A critical part of every flooring installation,... coatings application,... overlayment applications,... as well as moisture mitigation systems is the preparation of the concrete surface to be covered. this is often referred to as "Surface Profiling"... in this article we will cover the 4 most common ways to profile concrete along with the pros and cons of each method...
THE METHODS…
- Diamond Grinding
- Shot-Blasting
- Scarifying
- Shaving
METHOD #1…DIAMOND GRINDING
Diamond grinders come in a variety of configurations, from single head grinders to multi head machines, each with strong and negative points... Attached to these machines are a variety of different grit diamond segments (See below) that give different degrees of roughness to the surface of the concrete or…CSP… (CONCRETE SURFACE PROFILE)
METAL-BOND DIAMOND TOOLING
The pros of a diamond grinder are…
- Smooth, consistent floor
- Consistent and repeatable surface
- Removes contaminates from the surface
- Levels high spots
- Wider variety of materials can be removed
- Ability to not just grind concrete but polish it to a glass like finish
- Uses no caustic chemicals
- Grinding is dust free when grinding wet or using the correct dust extraction equipment
The cons of a diamond grinder are…
- Grinding can be very slow
- Diamond segments can be expensive
- Learning curve, you must learn how to select the correct diamond segments for a specific project (see link below)
- Segments can be damaged by protrusions like bolts and conduit
- The process of grinding “imbeds concrete dust… a bond breaker… into the surface and must be removed
- Large Diamond Grinders require a lot of power, at least 230 3 phase and more often 480 3phase
FOR MORE INFORMATION ON GRINDER TYPES CLICK HERE
CLICK GERE FOR MORE INFORMATION ON CORRECT DIAMOND SELECTION
METHOD # 2 SHOT-BLASTING
Shot blasting concrete is a resurfacing process that uses millions of small steel beads referred to as “shot”... this shot is dropped onto a "Blast Wheel" rotating at a very high rate of speed that throws the "Shot" onto the surface of the concrete and "blasts” away the surface of the concrete as well as removes tough debris, coatings and contaminants from the surface... a "Shot-Blaster" must be connected to a dust extraction system, this system removes the debris created but allows the "Shot" to return to the hopper to be reused.
Shot-blasters come in a variety of sizes and power configurations, the size and scope of your project will determine which machine would be best for you.
The pros to a Shot-Blaster are…
- Fast production rate on most floors
- The floor is 100%clean after the process, needing only a quick sweep with a magnet brush to remove stray shot
- Uses no chemicals
- Low cost per square foot
- Dust free
- No wait time after profiling to coat the floor
- Removes loose or weak material, even below the surface layer of concrete
- Easily control the profile by varying the shot size, amount of shot released and speed of the machine
The cons of Shot-Blasting are…
- Can leave blast lines, cornrowing and can possibly “Telegraph” through thin mill coatings
- Because Shot-Blasting removes the weaker areas, the floor will be rougher, with a more inconsistent surface
- Shot-Blasting typically does not work well on thicker Elastomeric coatings, materials that are not “Brittle” impedes the efficient rebound and recycle of the shot
- Because of potential injury, A high degree of attention must be given to PPE, Personal Protective Equipment to not just the operator but EVERYONE in the general area of the working equipment
- Large Shot-Blasters require a lot of power, at least 230 3 phase and often 480 3phase
FOR A DETAILED UNDERSTANDING OF SHOT BLASTING CLICK HERE
METHOD #3 SCARIFYING
Scarifiers or sometimes referred to as planers & milling machines… These machines have a drum with a variety of multi tipped tipped cutting wheels, this tooling is mounted loosely on the drum and is designed to “Flail” or “Pummel” the concrete surface... The tooling spins at a high rate of speed and impacts the surface of the concrete and breaks that surface away. This concrete debris is then removed with a high CFM dust extraction unit. Scarifying is a very effective method of profiling concrete and achieving a high CSP level… This method is defiantly one that has it’s PRO’s and CON’s
The pros of a Scarifier…
- Quickly achieves an aggressive CSP profile
- Relatively inexpensive way to achieve the high CSP profile
- Great for removing high spots in concrete like frost and root heave
- On Some models you can customize the drum for slip resistance patterns
The cons of a Scarifier…
- Scarifying is hard on the surface of concrete, it produces micro fractures in the concrete itself.
- Flooring instulation contractors as well as coating and moisture guard applicators never want to go over a scatified surface as there is always a great amount of surface preparation needed to get it acceptable for material installed and coatings applied
- Large Scarifiers require a lot of power, at least 230 3 phase and often 480 3phase
- Contractor use a lot more material, like epoxy coating to cover scarified surfaces,... manufacturers love it because they get to sell a lot more product.
METHOD #4 CONCRETE SHAVERS…
Concrete shavers are a lot like the scarifyers, they have a drum as well. But unlike a scarifier that “Flails”, or impacts the concrete, a shaver “Cuts” the concrete with a series of diamond blades. These machines can remove an incredible amount of material in a single pass, up to an inch at a time! Because of this, they require the biggest dust extraction systems to keep up with the debris produced.
The pros of a concrete Shaver are…
- Incredibly fast material removal
- Completely dustless operation
- Highly versatile, the drum is customizable and can cut as wide or narrow a path as the project calls for. Even load the drum so it will produce a pattern in the floor for nonslip surfaces
- Remove high spots and ridges in concrete
- Great for joint repair and spalling repair
- Will remove any surface with the correct tooling
- Quickly produces a high CSP
- Some concrete shavers can be changed from a shaver to a scarifier like the Bartell Global CT320 shown above
The cons of a concrete Shaver are…
- The machine, the vac system and the tooling are expensive
- The power requirements are high, most large machines are 480 3phase
- Big machines and big vac systems can be a challenge to mobilize
- With all specialized equipment, there is a learning curve. Equipment training is recommended
THATS THE FOUR. SO, CHOOSE YOUR METHOD...
- Diamond grinding
- Shot-Blasting
- Scarifying
- Shaving
Each concrete profiling method is great and has its place. Also, each has their pros and cons, but with a little research you can decide which method is correct for your projects…
If you have questions regarding the correct method and machine to profile the concrete floors on your project give one of our local distributers or us a call here at Bartell Global and one of our reps can help get you the correct machine for your projects. 425-405-9100
Last, related, and important point…
As contractors it is critical that we understand the importance of Concrete Surface Profile… CSP… because, whether we are installing material over a concrete surface, coating it with epoxy, applying a moisture mitigation system, or polishing the concrete surface, all manufacturers of materials and mastics that are adhered to concrete requires concrete to be profiled to the correct C.S.P. Concrete Surface Profile
CLICK HERE FOR A COMPLETE UNDERSTANDING OF CSP
CHART SHOWING C.S.P.