Quick Answer

A typical concrete floor grind takes about 15-40 minutes per 100 m² per grit pass with a planetary grinder, depending on machine size and floor condition. A full grind-and-polish cycle (25 grit through 1500 grit) usually runs 3-5 working days for a 1,000 m² warehouse with a 3-head 32-inch machine.

What Drives Grinding Time

Three factors decide the hours: machine width and head count, concrete hardness and condition, and the number of grit steps. A wide planetary machine covers more per pass; hard or heavily coated concrete needs slower passes; and a polished finish needs every grit step done properly.

Productivity Reference Table

Estimates for a standard 25-to-200-grit grind with diamond grinding tooling:

• Hand grinder / angle grinder (small areas): 3-6 m² per hour
• Single-head 8-inch grinder: 15-25 m² per hour
• Three-head 24-inch grinder: 60-100 m² per hour
• Three-head 32-inch planetary: 100-150 m² per hour
• Large ride-on grinder: 200-350 m² per hour

These numbers assume one operator, dry grinding, and medium-hard concrete in reasonable condition. Add 30-50% time for repair grinding, heavy coatings, or deep contamination.

Plan the Passes, Not the Hours

Break the job into passes: one for repair leveling, then one per grit step. On a 1,000 m² floor that is roughly 8-10 passes of the machine across the whole surface, plus edge work with a hand grinder along walls and columns. Edge grinding usually adds 10-15% to the total time.

How to Speed Up Safely

Use the largest machine the space allows, keep the tooling sharp by matching bond to concrete hardness, and avoid rework by checking each pass under raking light. Skipping grit steps to save time creates swirl marks that take longer to fix than the pass you skipped.

Frequently Asked Questions

Q: How long to grind 200 m² with a 24-inch grinder?

A: About 2-3.5 hours per pass, or roughly 10-18 hours total for a five-grit grind-and-polish sequence including edge work.

Q: Why is my grinding taking twice as long as estimated?

A: Check the bond hardness, machine speed, and whether the floor has coatings or high spots. A softer bond on hard concrete glazes and cuts slowly; heavier contamination adds passes.

Q: Does wet grinding take longer than dry?

A: Wet grinding is usually slightly slower per pass but can reduce dust and extend tool life. Productivity is comparable; the tradeoff is cleanup time.

Conclusion

Time your floor project from the productivity table above, add a margin for repairs and edges, and never trade grit steps for speed. Accurate planning up front is what keeps a grinding job on schedule.