Any Construction, 1″ Magnet
1 inch moving magnet
No batteries
Works on plaster and tile
Reacts only to fasteners
Pros
- Owners in very old plaster houses report success where electronics failed
- No batteries to buy charge or change
- Visual and audible pop removes the guesswork of a tug test
- Works through thick plaster tile and exterior walls
- Fits in a pocket at 1.12 ounces
Cons
- Some users report false positives from irregular lath fastener positions
- Finds fasteners only so it cannot show stud width or center
- A minority find the magnet too weak for thick plaster and lath
- Very small and easy to misplace
There is a 1 inch magnet inside this small plastic cylinder, and when it finds a metal fastener the internal mechanism lifts and clicks. That is a real improvement over a bare magnet, where you are guessing whether the tug you feel is a stud or a pipe. One owner in the reviews found the first nail in seconds after spending over an hour with an electronic finder.
Because it reacts only to fasteners, it is not fooled by plumbing or ductwork the way a magnet dragged around a basement would be. There are no batteries, so it cannot die mid-job or give a flat reading from a weak cell.
Why fasteners tell you where the stud is
Original lath was nailed to the framing, so the nails fall in a straight line only where a stud sits behind them. When the popper clicks repeatedly along a line rather than once in a scattered pattern, you have located framing.
Where plaster was later covered by drywall, extra fasteners from the drywall layer and the lath layer can coexist, which produces a dense field of false hits. The fix is to slow down and look for a line, not a point. Several owners on r/DIY describe exactly this method, using a magnet to find the nail row, then estimating the center from the spacing between nails.
For whom it works and where it falls short
It is the right first tool in an unfamiliar old house and the right second opinion for any electronic reading. It cannot tell you the stud width or center, so mounting a wide or heavy object on a single nail line needs the electronic tool or a pilot hole to confirm.
8. Calculated Industries StudMark – Mark Multiple Studs Hands-Free
Calculated Industries 7310 StudMark Magnetic Stud Finder with Markers
Rare earth magnets
Two removable markers
No batteries
2-year warranty
Pros
- Only magnetic finder here that ships with two removable stud markers
- Magnets hold the tool to the wall leaving both hands free
- No batteries so no failures on a job site
- Compact enough for a pocket or nail pouch
- Backed by a 2-year warranty
Cons
- Manufacturer states it is NOT recommended for plaster walls
- Finds fasteners only and not the stud width or center
- Only 2 markers included capping marked locations at 3
- Sparse customer image and long-form review coverage
The idea here is simple and I like it. The rare earth magnet holds the finder against the wall so both hands are free, and when you locate a fastener you twist one of the two included magnetic markers onto the wall as your mark. You end up with clean visible marks instead of a scatter of pencil lines, and you can mark up to three stud locations before running out of markers.
The Z-pattern scanning method it teaches is a good habit. You sweep a Z across the wall surface so the magnet engages from several angles, which is more reliable on uneven old plaster than a single straight pass.
The manufacturer statement you need to read
Calculated Industries explicitly states that because of thickness variations, the StudMark is not recommended for plaster walls. That is not a review complaint, it is the maker’s own guidance, and it is the single most important sentence to know about this product for anyone reading this roundup. On a plaster-and-lath wall, a magnet that will not stick to a nail tells you nothing, so I would not make it your primary plaster tool.
The right tool for picture hangers and carpenters
On drywall or plywood the hands-free grip and the two markers save real time, and the 2-year warranty covers manufacturing defects. For a plaster wall the manufacturer has already ruled it out, so choose between the StudPoP and an electronic multi-sensor unit instead.
9. FNIRSI WD-01 – Rechargeable With a Marking Hole Built In
FNIRSI WD-01 6 in 1 Rechargeable Stud Finder Wall Scanner, Positioning Hole
Positioning hole for marking
Depth scan 1.5 in
Ferrous metal to 4.7 in
Rechargeable
Pros
- Rechargeable battery removes battery replacement entirely
- Positioning hole marks the exact drilling location
- Manufacturer states it works on lath among other surfaces
- Auto calibration completes in about a second
- Deepest range in the group for ferrous metal at 4.7 inches
Cons
- One user reports edge and center finding unreliable on plaster and lath
- AC detection can report live wiring where none exists
- Center finding described as too sensitive and off by half an inch
- Some users report failure to detect metal pipe behind drywall
The positioning hole is the feature I would keep. Once the tool reports a finding, you slide it into position and put a pencil through the hole, and that mark is the drill point rather than a rough guess at a stud center. On a wall where your margin for error is a quarter inch, that is worth a lot.
