How to Sand Concrete

By James Draper·How I choose the sanders I recommend

Updated on October 1, 2026

To sand concrete, use diamond abrasives, not ordinary sandpaper: a diamond cup wheel on an angle grinder or concrete surfacer for leveling and removing coatings, resin-bond diamond pads from 50 up to 400-3000 grit for smoothing and polishing, and a silicon carbide rub brick for small patches by hand. Keep the surface wet or run the tool through a shroud and vacuum, because concrete dust contains crystalline silica.

I’ve spent months working with concrete surfaces and tested many sanders on them, and this guide covers everything I’ve learned: how to sand concrete floors, slabs, steps and countertops, which sandpaper and pads actually cut concrete, what grit to use for each finish, whether a regular sander will do the job, and how to keep the silica dust under control. Product details come from the manufacturers’ own listings and spec sheets, and the dust rules come from OSHA’s silica standard for construction.

How to Sand Concrete: Tool and Abrasive by Job

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Can You Sand Concrete?

Yes. I’m often surprised how many people assume a rough or stained slab can’t be restored. Concrete can be sanded, ground and polished, but the abrasive has to be harder than the stone and sand in the mix. That is why “sanding concrete” in practice means diamonds: diamond segments on a cup wheel for heavy work, and diamond particles held in a resin pad for smoothing and polishing. The only conventional abrasive that does useful work is silicon carbide, and only by hand on small areas or for a light scuff.

Sanding vs Grinding vs Polishing

The three words describe the same process at different grits. Grinding uses a coarse diamond cup wheel to take off coatings, glue, high spots and the weak top layer of the slab. Sanding is the in-between stage that removes the grinding scratches, usually with resin-bond pads around 50 to 200 grit. Polishing continues with finer pads, often 400 and up, until the surface turns satin or glossy. Most DIY jobs stop at sanding, because a sealer or coating goes on top. Countertops and feature floors go on to polishing.

When Not to Sand: Structural Damage

Sanding fixes surface problems: rough trowel marks, form lines, stains, efflorescence, thin coatings and small patched areas. It does not fix the cause of wide or growing cracks, sections that have heaved or sunk, or spalling that exposes rebar. If a crack runs through the slab or the two sides sit at different heights, have it looked at before you grind it flat, or you will only hide the symptom.

Sandpaper for Concrete: What Actually Works

Search for sandpaper for concrete and you’ll find four very different products. Here’s what each one is for.

Diamond Cup Wheels (Grinding)

A cup wheel is a steel dish with diamond segments brazed or sintered around the rim. It threads onto an angle grinder or a concrete surfacer and cuts concrete, paint, mastic and thinset fast. Double-row and turbo segment patterns are the common ones for surface work. Cup wheels leave a coarse, swirled scratch pattern, so they are the first step, never the last. Pair one with a shroud and vacuum indoors (see the dust section below).

Resin-Bond Diamond Pads (Sanding and Polishing)

These are the real concrete sanding pads. Flexible hook-and-loop discs, usually 4″ or 5″, with diamond powder held in resin, sold in grit sets that run from about 50 to 3000 or higher. They go on a backer pad on a variable-speed polisher or grinder and work best wet. Each grit removes the scratches of the one before, exactly like sandpaper on wood. Speed matters: the SPTA set below lists an optimal speed of 2,200 RPM, far below the 11,000 RPM of a typical angle grinder, which is why a variable-speed polisher gives a better result than a fixed-speed grinder.

Silicon Carbide Sandpaper and Rub Bricks (By Hand)

Silicon carbide is harder than the aluminum oxide in most woodworking paper, which is why it’s the grain in wet/dry sheets such as 3M Wetordry. On concrete it works for a light scuff before paint or sealer and for cleaning up a small repair. For anything rougher, a rub brick is the hand tool masons use: a block of coarse, fluted silicon carbide that knocks down form lines, fins and patch edges.

