Have you found yourself tackling a project that requires concrete floor resurfacing? A concrete grinder is an ideal solution for concrete restoration projects like removing coatings, residue, stains, and other unsightly imperfections. You may also use a concrete grinder to even out a surface or prepare the concrete for an overlaying finish.
If this sounds like your project, you may be asking yourself “how much will a concrete grinder remove?” Here’s everything you need to know about concrete grinders and the removal process.
How Much Will a Concrete Grinder Remove?
A concrete grinder can remove as much as you need it to, but it depends on several factors including the hardness of the concrete, your choice of diamond shoe and the length of time you are grinding.
Typically, the average concrete grinder will remove about one-sixteenth of an inch in one pass. If you find yourself working on a concrete floor with adhesives and finishes, you may execute more than one pass, as the first pass (and possibly the first few passes) is dedicated to their removal before grinding the concrete. Heavier-duty concrete grinders may offer up to one-eighth of an inch.
While there is no maximum of how much concrete you remove with a grinder, most projects don’t require more than one-half of an inch of removal. A one-half inch of concrete removal with a grinder can take six or more passes.
If you find yourself needing to remove more concrete in a shorter amount of time, perhaps a concrete scarifier is more suitable for your needs. You can always use both tools to first remove the concrete and then grind it to your desired finish.
The Concrete Grinding Process in 3 Simple Steps
While concrete grinding takes time and patience, it is possible for a beginner to successfully remove layers of concrete with the right guide. Here are three simple steps on how to use a concrete grinder.
Step 1: Prep the Floors
Preparing your floors is the first step to a successful concrete restoration project. For this step, you should start with cleaning the floors. A pressure washer can be a helpful tool to remove grime, paint drippings, and other surface imperfections. Make sure to completely clear the surface of small objects like nails, screws, or trash that can get in the way of the concrete grinder.
Before you start the next step, take a moment to evaluate the state of the floors. Are there any deep scratches, holes, or cracks? You may aggravate these blemishes with the concrete grinder if you don’t properly prep them. Take the additional time to fill in these imperfections with an epoxy filler and let it dry before moving on.
Pro tip: Prepare your concrete surface by cleaning the surface and filling in any deep cracks and scratches with an epoxy filler.
Step 2: Familiarize Yourself With the Machine
While many concrete grinders work similarly, you should always read the included instruction manual. As you get familiar with the machine, consider the type of project you are working on. Now is the time to choose the appropriate diamond shoe grit. A lower grit is ideal for removing layers of adhesive and other tough materials, whereas a higher grit will offer a polishing effect. It’s also worth noting that most concrete grinders have three settings.
One of the settings is for transport, the other for tooling (to install and remove the diamond shoe) and the last is for operation. Adjust your grinder to the tooling position and follow the manual to install your desired diamond shoe. Many machine handles are adjustable to your height so you can have better control while you’re working. Consult the manual on how you can adjust the machine to better suit your needs.
Pro tip: Read the manuals to learn more about different settings for transporting, tooling, and operating. Then adjust the machine’s height so you can comfortably control the grinder while working.
Step 3: Start the Grinder and Work Slowly
Before starting the machine, adjust the settings to the operating setting and ensure that the diamond shoe makes full contact with the concrete surface. If it’s not lying flat, it won’t grind or polish the surface evenly.
When you’re ready to start the machine, place a firm grip on the handle and tilt the machine slightly up so the diamond shoe isn’t in contact with the floor’s surface. Turn the machine on, then carefully lower the grinder to the floor and begin working. If the machine overheats, it will automatically stop. Give it some time to cool down, then repeat the process of turning it on and picking up where you left off.
Working at a deliberate pace will result in the best outcome. If you’re working with a single-disc or duel-disc rotary grinder, swing the machine from side to side as you slowly walk. Planetary grinders are a lot like pushing a lawn mower. Slowly walk forward and backward giving the machine enough time to do the bulk of the work for you.
