How to grind concrete smooth?

Saad Iqbal | 🗓️Modified: May 12, 2022 | ⏳Time to read:5 min

Are you ready to tackle the big concrete projects around your home? Whether you want to smooth out a rough concrete driveway or driveway border, or cover unsightly cracks in your walkway, grinding concrete smooth is the first step toward getting your project done right. But with so many options out there, how do you know which concrete grinder to choose?

When you work with concrete, you may be required to grind it smooth so that it has a uniform finish and surface. However, grinding concrete isn’t as easy as grinding other materials, such as metal or wood.

Concrete has a tendency to chip and crack during the grinding process, which can be dangerous if you don’t take proper precautions or follow certain steps while doing so.

Anyhow, concrete grinding is definitely something that you can do yourself with the right equipment and some persistence.

Here are the steps to grinding concrete smooth, plus some helpful tips to help you get the job done quickly and easily.

How do you grind concrete to make it smooth?

Of course all concrete can be polished, including pre-existing concrete which can be ground down and smoothed with the right devices and skills. Of course, the ease and difficulty of grinding concrete varies depending on the age of the slab. In general, older concrete is much easier to grind.

Preparation

Preparation is key when grinding concrete. The surface must be clean and smooth before application. You can sand down any rough areas or texture with a hand-held electric sander. Once you’ve finished preparing, sweep or vacuum up any sawdust. Then it’s time to start grinding.

Also Read: What is concrete grinding? How to do it? 

Cleaning the surface

The first step in smoothing concrete is ensuring that it’s clean. If there are any dirt, grease or oil stains on your slab, you should use a solvent cleaner like mineral spirits or paint thinner to remove them before polishing. (Even if you don’t see any of these contaminants, you should still spray down your floor with a hose and scrub with a stiff-bristled brush.)

Solvent cleaners will also help when it comes time to polish—the surface of concrete is porous, so wiping away liquids with dry rags won’t be enough. Soak up excess moisture after cleaning with either rags or newspaper.

Also Read: Types of Concrete Block used in Construction [PDF]

Grinding the concrete

A concrete grinder is a tool that spins and chips away at concrete. It has a diamond-sharp cutting head that cuts in all directions.

Grinders can be powered by an electric motor or gas engine. Most grinders come with an adjustable guard plate on top that keeps people from getting too close and accidentally putting their hands in harm’s way.

The ideal concrete grinder will have three distinct speeds so you can match it to your needs and material types: high speed for simple material removal, medium speed for soft or uneven surfaces, and low speed for hard surfaces or tight areas where precision is important. When grinding stone, marble, tile, brick or other difficult materials you’ll want a heavy-duty model capable of producing high torque without overheating easily.

How to grind concrete smooth?
How to grind concrete smooth?

Steps for concrete grinding

In order to grind concrete with grinder, first make sure you have a diamond disc that is made for grinding concrete. Without a diamond disc specifically made for grinding concrete, you may cause damage to your grinder, and possibly burn out your motor. Using an improper disc can also ruin a good blade by wearing it down too quickly and leaving deposits on it. It is recommended that you invest in quality equipment when doing any type of work with concrete or other masonry products.

Hold the grinder as flat as possible so that more of the grinding disk surface comes into contact.

Slope the concrete away from the lip or edge of the crack and use a dry hand grinder to make it level. The silica dust can be collected with a vacuum cleaner, but that is not always necessary when working outdoors.

You can also use a grinder with aggressive wheel. It removes more material and faster, but it leaves a rougher surface. In most cases, a less aggressive wheel means you’ll remove less concrete and leave a smoother surface.

How much can a concrete grinder grind?

A grinder cuts into surface coatings and the underlying concrete up to an eighth of an inch with each pass – a less destructive means than a concrete scarifier which may leave about a quarter of an inch of an imprint with each pass.

Cost to Grind Concrete Floor

To grind concrete can cost $1 to $4 per square foot. Grinding or sanding concrete removes adhesives and curing agents, opens up the pores, removes the smooth look, and flattens the surface. Thereafter, it makes the surface shine for a cost of $2 to $6 per square foot.

Saad Iqbal is a professional civil engineering and freelance write. He's passionate about structures, construction management, and home improvement topics. He's been working as a Senior Engineer in a consultant firm for over 8 years. Besides he loves writing informative and in-depth content focused on construction and home-related topics. You can catch him at his linkedin page or reach out via our contact us page.

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