Prepping Concrete Surfaces with Sandpaper for Paint or Epoxy (60, 120, 220, 400 Grit Guide)

Concrete may seem too tough for sandpaper, but proper sanding is essential before applying paint, epoxy, or sealers. By using the right grit sequence, you can smooth rough patches, remove stains, and create a surface that coatings adhere to securely. Whether it’s a garage floor, countertop, or patio, sanding makes all the difference.

Why Sand Concrete?

Raw concrete often has imperfections, laitance (a weak top layer), or residual coatings. Sanding eliminates these issues, levels the surface, and provides the right texture for new finishes. Without sanding, coatings may peel or fail prematurely.

Tools You’ll Need

• Heavy-duty orbital sander or floor buffer
• Vacuum with HEPA filter
• Protective mask and goggles
• Durable sandpaper sheets and discs

Best Grit Sequence for Concrete

• 60 grit (50-pack) — Cuts through coatings and roughens surfaces.
• 120 grit (25-pack) — Smooths scratches from coarse sanding.
• 220 grit (100-pack) — Prepares surface for epoxy or paint adhesion.
• 400 grit (50-pack) — Creates a refined finish for decorative concrete or countertops.

Step-by-Step: Sanding Concrete Surfaces

1. Prep the area. Remove debris and ensure the surface is clean and dry.
2. Start with 60 grit. Use 60 grit sandpaper for heavy removal of coatings or rough spots.
3. Smooth with 120 grit. Apply 120 grit sheets to even the surface.
4. Refine with 220 grit. Switch to 220 grit sheets to prepare for epoxy or paint.
5. Finish with 400 grit. Use 400 grit sheets for countertops or decorative concrete.
6. Clean thoroughly. Vacuum dust and wipe with a damp cloth before applying coatings.

Special Cases

• Garage floors: Focus on 60–120 grit for durability rather than high polish.
• Concrete countertops: Work through 220–400 grit for a satin or glossy finish.
• Outdoor patios: Stick to coarse grits for slip resistance.

Pro Tips

• Always use dust control—concrete dust is hazardous.
• Sand in overlapping passes for even results.
• Wet sanding reduces dust and helps with finer grits.

Aftercare

• Seal concrete after sanding to prevent staining and water damage.
• Reapply sealant every few years for protection.
• Clean with non-acidic cleaners to maintain finish.

FAQs

• Can I sand concrete by hand? Possible for small areas, but machines are better for efficiency.
• Do I need to sand before epoxy? Yes, sanding ensures adhesion and prevents peeling.
• Is polishing different from sanding? Yes—polishing goes beyond 800 grit into 1500–3000 for high gloss.

Watch & Learn

Sanding concrete with the right grit sequence ensures lasting results for both functional and decorative projects. Stock up on heavy-duty sandpaper sheets and prepare your concrete surfaces the professional way.