You should find a stud or two behind a ceramic wall for tasks like hanging a towel rack, mounting a shower grab bar, deciding where to place shower controls, or even installing a soap dish. While finding studs behind drywall is easy, it’s harder behind ceramic or porcelain tile.
Ceramic tile walls are thicker than drywall and may have cement boards, uncoupling mats, different fasteners, thinset layers, pipes, and even metal studs. So finding studs is more challenging. Each tool can only do the job perfectly. However, some tools and techniques can help you locate the studs in a ceramic wall.
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Dielectric Constant Stud Finder
A dielectric constant (DC) stud finder is a battery-operated tool for locating studs behind wall surfaces. When you slide it across a wall, it lights up a red signal to show a solid mass behind the surface, like a wooden stud.
First, place a strip of painter’s tape horizontally across the area to use it on a tile wall. Then, move the stud finder slowly across the tile surface, above or below the tape, from one side to the other.
Mark any spot on the tape where the stud finder gives a positive alert, even if it’s a weak signal. As you make multiple marks, you may notice a pattern. Areas with several pencil marks, such as a stud, likely indicate something dense behind the tile.
While DC stud finders can be unreliable on tile walls due to false positives from dense materials, they can be helpful when combined with other techniques to locate studs.
Rare Earth Magnets
Rare earth magnets are highly sensitive and strong magnets that can be used to find studs. You can glide them over a surface to detect metal fasteners underneath. While metal fasteners don’t hold tiles, the cement board substrate beneath them often is.
With patience and careful, slow movement, you can detect a fastener. This method works especially well if the substrate beneath the tile is thinner than usual, which can happen if the tile thinset isn’t uniformly thick due to how it’s applied with the tiler’s float.
Handle rare earth magnets with care. They should be kept far from each other and away from metal objects. Rare earth magnets are very strong and can pinch or cut skin or break bones if not appropriately handled.
Finding Studs with Intuition and Investigation
Wall studs are usually spaced every 16 inches on-center. Start from a room corner and measure off 16 inches, marking that point. This gives you an initial idea of where a stud might be.
On-Center: This term means measuring from the center of one stud to the center of the next.
To fine-tune your search for a stud:
- Drill Through Grout: Use a small drill bit to drill through the tile grout. Make sure to drill deep enough to go through the grout and the cement board.
- Probe the Hole: Use a finish nail to feel if there’s a stud behind the tile.
- Drill More Holes: If needed, drill additional holes to accurately locate the stud.
- Find the Stud: Consistent resistance when probing with the nail indicates a stud.
- Mark the Stud Location: Place a piece of painter’s tape on the tile to mark the stud’s position.
- Cover the Holes: Later, fill the pilot holes with a bit of grout.
Ultra Wide Band (UWB) Scanner
For finding a stud behind drywall, a UWB scanner is expensive and excessive. But for thick, dense, or otherwise problematic materials like dry or wet concrete, floor heating ducts, or metal, UWB scanners are indispensable. Instead of searching for metallic fasteners, UWB scanners use radar technology. They can find studs behind thick tile and other materials with surprising ease.
UWB scanners are powerful enough that since their introduction, the Federal Communications Commission (FCC) has required operators of UWB scanners to register their devices at various times. Borrowing or renting a UWB scanner is certainly an option if you want to find studs behind the tile easily.
However, buying one is another matter; most DIYers need to handle larger projects to justify the expense of a UWB scanner for their tool shed.
Attach Item to the Tile Face
For lighter items like soap dishes, drilling into studs is unnecessary. These can be easily installed right on the tile surface using epoxy, avoiding the need to locate studs and drill holes.
How Does a Stud Finder Work?
A stud finder works by detecting differences in electrical properties or the density within the wall. Some stud finders can also locate a stud by using a magnet to identify screws or nails in the stud. Others use an electrical current to measure the electrostatic field within the wall. Some can also scan for electrical wires that are secured to the stud.
Depending on the type of stud finder you decide to use, whether you use magnets, electricity, or even radar to find the stud, the important thing is locating a stud to anchor whatever you’re hanging securely.
Choosing the Right Stud Finder
When selecting a stud finder, it’s helpful to understand the different types available. Here are the three most common stud finders you’ll find on the market:
- Magnetic Stud-Finders:
– These finders use strong internal magnets to detect the screws fastening the drywall.
– They alert users with a flashing light or beeping sound when they locate these fasteners.
– They work best when the drywall screws are attached to the studs.
– Caution: Inaccurate readings can occur if some screws missed the stud.
– Usage Tip: Move the stud finder slowly and steadily for the best results.
- Electronic Stud-Finders:
– These use dielectric sensors to detect changes in the wall’s density.
– More advanced than magnetic types, they can find PVC piping, wiring, and studs.
– They’re effective even through thicker materials like ceramic tiles, which can be challenging for magnetic finders.
- Radar Stud-Finders:
– These are among the most modern and high-tech options utilizing radar technology.
– They can locate studs, pipes, wires, and even rebar in concrete.
– Given their versatility and accuracy, they tend to be more expensive than magnetic or electronic finders.
Ensuring Accuracy with a Stud Finder
Using a stud finder correctly is crucial for accurate results, regardless of the type. Here are steps to follow for effective use:
- Check the Batteries
– Essential for all types: magnetic, electronic, or radar.
– Ensure batteries are fresh to guarantee accurate readings.
– Replace old or weak batteries.
- Calibrate the Stud Finder
– Place the tool flat against the wall and hold the power button for 1-2 seconds.
– This adjusts the tool to the wall’s specific conditions.
– Read the owner’s manual for device-specific calibration instructions.
- Finding a Stud
– Slowly move the calibrated stud finder over the wall.
– Wait for the alert indicating a stud has been found.
– For drywall, confirm by tapping on the wall: a solid sound indicates a stud, while a hollow sound suggests no stud.
- Mark the Stud
– Once a stud is located, mark it with a pencil or chalk.
– Use a ruler for straight lines, aiding in the precise placement of items.
- Repeat for Additional Studs
– If hanging heavy items like shelves, multiple studs may be needed.
– Studs are typically 16 inches apart on-center.
– Measure from the first marked stud to find additional ones.
– Repeat the process until all necessary studs are marked.