A thin (3 mm) cementitious micro-topping overlay needs a CSP 3-4 profile. Diamond grind the slab with a 30/46 grit metal-bond disc until the surface looks uniformly scratched and slightly open. Do not polish it; too smooth a surface prevents the overlay from bonding. Broadcast the overlay within 24 hours of grinding.
CSP (Concrete Surface Profile) is the ICRI visual scale from 1 (very smooth) to 10 (very rough). For a 3 mm overlay, CSP 3-4 means a clean, matte, uniformly scratched surface—like medium-grit sandpaper.
See the full range in our concrete grinding discs category.
| Overlay thickness | Target CSP |
|---|---|
| 1-3 mm micro-topping | CSP 3-4 |
| 3-6 mm self-leveler | CSP 3-5 |
| 6-12 mm thick overlay | CSP 4-6 |
| Resinous coating (epoxy/polyaspartic) | CSP 3-5 |
Shot blasting gives a good profile but leaves a more random texture. Diamond grinding is flatter and preferred for thin overlays over large floors.
Most 3 mm micro-toppings require a bonding primer. Follow the manufacturer's TDS.
Within 24 hours, ideally the same day.
Thin overlay lives or dies by the profile. Aim for CSP 3-4 with 30/46 metal bond, vacuum thoroughly, and overlay within 24 hours. contact JOY TECH for discs sized to your grinder.