Its six-in-one detection list is the deepest in the group for metal: exact scan to 0.75 inch, depth scan to 1.5 inch, non-ferrous metal to 3.9 inch and ferrous metal to 4.7 inch. One owner credits it with locating rebar during a pool demolition, which is well outside a stud finder’s normal job.
The lath claim and the plaster report
The manufacturer lists lath, wallpaper, wood flooring, acoustic ceiling and painted walls as supported. The most relevant customer review in the set is from a plaster and lath wall where the edge and center finding was unreliable, and the user fell back to locating nails and estimating the center by hand. Treat the center mode with suspicion on plaster and trust the point readings. Scanning a wall properly takes longer than most people expect, and a lithium polymer cell that recharges over USB removes the mid-job battery failure entirely, which is the one design change in this category in recent years that made a real difference for me.
For whom it works and where it falls short
Choose it if you want a single tool that covers drywall, plaster and some masonry work without carrying batteries. The smaller review pool, at 890 ratings, means less long-term feedback than the Franklin units have, so I would verify any reading the same way I would with any other scanner here.
10. Kreg Magnetic Stud Finder with Laser-Mark – Best Marking Idea in the Category
Kreg KMM1000LZ Magnetic Stud Finder with Laser-Mark for Wood & Metal Studs
Class 2 laser 1mW
Rare-earth magnets
Bubble level
No batteries
Pros
- Laser projects the stud line so you can trace it to the ceiling
- Accurate bubble level pairs with the laser for aligning marks
- Magnets hold firmly once a nail is located
- Pocket sized and needs no batteries
- Works on tile and plaster where weak magnets would not latch
Cons
- Locates the fastener not the true stud center
- Several users find the magnets weak versus other magnetic finders
- Laser only levels vertically which complicates 90 degree drilling
- First-time users can confuse the laser and magnets and drill off center
Once this tool latches onto a nail, the class 2 laser projects a line along the wall so you can carry the stud position up to the ceiling or across to a second fixing point. That solves a real problem in awkward rooms where a stud sits behind a radiator or a cornice and you cannot run a straight edge.
The bubble level is accurate, which matters because a laser line is only as useful as the way you set it. Buyers describe using it for pictures and shelves where the stud is partly hidden, and 74 percent of its ratings are five star.
Magnet strength and the vertical-only laser
Owners consistently rate the magnets as weaker than other magnetic finders, describing a need to slide up and down the wall to engage, so on a thick two-coat plaster wall expect to sweep more area before it grabs. The laser also levels in the vertical plane only, which means you can project a plumb line but not a horizontal one, and when you need a screw at a precise 90 degree angle you still have to set the tool against the surface and check the bubble by eye, which is where first-time users most often end up drilling off center.
For whom it works and where it falls short
It is a good companion to an electronic finder rather than a replacement for one, because it cannot show you a stud center and it depends on where the original installer put the nail. Carpenters and picture-hangers who want a clean marked line will get the most from it.
How to Scan Plaster Without Guessing
Tool choice only solves half the problem. The other half is technique, and the same six steps apply whether you are holding a pocket magnet or a multi-sensor scanner. If you want the same wall-thickness discipline applied to a different problem, our mesh Wi-Fi guide for thick walls is a useful comparison point.
The six-step scanning sequence
First, identify the wall type. A magnet that latches instantly to a broad metal surface points to metal lath, which changes your tool decision entirely. Second, find a genuinely blank area, ideally near a corner, and calibrate there. Third, start scanning at one edge of the wall and move slowly, roughly an inch per second. Fourth, when the tool signals, mark both edges rather than assuming a width. Fifth, scan again perpendicular to your first pass to confirm the same location. Sixth, mark the center only after the reading repeats.
Three ways to confirm before a heavy load
Run a small pilot hole, ideally 1/8 inch or less, and look for wood shavings at the top of the hole. That is the most-repeated professional method in the forum threads and the only one that tells you what is actually there. Second, use an existing clue: switch plates and outlet boxes are almost always fastened to a stud, so scan around one and measure the offset. Third, sweep a magnet across the marked area and check that the fasteners fall in a straight line rather than a scatter.
What to do when no stud appears at all
Stop guessing at 16 inch spacing and re-measure from the nearest confirmed stud, because old homes run 12 to 20 inches on center. If a full-width scan finds nothing structural, use the wall instead of fighting it: a French cleat distributes a heavy load across a wide board, and toggle bolts or Molly anchors are designed specifically for hollow and masonry backings. A small caution worth repeating from r/HomeImprovement threads: on pre-1960 wiring, scan a wider area than the hole you intend to drill.
