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Yes — diamond grinding is the fastest, most complete way to strip old epoxy, polyurethane, mastic and glue from a concrete floor. Use PCD (polycrystalline diamond) tooling such as the WerkMaster PCD coating-removal disc on a walk-behind planetary grinder to peel the coating in sheets, then switch to metal-bond trapezoid shoes such as the triple-round-segment grinding disc to clean the residual film and open the concrete. Finish by HEPA-vacuuming and re-grinding to CSP 3-4 for the new coating. Chemical strippers are slower, smellier, and rarely get the glue out of the pores.
Chemical strippers (methyl chloride, soy-based, caustic) soften a coating over 4-24 hours, then you scrape it up — but they leave residue in the concrete pores that the new coating cannot bond through. They also require ventilation, PPE, and disposal as hazardous waste. Diamond grinding cuts the coating and the surface layer together, leaving a clean, open, mechanically profiled floor ready for immediate recoat. On a 500 m² warehouse, a grinder strips and preps the floor in a day; chemicals take three.
There are two tool families and you need both. PCD (polycrystalline diamond) blades are razor-sharp carbide-diamond segments that shave or peel soft coatings — epoxy, PU, paint, mastic, carpet glue, VCT adhesive. Metal-bond diamond shoes cut hard concrete, not soft resin. If you put a metal-bond shoe on an epoxy floor, it will skate over the resin and glaze. If you put PCD on bare concrete, it will chew it up too aggressively. Use PCD first, then metal-bond to clean and profile.
| Coating | First tool | Second tool | Final |
|---|---|---|---|
| Thin epoxy / paint <0.5 mm | PCD | 60/80 metal-bond | 120/150 |
| Self-leveling epoxy 2-5 mm | PCD | 30/40 metal-bond | 120/150 |
| Mastic / carpet glue | PCD with scraper bar | 60/80 | 120/150 |
| Urethane cement topping | Scarifier + PCD | 16/20 metal-bond | 60/80 |
Mount the PCD tooling on your planetary grinder. Run the machine at slow walk pace — do not push. The PCD segments bite into the coating and peel it in rolls. You will see a line of curls ahead of the machine; that is the coating coming off. HEPA-vac the floor at the end of each strip. On thick 5 mm self-leveling epoxy, expect two passes: first pass at a 5° angle to score, second pass flat to remove. Switch to metal-bond shoes once 90% of the coating is gone; the remaining thin film needs diamond grinding, not PCD.
Once the old coating is off, you are looking at a floor that is contaminated with residual resin in the pores. Switch to 30/40 metal-bond trapezoid shoes, grind until the surface is uniformly opened, then step through 60/80 and 120/150. The triple-round-segment trapezoid disc is a good all-rounder; for very hard concrete, use a softer bond. After profiling, the floor should read CSP 3-4 — tactile, uniform, and free of any glossy patch where coating remains.
The walk-behind grinder leaves 10-15 cm along walls, columns, expansion joints, and doorways. Use a diamond cup wheel on an angle grinder with a vacuum shroud. For thick coatings on edges, switch to a small PCD cup wheel. Do not leave un-stripped edges — the new coating will delaminate there first.
Yes. PCD tooling strips mastic and carpet glue effectively. If the mastic contains asbestos (pre-1980 buildings), treat it as regulated abatement — do not dry-grind without licensed containment and HEPA negative air.
Run a wet white rag over the floor. Any residue will show as a coloured streak. Walk the floor in raking light — glossy patches are residual film. Grind those spots again with metal-bond until the surface is uniformly matte.
On very thick (10 mm+) toppings, a scarifier first is more efficient than chemicals. Chemical strippers leave residue that contaminates the new grind. Skip them and go straight to PCD.
CSP 3-4 for self-leveling epoxy, CSP 4-5 for broadcast or urethane cement. The goal is a uniform, open surface with no residual glossy patches.
Removing old coatings by diamond grinding is faster, cleaner, and better for adhesion than chemicals. PCD peels the film, metal-bond shoes clean and profile, and the floor is ready for recoat the same day. It is hard on tooling but the alternative — chemical strippers, scraping, and a failed recoat — is harder on your schedule and your reputation.
Written and reviewed by JOY TECH — an SGS & BV audited, CE/RoHS certified diamond tools manufacturer founded in 2004, exporting to 50+ countries.
Our factory and QMS are audited by SGS and Bureau Veritas. Products meet CE/RoHS requirements and every piece is 100% inspected before packing.
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