Metal detectors can find objects in concrete. The size of the search coil and the depth it’s rated to handle determines how well you can detect through cement.
What would you do if you had to find something lost under or behind concrete? Would you simply give up? Numerous specialized metal detectors can find various metal objects through thick cement.
Some of the objects it could find are rebar, plumbing, and electrical wiring. You could also discover lost valuables or hidden underground tunnels. Depending on the frequencies and wavelengths, metal detectors can help you to discern which is which.
It depends on the type of metal detector. If you are using a coin-operated machine, it is unlikely that it can pass through concrete. However, there’s a good chance that your device will go through the obstacle without issue if you’re using suitable models.
The magic is in finding the fine-tunings that work for your metal detecting goals.
In this article, I’ll explain how metal detectors work and the way to select those that read through concrete.
So, how do metal detecting machines work?
A metal detector sends out an electromagnetic field that then measures how things interact with that field. Metal objects will reflect the electromagnetic waves toward a metal detector.
It can also pick up those signals to figure out:
- What is there?
- Where is it located?
- Whether or not it’s ferrous/ magnetic? (lets you know if items entail steel)
Hence, some detectors can pass through cement bricks, but not all of them can. Some only use specific frequencies designed for different purposes, and they also need coils that will pick up the right signals to detect what item (or human body) it needs to find.
If you want a machine with these features, make sure your model has the right frequencies, coil types, and capabilities to detect through concrete.
What about tile floors?
A metal detector can also go through tile floors if the model has the necessary frequencies, coil types, and capabilities. Tile floors are less dense than concrete brick walls. Thus, the machine won’t need that many frequencies and coils.
Dense materials such as cement or tile flooring can block certain metal detector signals depending on what type of coil it has and how good it is at picking up specific frequencies. If a model does not pick up those signals, you will not know what is on the other side of these materials.
How deep can the metal detector detect through the concrete?
All metal detectors detect objects within the range of their sensing frequency. If the metal detector is strong enough to find valuable items across thick concrete barriers, it’s still limited to how far it can read.
Thus, it can detect all metals, but only if they’re close to the surface. What happens when you put a huge slab of concrete between your object and the sensor? You won’t get any results, even when there’s stuff buried underneath.
On average, the best metal detector for beginners can detect items through concrete at a depth of up to eight inches.
However, there are metal detectors that can go deeper than average models. Thus, you can detect objects all through a surface up to 20 feet in diameter!
This information is useful when trying to search under large surfaces or at extremely low frequencies. For instance, you would need to detect objects in a huge room or at low frequencies in the ground due to large steel structures.
So, the equipment you get determines the kinds of challenges you can overcome in your metal detecting endeavors. If you’re doing it like a pro, there’s a need to go for robust metal detectors with ample sensing frequency ranges.
Does the size of the search coil matter?
The size of your coil will determine how well it can handle obstacles such as concrete or tile floors.
Generally, the size of the search coil matters when you’re metal detecting, even when reading through cement. As a rule of the thumb, your metal detector covers more ground and becomes more sensitive when using bigger search coils.
If you’re just getting started, it’s best to buy a metal detector with an 11-inch coil. This way, you can cover more space and have more accuracy when locating items on the ground.
However, if you want more precision or deeper coverage in your search, opt for bigger coils that range from 18 inches up to even 36 inches in diameter. Thus, you can detect items that lie deeper and cover more ground, all through your search with just one sweep.
If you plan to use your metal detector daily or for professional purposes, then it’s best to choose one that can detect objects through thick concrete barriers (at least up to eight inches) and has coils with decent coverage of ground space.
Can a metal detector find rebar in concrete?
In most cases, it can. Both the metal detector and the rebar are ferrous metals. The rebar produces a magnetic field with its unique responses to detection equipment.
A metal detector is designed to find all types of metallic objects, including steel or iron-based products such as reinforcing bars (rebar.)
The ferrous metal that makes rebar is mild steel and approximately 98.0% to 99.0% iron, making it magnetic by definition.
When the concrete hardens, the rebar’s position in its matrix prevents other metals from passing through the material and absorbing some of the magnetism produced by the metal detector or other detection device for inspection purposes.
Your metal detector can find rebar in concrete if it can send and receive magnetic fields through cement.
The only way that a metal detector won’t detect the presence of steel or iron-based products like reinforcing bars (rebar) is if:
- There isn’t any present.
- The product was painted over.
- The material that the product is buried in absorbs all magnetic fields.