Why Regular Sandpaper Fails on Concrete

Standard aluminum oxide sandpaper and the hook-and-loop discs you use on a random orbital sander are made for wood, paint and filler. On concrete the grains dull and the paper loads with stone dust within minutes, so you spend money on discs without changing the surface much. If the job is bigger than a scuff, move to diamond.

What Grit Sandpaper for Concrete?

Match the grit to the finish you want, not to the tool you happen to own.

• Coarse cup wheel: coating removal, leveling, opening up a sealed or troweled surface before an epoxy or overlay.
• 50-100 grit pads: remove the cup-wheel scratches and smooth a rough slab. Enough before most penetrating sealers.
• 200-400 grit pads: a smooth, honed, satin surface. A common stopping point for floors and outdoor countertops.
• 800-3000 grit pads: increasing shine. Pad sets for countertops typically include 800, 1500 and 3000; the SPTA set adds 6000 for a high gloss.

Don’t skip more than one grit between steps. The scratches from 50 grit will still be visible at 400 if you never ran 100 and 200 in between. For wood and other materials, the sandpaper grit chart covers the full CAMI and P scales.

Can You Use a Regular Sander on Concrete?

Only for light work, and it depends on the sander.

Random Orbital Sander

A 5″ random orbital sander can scuff a concrete surface with silicon carbide or diamond hook-and-loop discs before paint, or smooth a small patch. It won’t level a slab or remove a coating in any reasonable time, and concrete dust is hard on a wood sander’s bearings and switch. If you already own one, it’s fine for a countertop edge or a scuff; don’t buy one for concrete. For wood, my random orbital sander reviews cover the best options.

Belt Sander

A belt sander isn’t a concrete tool. The belts are made for wood, they wear out almost immediately on stone, and the open belt throws silica dust everywhere. Use a cup wheel instead.

Angle Grinder and Concrete Surfacer

These are the right tools. An angle grinder with a diamond cup wheel and a dust shroud handles patches, edges and small slabs. A dedicated concrete surfacer (Makita calls its PC5010C a “concrete planer”) does the same job with a bigger motor, adjustable speed and an integrated shroud, which makes it more comfortable for a garage or basement floor.

How to Sand Concrete Step by Step

I’ve found that breaking concrete sanding into deliberate stages makes the whole project manageable and produces consistently professional results.

Step 1: Clean and Inspect the Surface

Sweep and vacuum, then degrease oil stains. Pull out nails, staples and anchors that could tear a pad. Fill cracks and holes with a concrete patching compound, let it cure fully per the product’s instructions, and plan to grind it flush with the surrounding slab.

Step 2: Set Up Dust Control

Mask doorways, vents and built-ins with plastic sheeting, connect the shroud to a vacuum or set up a water supply, and put on a P100 respirator, eye and ear protection. The next section explains the rules.

Step 3: Grind or Sand the Coarse Pass

Start with the cup wheel if you’re removing a coating or leveling, or with the coarsest pad (around 50 grit) if the surface is only rough. Keep the tool flat and moving in overlapping passes. Resting in one spot cuts a dish into the slab.

Step 4: Work Up Through the Grits

Move to the next pad only when the previous grit’s scratches are gone everywhere. Clean the surface between grits: a loose coarse particle under a fine pad leaves a deep scratch you’ll have to go back for.

Step 5: Clean Up the Slurry or Dust

Wet work leaves a gray slurry. Pick it up with a wet/dry vacuum or squeegee before it dries back onto the surface, then rinse. For dry work, vacuum with a HEPA-filtered vacuum rather than sweeping.

Step 6: Let It Dry and Seal

Let the concrete dry completely, then apply the sealer or coating you sanded for. Follow the sealer’s own instructions for dry time and moisture limits; a penetrating sealer for floors and driveways and a food-safe sealer for kitchen countertops are different products.

