Concrete Polishing: 50?100?200?400?800?1500?3000 Grit

Concrete floors can be more than gray slabs—they can shine like stone with the right sanding ladder. Professional polishing uses progressive grits: 50 ? 100 ? 200 ? 400 ? 800 ? 1500 ? 3000. Each stage removes scratches and densifies the surface, leaving a glossy, durable floor.

Why Polish Concrete

Polished concrete resists dust, stains, and wear. It reflects light, brightens spaces, and reduces maintenance. Skipping grits leaves swirl marks or dullness. The full sequence ensures clarity, strength, and a professional finish.

Tools & Materials

• Diamond sanding pads or 9×11 in sheets (50–3000 grit)
• Planetary grinder or orbital floor machine
• Vacuum with dust shroud (or wet grinding setup)
• Concrete densifier (lithium or sodium silicate)
• Polishing compound or guard
• PPE: respirator, ear protection, knee pads

Recommended Grit Sequence

• 50 grit — Heavy cut, removes coatings and levels surface.
• 100 grit — Smooths 50 scratches, begins clarity.
• 200 grit — Refines surface, matte finish.
• 400 grit — Satin sheen, prepares for densifier.
• 800 grit — Semi-gloss, increases reflectivity.
• 1500 grit — High-gloss prep, tightens surface.
• 3000 grit — Final gloss, mirror-like finish.

Step-by-Step: Concrete Polishing

1. Prep floor. Remove coatings, fill cracks, and patch holes.
2. Grind at 50 grit. With 50 grit (25-pack), cut down high spots and open pores.
3. Step to 100 grit. Switch to 100 grit (50-pack). Grind evenly until floor feels smoother.
4. Refine at 200 grit. Use 200 grit (100-pack) for matte finish base.
5. Polish at 400 grit. Switch to 400 grit (25-pack). Achieve satin finish and prep for densifier.
6. Apply densifier. Roll or spray evenly; let cure per instructions.
7. Move to 800 grit. Sand with 800 grit (50-pack) until semi-gloss appears.
8. Refine at 1500 grit. Switch to 1500 grit (100-pack). Floor should now gleam.
9. Final polish at 3000 grit. Finish with 3000 grit (25-pack) for mirror finish.
10. Seal or guard. Apply protective coating for stain resistance.

Special Cases

Soft concrete: Requires densifier earlier (after 200 grit).
Exposed aggregate: Sand slower to avoid uneven polish.
High traffic floors: Extend polishing to 5000 grit for maximum durability.

Pro Tips

• Vacuum thoroughly between grits—dust scratches if left behind.
• Grind in overlapping passes for even finish.
• Always apply densifier before moving past 400 grit.
• Don’t rush—clarity builds slowly, not instantly.
• Protect floor immediately after polishing to maintain gloss.

Aftercare

• Clean with pH-neutral cleaners only.
• Reapply guard or sealer annually.
• For touch-ups, re-polish starting at 800 grit upward.

FAQs

• Why start at 50 grit? Coarser removes coatings and levels uneven slabs.
• Do I need densifier? Yes—it hardens surface and boosts gloss retention.
• Can I stop at 800 grit? You’ll get semi-gloss, but full gloss needs 1500–3000.
• Does polishing weaken concrete? No—densifier strengthens surface during process.

Video: Concrete Polishing Process

Closing: Concrete can shine like stone. With 50 ? 100 ? 200 ? 400 ? 800 ? 1500 ? 3000 grit sanding plus densifier and sealer, floors gain stunning gloss and long-lasting durability.