How to Grind Concrete: Concrete grinding is one of the most common tasks in floor preparation — whether you’re removing old coatings, levelling a surface, or polishing concrete for a high-end finish. But knowing how to grind concrete properly is what separates a good job from a great one.

In this guide, we’ll break down:

• The step-by-step method for grinding concrete
• What equipment and tooling you’ll need
• The PPE required to stay safe
• Different types of floor grinders (and their pros and cons)
• Tips on choosing the right accessories for the job

Why Grind Concrete?

Grinding concrete removes surface imperfections, adhesives, paint, or sealers. It also opens up the concrete’s pores to allow new coatings or overlays to bond properly — or can polish the slab to a smooth, decorative finish.

What You’ll Need

1. Floor Grinder

Choose the right grinder for the job — more on this below.

2. Diamond Tooling

Select the right grit and bond hardness for your concrete type and desired finish.

3. Dust Control

A suitable industrial vacuum or dust extractor is a must to manage silica dust safely.

4. Hand Tools

An edge grinder or hand-held polisher for corners and hard-to-reach areas.

PPE for Concrete Grinding

Concrete dust is hazardous — always wear the correct PPE:

✅ Safety goggles or face shield
✅ Respirator or P3-rated dust mask
✅ Hearing protection
✅ Cut-resistant gloves
✅ Steel-toe boots
✅ Knee pads (if working low to the ground)

Step-By-Step: How to Grind Concrete

Concrete grinding is all about preparation, technique, and patience. Here’s a clear, expanded walkthrough so you get it right first time:

1️⃣ Prepare the Area

• Clear the work area of any furniture, debris, or loose materials.
• Tape off or mask areas you don’t want to grind, especially if you’re working in a domestic or commercial setting with sensitive finishes nearby.
• Ensure you have good ventilation, especially when working indoors.

2️⃣ Inspect and Repair the Slab

• Walk the slab to check for cracks, holes, or uneven spots.
• Fill any large holes or cracks with an appropriate concrete repair product.
• Mark high spots with chalk so you know where to focus extra passes.

3️⃣ Select the Right Tooling

• Choose your diamond segment based on the hardness of the concrete (hard, medium, or soft).
• For coating or adhesive removal, use PCD (polycrystalline diamond) tooling.
• For general grinding, start with a coarse grit (16–30 grit) to remove material efficiently.
• Progress through finer grits if you want to achieve a smooth or polished surface.

4️⃣ Connect Dust Control

• Attach your grinder to a suitable industrial vacuum or dust extractor with a HEPA filter.
• Make sure hoses are securely fastened and test suction before starting.
• This isn’t just about cleanliness — proper dust control keeps you compliant with silica regulations and protects health.

5️⃣ Set Up the Grinder

• Adjust the grinder’s weight settings if available — more head pressure helps with heavy removal, while less pressure can prevent swirl marks on softer floors.
• Level the grinder so all segments make even contact.
• Check the electrical supply if you’re using a larger 3-phase grinder.

6️⃣ Start Grinding: Work in Controlled Passes

• Begin at one corner and work methodically across the floor.
• Overlap each pass by at least 30% to avoid missed areas.
• Keep the grinder moving steadily — stopping in one place can create gouges if using a single head grinder.
• For high spots or tough coatings, apply more head pressure or make additional passes with coarser tooling.

7️⃣ Edge and Detail Work

• Use a handheld edge grinder or smaller walk-behind grinder to tackle edges, corners, and around columns or drains.
• Match the grit to your main grinder for a consistent finish.
• Take extra care near walls to avoid damage.

8️⃣ Inspect and Change Tooling

• Periodically stop to vacuum the floor and check progress.
• If you’re polishing, switch to finer grits gradually — each step removes scratches from the previous grit.
• Replace worn segments as needed to maintain speed and efficiency.

9️⃣ Final Cleaning

• Once grinding is complete, do a thorough final vacuum of all dust and debris.
• If you’re applying a sealer, ensure the surface is completely dust-free and dry for best adhesion.
• Safely pack away all equipment and dispose of dust in accordance with local regulations.

Pro Tip: Take Your Time

Rushing concrete grinding is one of the biggest mistakes contractors make. Patience, correct tooling, and methodical passes deliver the best finish — saving time and money on rework later.

Types of Floor Grinders: Pros and Cons

🔹 Single-Disc Grinders

• Best for: Small jobs, edges, residential work
• Pros: Lightweight, easy to transport, good for tight spaces
• Cons: Slower coverage, less powerful than larger grinders

🔹 Multi-Head Planetary Grinders

• Best for: Medium to large jobs, smooth finishes, polishing
• Pros: Even finish, faster, handles high spots well
• Cons: Heavier, requires more power

Tooling & Accessories: Choosing the Right Kit

✔️ Metal Bond Diamonds: Ideal for initial grinding and aggressive stock removal.

✔️ Ceramic or Resin Pads: Used for honing and polishing concrete to a high gloss.

✔️ PCD Scrapers: Perfect for removing stubborn coatings like epoxy or glue.

✔️ Edge Tools: Keep a selection of smaller diameter discs for perimeter and tight spots.

✔️ Weights & Shrouds: Adjustable weights can increase grinding pressure; good dust shrouds help with dust control.

Tooling Bonds Explained

The bond refers to the metal matrix that holds the diamond grit. The right bond ensures your diamonds stay exposed and cutting efficiently.
Here’s a quick guide:

• Soft Bond: Best for hard concrete (high Mohs rating). The bond wears away quickly, exposing fresh diamonds to keep cutting.
• Medium Bond: A good all-rounder for medium-hard concrete.
• Hard Bond: Ideal for soft concrete (low Mohs rating). Because soft concrete wears diamonds fast, a harder bond slows this wear so tooling lasts longer.

Choosing Grit and Bond

• For heavy removal on a hard slab (Mohs 6–7): Use a soft bond, coarse grit (16–30).
• For general smoothing on medium slab (Mohs 4–5): Use a medium bond, medium grit (30–80).
• For finishing or polishing soft slab (Mohs 3–4): Use a hard bond, fine grit (100+).

Always test in a small area and check wear patterns on your segments. If they glaze over or don’t cut effectively, you likely need to adjust your bond.

Pro Tip: Keep a Bond Variety on Hand

When hiring your grinder and tooling, ask for a couple of bond options — it saves downtime if conditions change unexpectedly. Our team at Multi-Hire can recommend the right mix for your site conditions.

Need Help?

✅ Need a Mohs tester? We stock them!
✅ Unsure what bond or grit you need? Just ask — our experienced team is here to make sure your hire package has everything you need for a smooth, efficient grind.

Final Tips

✅ Always test a small area first
✅ Keep spare diamonds on site — worn tooling slows the job
✅ Stick to manufacturer’s recommendations for your grinder and vac
✅ Hire what you need — it’s often more cost-effective than buying outright for one job!

Need the Right Grinder for the Job?

At Multi-Hire Power Tools, we stock a full range of concrete grinders, vacuums, and accessories to help you get the best results — plus expert advice on the right setup for your job. Hire what you need, when you need it — with full support from our experienced team.

📞 Ready to get started? Call us or drop by for a demo!