Wet or Dry? Controlling Silica Dust

Concrete contains crystalline silica, and grinding it makes respirable dust. OSHA’s construction silica standard (29 CFR 1926.1153) sets the permissible exposure limit at 50 µg/m³ over an 8-hour average, and its Table 1 spells out the controls for each tool. For handheld grinders on concrete it allows two routes:

• Water: a grinder with an integrated water feed that continuously wets the grinding surface (OSHA lists this option for outdoor work).
• Shroud and vacuum: a commercially available shroud with a dust collector that moves at least 25 CFM per inch of wheel diameter, with a filter of 99% efficiency or better and a cyclonic pre-separator or filter-cleaning mechanism. For a 4-1/2″ wheel that’s about 113 CFM. Indoors, Table 1 adds a respirator with an assigned protection factor of at least 10.

OSHA writes these rules for employers, but they’re the best available guide for a homeowner too. For any indoor concrete sanding, wet sanding is what I strongly recommend. In practice: wet-sand pads whenever you can, use a shroud and a vacuum with a good filter for dry grinding, and wear a P100 respirator such as the 3M 6391 half facepiece kit, which comes with 2091 P100 filters. A regular shop vac with a basic filter will pass fine dust straight through; see my guides to the best dust extractors and shop vacs for dust collection.

The Concrete Sanding Tools I Recommend

Makita PC5010C 5″ SJS II Compact Concrete Planer

Best Tool for Concrete Floors and Slabs

A dedicated 5″ concrete surfacer built around a cup wheel. Makita lists a 12.0 amp motor, a variable speed dial from 4,000 to 9,000 RPM, constant speed control that adds power under load, and an integrated dust extraction shroud. Its SJS II drive uses a leaf spring and cam gear to cut vibration on long runs. The variable speed is the point: you can slow it down for resin pads and run it faster with a cup wheel. This listing is the tool with the shroud; the PC5010CX1 kit version adds a diamond cup wheel.

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• ✅ Built-in dust shroud
• ✅ Variable speed for cup wheels and pads
• ✅ Low-vibration drive
• ❌ Premium price tier
• ❌ Overkill for a single small patch

Best For: Garage and basement floors, coating removal and slab prep.

DEWALT DWE402K 4-1/2″ Angle Grinder

Best Budget Concrete Grinder

An angle grinder is the cheapest way to sand concrete with diamonds. DEWALT lists an 11 amp, 11,000 RPM motor, a Dust Ejection System that pushes debris back out of the air intake, a quick-change wheel release, a one-touch guard that rotates 360 degrees, and a paddle switch with a lock-off. Fit it with a shroud and a cup wheel for grinding. At a fixed 11,000 RPM it’s a grinding tool, not a polisher, so resin pads need a variable-speed polisher.

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• ✅ Affordable entry into diamond grinding
• ✅ Tool-free wheel changes
• ✅ Useful for cutting and grinding afterward
• ❌ Fixed speed, too fast for polishing pads
• ❌ Needs a separate shroud indoors

Best For: Patches, edges, steps and small slabs.

HERZO Universal Surface Grinding Dust Shroud

Best Shroud for an Angle Grinder

The shroud turns an angle grinder into a dust-controlled concrete sander. HERZO says it fits most 4-1/2″ and 5″ grinders with a 48-51 mm front collar, takes cup wheels 15-25 mm thick, and has a swivel slide cover that opens so you can grind flush to a wall. Connect it to a vacuum with a high-efficiency filter; the shroud only captures dust if the vacuum behind it can move enough air.

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• ✅ Fits most 4-1/2″ and 5″ grinders
• ✅ Flush-cut edge cover
• ❌ Check your grinder’s collar size first
• ❌ Only as good as the vacuum behind it

Best For: Grinding concrete indoors with an angle grinder.

KSEIBI 644030 4-1/2″ Diamond Cup Wheel

Best Diamond Cup Wheel for Concrete

A double-row segmented diamond cup wheel for 4-1/2″ angle grinders. KSEIBI lists it for grinding concrete, stone and screed and for removing thinset, glue and epoxy, with 5 mm segments that can run wet or dry. Double-row wheels cut fast but leave a coarse surface, so plan to follow with pads if you want it smooth. Confirm the arbor matches your grinder’s spindle before you order.

