There has been a boom in recent years in house renovation circles. Due to changes in home improvement trends and advancements in tools, many choose to grind their floor. Whether in preparation for a type of flooring or to leave a gleaming cement finish, you may be wondering how long it will take you to grind your concrete floor. We consulted a variety of sources to find out the answer to this timely question!
The time it will take to grind your floor will depend on your experience, the tools you use, and the desired result. Using a standard walk-behind grinder, you should expect the following time frames per 500 ft of cement. The time spent on edges is generally not included.
- 2-3 hours for simple leveling jobs on standard concrete
- 4-6 hours for larger cement jobs or grinding down to an original cement floor
- over 7 hours for a shiny polished finish or removing tough sealants
Whether you are grinding your floor to prepare for painting or going for a pure polished cement look, you'll want to allow the right amount of time to get the job right. Keep reading as we discuss how to go about grinding your cement floor and factors that will affect the amount of time you'll need to accomplish your task.
How Long Does It Take To Grind And Seal Concrete?
Since the work area, construction of the cement, and tools you will use vary, it's easier to think of the job in 500 square feet increments. If you use a commercial company, they may be able to grind and seal 500 square feet in 3-5 hours.
If you choose to do the job yourself, it will depend on the type of grinder you use and what result you want to accomplish. Here are some commonly agreed time frames for grinding your own cement floor.
2-3 Hours For Simple Leveling Jobs
Passing a grinder to correct simple leveling issues or where a completely smooth finish is not necessary will take around 2 hours for 500 square ft. Read more about leveling a concrete floor in our article here.
For this type of work and work covering small areas, consider using an angle grinder.
4-6 Hours For Larger Jobs Or Grinding Down To An Original Cement Floor
Most users report that grinding down to an original floor for harder concrete could take up to 6 hours for 500 ft.
This would include larger jobs covering the same surface area but having more to remove, like certain glue types or other imperfections stuck in the cement.
For this type of work, you would want to purchase a walk-behind grinder. For small jobs where it would not be worth investing in your own grinder, you may be able to borrow or rent one.
Over 7 Hours For A Shiny Polished Finish Or Removing Tough Sealants
The heaviest, most intensive grinding jobs will involve multiple grinding disc changes as the grit gets finer. To get that glossy finish, you'll start with the coarsest grade, such as 30 or 40, and end with a 1500 to 3000 grit.
Professionals can pass up to 7 different times, each time going finer with the grit until the desired finish is achieved.
You'll also need to apply a densifier or concrete hardener to achieve the look in between passes. This will add to the total amount of time you'll want to allow for grinding cement floors to a high shine.
Consider getting a grinder with more than one head for larger polishing jobs to cut down the time it takes between passes. Users claim using a two-headed or more grinder for high shine jobs will be accomplished up to 5 times faster than a job done with a single head.
How Long Should Concrete Set Before Grinding?
Though concrete is considered dry after 48 hours and can be walked on, professionals recommend waiting 28 days for your floor to completely settle in before beginning the grinding process.
How Much Will A Concrete Grinder Remove?
Grinder blades are made from diamond or tungsten. These materials remove hard substances like concrete easily. Most grinders will remove anywhere from 1/16th of an inch per pass up to 1/8 of an inch.
If a floor needs more than this removed, consider pouring a brand new concrete floor.
Some users have experimented by adding weight in the form of sandbags to the top of the grinder to cut down on the total time spent on the job. A grinder that can utilize more power will also allow for faster work.
What Is The Best Way To Grind Down Concrete?
Depending on the finish you desire, the steps for grinding concrete can vary. Whether adding a high shine to a countertop or preparing a garage floor for epoxy, the base process for most DIY projects will be the same.
Sweep or vacuum the area clean and then pass the grinder in passes. If the area is larger, it may be helpful to work in 1oft by 10ft area to ensure even grinding across the surface.
If you are using more than one grit, change the disc with each pass. Always go from coarse to fine, increasing the grit with each pass.
Use Protective Gear When Grinding Down Concrete.
Dry cement can be dangerous to inhale, along with any surface chemicals stirred up in the process. Use a good face mask meant for welding, sanding, or grinding.
You'll also need to use goggles or work glasses and a dust shroud for your grinder for maximum protection. When choosing a dust shroud, make sure it specifies that it will work with the same size grinder you are using.
Choose the correct grit for the type of job you want to accomplish. This is the basic disc for grinding concrete, called a grinding wheel. Most grinding jobs will start with this disc for a 5-inch angle grinder.
How Much Does It Cost To Grind A Concrete Floor?
Doing minor or small grinding jobs yourself can save money! Factors that will affect your cost will be whether you rent or buy, the type of protective equipment you'll prefer, and the size of the job.
Spend $30-$300 For An Angle Grinder And Dust Shroud
If you are doing a base grinding job to fix minor imperfections and remove paint or other surface chemicals, you can purchase an angle grinder.
These run from roughly $30 to as much as $300 for a grinder with more than one wheel. Economize by getting a kit that already comes with the shroud and discs.
Get Good Protective Equipment For Under $70
A good respirator mask and protective glasses should cost $40-$70. Earplugs are also inexpensive and recommended.
Hepa Vacs Range From $99 To Over $600
Depending on what is included, the strength and versatility you'll need, a Hepa Vac for the dust starts at $99. This machine has an included power outlet for your grinder for added convenience.
Rent A Grinder For $140 To $1200 Rent A Walk Behind Grinder
If your grinding job is a one-time project, then consider renting a grinder. This would be cost-effective for big jobs. It would allow you to finish in less time but only pay for the time you are using the machine.
Home Depot rents equipment like this for $140 for 4 hours up to around $1200 for a week. Be sure to put in your zip code for exact rates and availability for your area.
How Much Does It Cost For A Professional To Grind The Floor?
If the job seems big and complicated, don't worry! Some professionals specialize in floor grinding. Popular estimate sites state you can expect to pay 1 to 4 dollars per square foot for grinding services.
Factors that affect the price include how finely you need the floor ground and its condition at the start point. We recommend getting estimates from a few companies as prices can and do vary widely.
Schedule Your Grinding Project For Convenience And Safety
Now that you know how to figure out how much time you'll need to allow for grinding your floor, try and schedule your project in a low traffic, uninterrupted timeframe.
Decrease distractions to have a safe working environment to ensure your floor is ground the right way the first time!
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