You've probably asked yourself the following question several times before drilling a hole into your wall: how do professionals not go through pipes or cables? The answer is simpler than you might think, and no, they don't know where each and every cable passes through. They have a stud finder to make sure they're only drilling your walls.
Also called stud detectors or stud sensors, these devices are very precise equipment that allow you to make all the reforms you want in complete safety. In the following guide, we'll tell you all you need to know about this tool, and you'll discover our ranking of the best models available on the market.
- 1 Weekly newsletter with the best personal finance tips
- 2 Key Facts
- 3 Ranking: The best stud finders
- 4 Shopping Guide: Everything you should know about stud finders
- 5 Shopping Criteria
- 6 Summary
- Stud finders are extremely precise devices. They must be calibrated and you should follow various maintenance rules if you want them to last.
- Not all stud finders can detect every single material. Make sure to read the manufacturer's specifications before buying one. You'll have to pick a specific model if you want to look for plastic, for instance. Otherwise, you'll just be throwing money away.
- Modern stud finders are very easy to use. They all feature Liquid Crystal Display (LCD) screens that clearly show you the readings. Some models even show the direction in which you have to move to find the material you're looking for.
Ranking: The best stud finders
Sometimes, something as simple as hanging a photo can turn into a real nightmare if you drill a pipe or cable. Having your own stud finder at home is the best way to work safely at all times. That way, you can check where these elements pass through and you won't have to be afraid of drilling them anymore. In the section below, you'll discover our own selection of the best stud finders on the market right now.
Shopping Guide: Everything you should know about stud finders
What is a stud finder exactly?
These detectors were born in the United States around 40 years ago. Their performance has naturally developed and improved over the years. Nowadays, we have access to stud finders that work electronically and via radar. These modern systems allow the tools to find a greater variety of materials, as well as indicate the depth at which they are found.
What are the components of a stud finder?
They have several of these sensors, which depend on the materials that your tool is designed to detect. These different sensors can find:
- Electrical cables (regardless of whether they carry current or not);
- Three-phase voltage cables (from electric stoves, for example);
- Low-voltage cables (doorbell and phone cables);
- Pipes, bars and beams of all types, both ferrous and non-ferrous metals (steel, aluminum or copper);
- Reinforced steel;
- Wooden beams;
- Hollow spaces;
- Plastic pipes and tubing.
How does a stud finder work?
|Type of sensor||Function|
|Detection of metal and wood beams||They are detected using capacitive sensors. The detector generates an electric field that penetrates up to 4 cm. The beams have a greater influence than empty spaces.|
|Detection of live wires||They work by means of sensors of 50/60 Hertz (Hz). The sensors act as receivers and detect the signal at a depth of 5 cm. They are suitable for detecting cables with voltages from 110 to 230 volts (V). They cannot detect neutral wires, grounding or telephone cables.|
|Detection of ferrous and non-ferrous metals||They work using an inductive sensor. This sensor locates and identifies non-ferrous and ferrous metals. Both types of metal are determined by phase-shift analysis.|
|Radar sensors||Used in the most sophisticated models, they detect all of the elements mentioned above, but at greater depth.|
What are the uses of a stud finder?
- Masonry: They can detect through bricks, aerated concrete, pumice stone, and limestone.
- Concrete: It can be reinforced or otherwise.
- Partition walls: A type of lightweight construction.
- Various surfaces: Plastered surfaces, tiles, wallpapers, hardwood, and carpets.
- Steel plates (Drywall)
Are there limitations to using stud finders?
It is also very important to remember that various factors can affect the measurement result and lead to false readings. This most often occurs under unfavorable circumstances such as:
- Partition walls formed by several layers of material;
- Empty plastic pipes and wooden beams located in cavities and lightweight construction partition walls;
- Objects placed on the wall at an angle;
- Nearby devices that emit strong magnetic or electromagnetic fields, such as mobile phone stations or generators.
How should I use my stud finder?
Here is a quick step-by-step guide on how to use your stud finder:
- Remember that, due to the way the tool works, the upper edges of objects across the direction of travel will be more easily detected. This is why you should explore the area of interest in two perpendicular directions.
- Set the device to the mode you need (metal, cable, wood) and place it on the wall. A light will turn on, indicating that it is working but hasn't found anything.
- Move the stud finder along the wall, or toward where you think there may be a cable or pipe. When approaching, a light will come on or emit an acoustic signal. The display will show the approximate distance and direction in which you should search.
- If you're looking for wiring, remember that the detector only works with those livewires.
- If you need to mark where the electrical conduction or water pipe runs, insert a pencil into the hole (all stud finders have one on the upper part), and move it following the material.