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• ✅ Fast removal of coatings and high spots
• ✅ Wet or dry use
• ❌ Coarse finish on its own
• ❌ Aggressive for beginners on thin overlays

Best For: Leveling, coating removal and grinding patches flush.

SPTA 4″ Diamond Wet Polishing Pads Set (50-6000 Grit)

Best Concrete Sanding Pads

Resin-bond diamond pads in a full grit run: SPTA lists 50, 100, 200, 400, 800, 1500, 3000 and 6000 grit, plus a hook-and-loop backer with a 5/8″-11 thread. The pads are 4″ across and 3 mm thick, rated for granite, concrete, marble and tile, with an optimal speed of 2,200 RPM (12,000 maximum). SPTA says they can run dry but work best with water. Stop at 400 for a honed surface or carry on to 3000 and 6000 for a gloss.

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• ✅ Complete grit sequence in one set
• ✅ Backer pad included
• ✅ Works wet for low dust
• ❌ Needs a variable-speed polisher for best results
• ❌ Small pads for large floors

Best For: Concrete countertops, sills, steps and polished edges.

Bon Fluted Rub Brick, 20 Grit Silicon Carbide

Best for Sanding Concrete by Hand

The masonry answer to a sanding block. Bon’s brick is 6″ x 3″ x 1″, made of fluted 20-grit silicon carbide, with a plastic handle. Rubbed in circles over damp concrete, it knocks down form lines, fins, trowel ridges and patch edges without any power or dust cloud. It’s slow on large areas, but nothing is quicker to grab for a step, a post base or a single repair.

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• ✅ No power, no dust cloud when used wet
• ✅ Handle saves your knuckles
• ❌ Slow on anything larger than a patch
• ❌ Coarse finish only

Best For: Form lines, steps, edges and small repairs.

The Marshalltown rub brick is the same idea without a handle: 6″ x 3″, fluted, 20 grit.

Large Floors: Rent the Machine

For a whole garage or basement, a handheld tool means hours on your knees. Rental shops carry walk-behind concrete grinders with diamond tooling and vacuum ports, and OSHA’s Table 1 covers those too: water fed to the cutting surface, or the manufacturer’s dust collection system. Ask the shop which diamond tooling suits your slab (hard or soft concrete, coating or bare) and whether they rent a matching dust extractor. Keep the handheld grinder or surfacer for edges and corners the big machine can’t reach. If the floor is wood rather than concrete, my floor sander guide covers the right machines.

Common Mistakes When Sanding Concrete

Over the years, I’ve watched people rush concrete sanding and regret it. Here are the patterns I see most often:

• Using wood sandpaper. Aluminum oxide discs dull and clog in minutes. Diamond or silicon carbide only.
• Polishing pads at grinder speed. Resin pads overheat and glaze at 11,000 RPM. Use a variable-speed polisher near the pad maker’s recommended speed.
• Skipping grits. Jumping from 50 to 400 leaves the coarse scratches in place under a shiny surface.
• Letting slurry dry. Dried slurry bonds back to the surface and has to be sanded off again.
• Sealing damp concrete. Moisture trapped under a sealer causes cloudiness and peeling. Follow the sealer’s dry-time instructions.
• Dry grinding without a shroud. The most common and most harmful mistake, covered above.

Final Thoughts

Sanding concrete is diamond work. Choose the tool by the size of the job, choose the grit by the finish you want, and treat the dust as the real hazard it is. With a cup wheel for the heavy pass, resin pads for the smoothing, water or a shroud for the dust and a sealer at the end, a rough or stained slab can be brought back to a clean, even surface. I’ve seen damaged driveways and garage floors come back to life once properly sanded and sealed.

Working on a specific surface, a countertop, a garage floor or steps? Ask in the comments: I read every one, and I’ll point you to the right setup.