Guide to Concrete Coring

Guide to Concrete Coring In Edmonton

Concrete core drilling or coring is the process of removing a cylinder of concrete from the rest of the structure.  Coring can be done on concrete floors, walls and ceilings and the process is typically used for more complicated tasks from coring concrete pile caps to removing unwanted concrete from a property.

​Concrete coring has many applications across a range of industries such as:

  • Plumbing
  • Electrical
  • Drainage
  • Manholes
  • HVAC
  • Structural testing
  • And much more…

Depending on the requirements, an unlimited range of coring diameter sizes can be drilled and can be done up to virtually any depth.

What is concrete coring?

Concrete coring utilizes a diamond cutting drill to cut a perfect round hole in any concrete structure. The process is low-noise, dust free and non-percussive which means that it is the most popular choice when it comes to cutting.

​With our concrete coring process, holes can be drilled at any angle, whether vertical or horizontal.  We are also able to accommodate for drilling in sensitive locations or confined spaces with use of electric or hydraulic rigs.

How does Concrete Coring work?

A concrete coring or drilling tool is made up of a diamond cutting end attached to a steel tube. In most cases, the rig is attached to the floor or surface using an anchor, bolt or vacuum seal in order to stabilize it.

As the rig drills, the cutter is cooled by water in order to reduce friction. Once the coring process is completed, the concrete slug is removed, leaving a perfect hole with no cosmetic damage or requirement for after care.

​It is always important to scan the area prior to cutting to ensure that there is in the way of the drill such as rods or conduits.

Find out more about concrete scanning.


How to ensure efficient Concrete Coring

Core drilling is not a simple undertaking especially of an operator is unsure of how to go about it. There are a number of unknown factors that can arise and with this, it is difficult for an inexperienced operator to know what they may be getting into. A core drill, core bit, water hose, anchor, electric cords, wrenches and appropriate Personal Protective Equipment (PPE) are ready to go however, core drillers often find it is not just about having all the necessary equipment to do the job, but what is more important is that they have the training and knowledge to use the equipment safely and correctly to achieve the required results.

There are four steps that all operators should consider before starting to core.



When drilling with a wet core bit, one of the most important factors is obviously water. It is sometimes considered that the more water used, the better, but this is not correct. With the use of the diamond cutting drill, the diamonds work on grinding away the concrete and the water helps to form concrete slurry by mixing with concrete dust and debris. The slurry that is created actually helps the grinding process by not only keeping the core bit cool, but also making sure the diamonds remain exposed by allowing the bit to come into contact with particles in the slurry. When it comes to water volume, there are two things to consider:

  1. Too little water can result in not being able to create a slurry and thus the diamonds will continue to grind the same particles.
  2. Too much water can cause all the concrete dust particles to be washed away, leaving nothing to help keep the diamonds exposed.

For best results, operators should apply water until the slurry begins to look like heavily-creamed coffee. This consistency proves to be the most effective when wet core drilling.



Proper rig anchoring is key to insure a straight core. The recommended method for anchoring the drill rig is using physical anchors rated for core drilling. It is also important that the proper tools and techniques are used to ensure the optimum results. Another option is using a base vacuum if applicable.  With this option, you need to ensure that the surface is smooth and the vacuum gasket is in good working order. It is not safe to use a vacuum base when drilling into a wall or ceiling. Always make sure that the vacuum filter bottle is free of water or debris, as the presence of either will compromise the vacuum. A vacuum gage is recommended to ensure that you have a visual indication that an adequate vacuum is available for drilling.

Many rigs also have a ceiling jack that allows the operator to shore the top of the mast up to an overhead area with a sturdy piece of wood allowing for more stability. It is never recommended to stand on a rig to hold it down, as this is a very unsafe practice. Standing on a rig can cause a ‘ribbing’ effect on the core and will eventually cause the bit to bind up in the hole.



Setting a motor to the correct revolutions per minute (rpm) could be the difference between grinding properly and glazing the diamond segments. Different bit diameters require to be run at different speeds for optimum results and therefore should be run at their specified rpm. The smaller the bit diameter, the faster the bit should be run and the larger the bit diameter, the slower the rpm setting. Many electric core drills have multiple speeds, so an operator is able to use different size core bits and operate them at the appropriate speed.



In order to maintain the correct drilling speed, the operator needs the necessary amount of power to do the job. The majority of core drills are electric-powered and it is recommended that an amp meter is used when drilling with this type of core drill. Operators should look to push the drill motor to its maximum rated amperage, but not exceeding it. Exceeding the rated amperage of the motor can result in lower productivity due to the motor becoming bogged down. Operating the motor at a higher rate than its maximum amperage will cause the internal components of the electric drill motor to overheat and wear prematurely. The same principles also apply when drilling with a hydraulic motor. It is important to maintain the correct flow to ensure the correct drilling speed is being maintained.

Core drilling can be a daunting task for anyone not familiar with the process.

Here is some additional information on the tools necessary for Concrete coring.

For any advice related to concrete coring or drilling, contact Michael at Walser Contracting Ltd!


Walser Contracting Ltd.
Concrete Cutting & Coring Services
15C Alberta Ave, PO Box 3816,
Spruce Grove, AB T7X 3B1

Monday to Friday: 6:30am to 4:00

Call: 780-721-3405

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