- It’s been completely encased.
These should be easy things to find out, though. A metal detector can detect rebar because it emits a magnetic field and finds everything within its radius, which carries a similar charge or response to detection equipment.
Can a metal detector detect through cement brick?
Some metal detectors can detect through cement bricks, while some cannot. What features and working mechanisms allow for this?
First off, you need a machine with the necessary frequencies to go through denser materials such as concrete or brick walls. Different types of metals have specific frequencies that they give out when being detected by a detector.
Second, you need a machine with the right type of coil to pick up those frequencies.
Third, unlike most detectors, your detector won’t need special add-ons if it has these features.
Tips for Detecting Metal through Concrete
The most cause of errors when metal detecting through concrete is getting false positives or misidentifying objects. With skillful analysis, you can choose from a generous selection of metal detectors for these endeavors.
The following tips will improve your effectiveness when metal detecting through concrete.
Tip #1: Invest in a Good Quality Metal Detector
A good-quality metal detector will do everything within its power to find any metals beneath the concrete. Using low-quality detectors will give inaccurate results.
So instead of spending on a cheap piece that will misidentify some metals as others, invest in a good metal detector. An effective detector gives you more accurate results, works in more depth, and is efficient with battery usage.
Tip #2: Keep the Metal Detector Moving
If you want to make sure that your metal detector is working fine, and keep it moving on different grounds. In this way, you will know if it works accurately or not. If it does, then there won’t be any misidentification of metals.
Moving your metal detector from one place to another will allow you to get a good idea of how far down each piece lies and what type of object it is.
Tip #3: Turn the Sensitivity Down
Turning the sensitivity down is another good tip for metal detection through concrete. It reduces electrical interference generated by other components in your metal detector.
If you reduce the sensitivity, it will provide accurate results for you without any trouble.
Tip #4: Test out Your Object on Concrete First
Before you investigate your object on concrete, test it first. You better avoid subjecting it to more tests if it doesn’t work well with the concrete. Testing will save you time and effort invested in the misidentification of metals beneath your concrete covering.
These are just some of the tips that you can use for metal detecting through concrete. A good quality metal detector, moving it around in different places, and carefully testing out objects will help you achieve your goals.
The Best Metal Detectors for Reading through Cement
When it comes to metal detectors, they aren’t usable on every surface.
Some are suitable for:
Some that can work both on land and underwater (waterproof.)
I researched and compiled metal detectors that effectively read through cement. To help many, I focused on waterproof devices.
So let’s begin with the top five best metal detectors for reading through cement:
5) Nokta Impact
It is both an all-terrain and waterproof device. You can submerge it up to ten feet. Despite being waterproof, it’s very resistant to water damage because of its built-in rubber coating.
It has a nice LCD and can ‘see’ up to nineteen inches deep in most cases, though the depth depends on what you want.
4) Teknetics Eurotek Pro
This metal detector is both all-terrain and waterproof. It too can be submerged up to ten feet, but this one is a bit more resistant to water damage because of its rubber casing.
This device has a nice LCD and can ‘see’ up to nineteen inches in most cases.
3) Bounty Hunter Gold Digger
If you are looking for something straightforward to use, then the Bounty Hunter Gold Digger is perfect for you. Its 3-coil system minimizes the amount of trash it picks up.
This device can see around nineteen inches deep in most cases, and despite being an all-metal detector. It even has some discrimination abilities. It may be an entry-level detector, but it is one of the best when it comes to reading through cement.
2) Garrett Ace 150
If you’re new in metal detecting and want an all-around device with good depth in most cases, then the Garrett Ace 150 is for you. It is waterproof up to ten feet and can, in most cases, see up to twenty inches deep.
It has a nice LCD, and since it is an all-terrain device, you can use it on land or water. It even has discrimination abilities, so you won’t find too much trash when reading through cement.
1) Minelab Excalibur II
The Minelab Excalibur II is probably the best metal detector when it comes to reading through cement. It can see up to three feet in most cases and has a nice LCD with built-in GPS.
There isn’t much about this device that I don’t like, but if I had to pick something, then it would probably be its weight (a bit heavy.)
So what’s the best metal detector? In my opinion, it is the Minelab Excalibur II because it can read through cement and has all-terrain abilities. It is simple to use as well, meaning beginners will love this device.
Metal detectors can find objects in concrete. The size of the search coil and the depth it’s rated to handle will determine how well you can detect items through cement. Steel-based products such as rebar are usually detectable.