- Once you're done using the tool, wipe the base plate — the part in contact with the wall — with a dry cloth, and store the device.
What should I do regarding false positives?
You should always read the instructions and check that the tool's sensors are compatible with the material you want to find. If you're seeing many objects displayed on your screen, for instance, it is very likely that the wall has several holes. This is why a stud finder capable of identifying hollow bricks can be extremely useful.
Recent advances in technology have contributed to the great improvement of stud finders. You should be very clear about your needs if you want to buy the model that best fulfills them. Ultimately, all you want is a device that is useful to you. In the following section, we'll go over some key aspects to keep in mind when purchasing your very own stud finder:
- Type of construction
- Type of technology
- Calibration mode
- Indication of the center of the object
- Detection modes
- Detection depth
Type of construction
You can still find buildings with bricks (solid or hollow) and concrete. However, the drywall method has slowly taken over in recent years, and it offers a number of advantages. This type of construction will require a stud finder capable of finding holes, nails, and wooden beams.
On the other hand, you can stick to traditional (and cheaper) devices when working on masonry constructions where metals and power cables are mostly hidden. Please keep in mind that most modern plumbing use plastic, which means that you'll also need a tool for that.
Type of technology
The type of construction you're working in will largely determine the technology and price of your stud finder. A tool capable of finding cable, metal, wood, and plastic will be much more expensive than a traditional ultrasonic technology device that only works for wood, metal, and livewires.
Modern stud finders work best on thick or double drywalls because their ultrasonic waves can bounce off neighboring areas. Electronic devices, on the other hand, work best with thinner, plaster walls. They are also very useful to detect all types of ferrous and non-ferrous metals.
The calibration carried out prior to the measurement is the decisive factor in the reading quality of your stud finder. This calibration allows the tool to measure the thickness of the wall and the surface to be analyzed, and the density of the material. It also evaluates factors such as humidity, temperature, and even the accumulation of static electricity formed when holding the stud finder.
You may need to calibrate your tool manually following the process indicated by the manufacturer. Some models, on the other hand, integrate automatic calibration systems, which has several advantages. You can use these devices immediately and detect objects with greater accuracy and fewer false positives. This is why we encourage you to opt for a model with automatic calibration.
Indication of the center of the object
Most stud finders have a feature that locates the edges of beams and other objects. This means that you have to mark with a pencil the whole right and left edges using the point that your device first identifies. Some tools also feature a technology that directly points to the center of the object.
These models with accurate center marking make your work easier and can save you a lot of time. If you want to locate wooden beams to drill, for instance, you should always do so at the center of the beam. In that case, a stud finder with this function will naturally be your best option.
The vast majority of stud finders are equipped with various preset detection modes. All you therefore have to do is select the one you need for each new task. As we mentioned earlier, the most basic models can detect beams, metals, and livewires. Some can also identify non-ferrous metals.
The more expensive a model is, the more functions it will offer. You can find detection modes for underfloor heating, lightweight partition walls, concrete, and hollow bricks. Certain devices have a default universal mode that is designed for all types of masonry and can detect cable, metal, wood, and plastic.
All stud finders can identify the location of materials hidden behind surfaces. However, not all are capable of indicating the depth to which those objects are found. The most advanced models available on the market will also show the maximum depth at which drilling is considered safe.
Manufacturers always indicate the maximum depth (e.g. 150 mm). Keep in mind that this depth will vary depending on the material that you're looking for.
Wooden beams are generally detected at the shallowest depth — around 40 mm. On the other hand, metals — in particular ferrous ones — can be found at a greater depth, sometimes exceeding 15 cm.
The arrival of screened framing detectors led to a real breakthrough in terms of material detection, identification of the type, and thickness of the material detected. The very best models can even tell you the depth at which the material is found or the maximum depth of drilling. Most devices feature a simple, user-friendly interface.
Models with backlit screens are great because they allow you to work in low visibility conditions. Some also integrate signals to help you locate the material. By telling you in which direction you should move your stud finder to identify the material, they make your life much easier.
When you buy a stud finder, you're investing in your safety. Knowing where different materials are hidden behind a surface allows you to easily mark them and do all kinds of holes, cuts, repair work, and DIY jobs without worrying about drilling through a pipe or cutting a livewire.
Before making your purchase, make sure you know exactly what material you'll be looking for: metals, wood, livewires, plastic, or even holes. If you feel it is needed, don't hesitate to opt for a model that offers other functions, too. These may include displaying the depth at which a material is found, or the maximum drilling depth.
(Source of featured image: Sergiy Tryapitsyn: 18289848/ 123rf.com)