Pro tip: As with many restoration projects, a slow and steady hand wins the race. Don’t rush through the project or you may end up spending even more time fixing your mistakes.
Safety Measures While Operating a Concrete Grinder
As with any piece of machinery, big or small, you should always wear the right gear and take proper safety precautions. Here are five safety tips to keep in mind:
- Wear eye protection. Safety glasses, eye shields, or safety goggles will protect your eyes from airborne objects and keep the dust out.
- Wear foot protection. Wearing work boots with thick, heavy soles and steel toes will protect your feet from sharp or heavy objects.
- Protect your hands and improve your grip with gloves. Work gloves will protect your hands from dust and can improve your overall grip on the machine for in-control steering.
- Use earmuffs or earplugs. Concrete grinders, especially when you’re using them in an enclosed area, are extremely loud. Wearing ear protection will safeguard your eardrums and save your hearing.
- Use respiratory protective equipment (RPE). Concrete grinding leads to millions of dust particles floating in the air, potentially harming the respiratory system. Use RPE with a protection factor of 20 or above.
Concrete Grinding FAQs
Here are the answers to some of the most commonly asked questions about concrete grinding.
How Long Does Concrete Grinding Take?
For your reference, a simple job can take around two hours to complete one pass on roughly 500 square feet of concrete. However, the time a project requires depends on several factors. To help answer this question, ask yourself these questions:
- How large is the surface area? The larger the area, the more time it will take.
- Are there small spots that require intricate work? You may need to budget extra time to account for the extra work you’ll put into removing these blemishes.
- Do you need to remove adhesives? Adhesives and floor finishes will require additional passes.
- Are you polishing the floor or preparing the surface for a sealant? Polishing may require additional time depending on the level of shine you desire. Preparing the surface for a sealant or adhesive may not take as long.
- How large is your concrete grinder? Larger concrete grinders will cover more surface area at one time.
What Kind of Finish Can I Get From a Concrete Grinder?
There are three common finishes you can achieve by using a concrete grinder.
- If you’re looking to add texture and traction to the surface, you can achieve a rough surface typically found on outdoor concrete slabs.
- If you’re planning to lay another material over the top of the concrete, you can create a slightly rough surface that will prepare the concrete, allowing the adhesive to bond.
- Lastly, you can achieve a smooth polished surface ideal for exposed concrete flooring.
What Are the Benefits of Grinding Down Concrete?
Concreting grinding is ideal for several reasons including, but not limited to, the following:
- Removing imperfections
- Preparing the surface for new flooring
- Polishing the concrete
- Removing residue
- Evening out the surface
- Removing old coatings and adhesives
How Much Does Concrete Grinding Cost?
The cost of concrete grinding depends on if you choose to hire a professional or if you rent or purchase a concrete grinder.
- Depending on the difficulty of the job, you could pay between three and 15 dollars per square foot for a professional.
- Renting a concrete grinder will require a deposit and a daily, weekly, or monthly rate. Many daily rentals cost less than $100 a day.
- As concrete grinders come in many different sizes, you can assume the prices to own a concrete grinder varies widely. A basic concrete grinder can cost as low as a few thousand dollars, whereas an industrial concrete grinder can cost upwards of $40,000.
Rent Concrete Grinders and Scarifiers
So, how much will a concrete grinder remove? While the general answer is one-sixteenth of an inch per pass, renting and using one for yourself may be the only way to get a definite answer. But rest assured that when you are resurfacing concrete, there is no better tool than a concrete grinder in the hands of someone willing to take their time to get the job done right.
When working on a project you haven’t done before, renting construction equipment like concrete grinders and scarifiers is a cost-effective way to add specialized machinery to your arsenal without paying large upfront costs. BigRentz offers rentable heavy machinery and other construction equipment to help you take on your projects with confidence. Check out BigRentz for all your future construction needs!