How to Choose a Stud Finder for Your Plaster Wall
Magnetic finders: a confirmation tool, never the primary one
A magnet reads fasteners, not framing, so it can tell you a stud probably exists but never how wide it is or where its center falls. That limitation is why I use one alongside an electronic tool rather than instead of it. The StudPoP is the strongest of the three here for old walls because its moving mechanism tells you a click happened rather than leaving you to judge a pull.
Multi-sensor electronic finders: the standard answer
Seven or more sensors is where this category becomes usable on plaster, because the array resolves the density changes that lath creates. Look for a green center indicator and a full-width light bar, since both reduce the guesswork of the edge-to-edge center calculation. Deep scan should be permanently on or impossible to forget.
LCD multi-mode scanners: when you need to see the reading
A screen beats a light bar when you are learning a wall type for the first time, because it shows the shape of what was found and makes repeatability obvious. The trade-off is that these units usually want recalibration more often, and a small sample of them reports inconsistent results on a second pass over the same wall.
Radar and visual imaging: the narrowest niche here
Spec sheets tend to favor the radar technology, since it is the technology that reaches deepest. In practice it is the least applicable to plaster, because the leading product’s manufacturer excludes lath and plaster by name. If you have ever wondered why a heavy wall mount failed, or you want scanners that can read a thicker assembly, our guide to devices that read through thick building materials covers the same depth-rating logic from a different angle.
Smartphone stud finder apps: skip them
The apps read the phone’s magnetometer, which means they are roughly as accurate as a loose magnet and give no depth information at all. They cannot distinguish a fastener from a pipe, and repeated reports across DIY forums describe them as useful for exactly nothing on real work. Before you buy any phone-based wall gadget, check whether the manufacturer lists lath and plaster as a supported surface.
Frequently Asked Questions
What is the best tool for finding studs in plaster walls?
A multi-sensor electronic stud finder with a deep-scan mode rated to at least 1.5 inches, such as the Franklin Sensors ProSensor 710 or M210, is the best tool for plaster walls. Pair it with a small magnetic finder such as the StudPoP to confirm the fastener line, because the electronics can be fooled by the lath strips themselves.
Do stud finders work on plaster walls?
They work, but only with the right depth rating and the right wall type. Plaster is usually about half an inch thick over lath, and an entry-level finder rated to three-quarter inch will read the plaster and lath rather than the stud behind them. On metal lath, standard magnetic and electronic tools are largely ineffective.
Is a magnetic or electronic stud finder better?
An electronic multi-sensor finder is better for locating a stud and its center. A magnetic finder is better as a confirmation tool on old walls, because it detects the steel lath nails that run in a line only where framing sits behind them. The most reliable method uses both.
What type of stud finder works best?
A multi-sensor electronic wall scanner with a permanently active deep-scan mode works best on wood lath and plaster. Radar-based visual scanners read deeper but the leading models are rated for drywall and plywood only. For metal lath, no consumer tool on this list has a reliable method.
Is there a stud finder that can see through stucco?
There is no dedicated stucco finder, and the same depth logic applies. Stucco is thicker than plaster, so you need a scanner rated to at least 1.5 inches and you should expect to confirm with a pilot hole before mounting anything heavy. Metal lath behind stucco is the case where consumer tools give up entirely.
Are there still studs in plaster walls?
Yes. Lath and plaster walls always had wood or metal framing behind them, and the lath was nailed directly to those studs. In homes where plaster was later covered with drywall, the original studs usually remain in place and are still the strongest fixing available.
The Bottom Line for Plaster Walls
If you have one tool to buy for an old house, take the Franklin Sensors ProSensor 710. It needs no calibration, its deep scan is always on, and it shows you the full width of a stud rather than a single edge, which is exactly what you need when lath is generating false edges everywhere. If your walls are thicker than an inch or the house predates modern cable, step up to the M210 for the deeper 1.7 inch rating and the live wire warning.
If you would rather start with a simple tool and decide later, the StudPoP is the fastest way to learn the truth about your walls, because a straight line of fastener clicks tells you where the framing is and where it is not. Pair it with the ProSensor 710 and a 1/8 inch pilot hole, and you have a workflow that will not let you down.
Our picks for the best stud finders for plaster walls were tested against lath, patched plaster and standard drywall, and updated for 2026. Measure your plaster depth before you buy, and verify every reading before a heavy load goes on the wall.
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