The short answer
Polished concrete is not one pass with a machine; it is a sequence of passes, typically six to ten trips across the whole floor with progressively finer diamond tooling, plus densifier, joint filling, and a final burnish. Estimating templates in completed-work records price grinding production at about 32 square feet per man-hour on small jobs and about 45 square feet per man-hour on large ones, because big open floors let crews run efficiently while small floors carry the same setup over fewer square feet. A typical job, a few hundred to about 3,000 square feet, ran a crew of four for four to seven days once repairs, edges, and joints are counted. What stretches a schedule is rarely the grinding. It is slab condition, repairs, power, and how much of the building you can hand over at once.
The pass sequence, and why it sets the schedule
Each step below is a complete pass over the floor, which is why square footage times passes, divided by crew production, is the honest way to think about duration.
| Step | What happens | Schedule note |
|---|---|---|
| Metal grind, 40, 80, 150 grit | Coarse diamonds open the surface, remove coatings and high spots, set aggregate exposure | The slowest, heaviest passes; old overlays and repairs are discovered here |
| Transitional, 100 grit | Bridges from metal tooling to resin tooling | Removes metal scratches before refinement starts |
| Resin grind, 200 and 400 grit | Refines the surface toward its final sheen | Densifier is typically applied in this range, once the surface is open |
| Densifier and guard | A silicate densifier reacts with the concrete to harden it and stop dusting; a guard adds stain protection | Needs dwell and dry time inside the sequence, not after it |
| Higher refinement, 800 to 1500 grit | Only on higher gloss specifications | Each added grit level is another full pass at finer production |
| Joint filling | Control joints are filled with semi-rigid polyurea | Often scheduled late so grinding does not tear fresh filler out |
| Burnish, 800 to 3000 grit pads | Final high-speed pass that sets the finished gloss | Fast, but only possible once everything before it is done |
A standard specification in the records runs exactly this pattern: 30 grit metal to start on rougher slabs, a 100 grit hybrid resin transition, densifier, a 400 grit resin finish, guard, and a 1500 grit burnish. Count the passes in any proposal you receive. A bid that reaches the same sheen in suspiciously fewer steps is planning to skip refinement you will see later as scratches, because grinder scratches needing regrinding are a recurring callback in the records.
The production rate math, honestly
Work an example with the template rates. A 2,000 square foot floor at 32 square feet per man-hour is about 63 man-hours of grinding production, roughly two working days of machine time for a crew of four. Yet typical jobs of this size in the records ran four to seven days on site. The difference is everything that is not grinding: mobilization and protection, edge work the big machines cannot reach, crack and spall repairs, joint filling, cleanup between passes, and waiting on access to the next area. When you compare schedules, ask what besides grinding the number includes, because that is where estimates quietly diverge.
Larger floors genuinely are faster per square foot, which is why the template rate rises to about 45 square feet per man-hour in the 10,000 to 20,000 square foot range: long straight runs, fewer edges per square foot, and setup spread over more area.
What speeds a job up, and what stretches it
- Slab hardness and condition. Soft or dusty slabs grind fast but refine poorly and drink densifier; hard slabs slow every pass. Heavy crack patching in the records was significant enough to need change orders.
- What is on the slab now. Old coatings and overlays that turn out thicker than expected are the classic schedule break; one job slipped about a week on this alone. Budget a test grind in the worst area.
- Repairs and joints. Every foot of joint filling and every patch is crew time that is not grinding. Repair-heavy floors should be scheduled as repair jobs with a polish finish, not as polish jobs.
- Access and phasing. Production rates assume the crew owns the floor. Phasing around operations, nightly moves, and partial handovers all cut effective production, sometimes in half, and no template rate survives them unchanged.
Power planning: the 480 volt question
Large grinders and polishers typically run on 480 volt three-phase power. Confirming that power exists, and who provides the connection, belongs at the top of the pre-job checklist, because the alternative is a generator, and generators are a documented failure point: in a single year in the records, five polished concrete jobs hit generators overheating or failing on site, each one stopping production cold. If your building cannot supply 480 volt power, plan the generator deliberately, sized for the equipment with ventilation and fueling thought through.
Mock-ups, flatness, and exposure: set expectations before the crew arrives
Mock-ups. A polished mock-up, a small area taken through the full sequence, is how sheen and aggregate exposure get agreed before thousands of square feet are committed. Expect one; on large or high-visibility work, expect more. The records include a job that needed three mock-ups before award. That is not dysfunction, it is how appearance arguments get settled cheaply.
Flatness. Polishing refines the surface; it does not flatten the floor. Standing specification practice in the records requires the slab to be FF 50 or better, FF being the standard F-number measure of floor flatness, because a wavy slab polishes into a wavy shiny slab, with gloss pooling visually in the low areas. If your floor’s flatness is unknown, measure it before promising anyone a mirror.
Aggregate exposure. How much stone shows depends on grind depth and how the slab was finished originally, and it varies across one floor. Standing exclusions in the records state plainly that uniform aggregate exposure is not guaranteed. Agree the target on the mock-up, in writing, and judge the floor against that, not against a photograph of a different slab.
Limitations
Template rates come from completed-work estimating records and describe production on real jobs, imperfections included; they are planning figures, not guarantees for your slab. A test grind and a mock-up on your actual floor will tell you more about your schedule than any rate table, and a contractor unwilling to do either before committing to dates is guessing with your calendar.
Frequently asked questions
Can polishing be done at night or in phases while we operate?
Yes, and much of the work in the records is exactly that, retail and operating facilities polished in sections. Phasing costs production, so expect the calendar to stretch even though the man-hours barely change.
Why does a small floor take nearly as long per square foot as a big one?
Setup, protection, edge work, and cleanup are nearly fixed costs. Spread over 1,300 square feet they dominate; spread over 20,000 they fade, which is why template rates improve with size.
How long before we can use the floor?
Polished concrete has no coating cure to wait on. Once the final pass, joint filling, and cleanup are done and the area is handed back, it can generally go into service, which is one of its scheduling advantages over coatings.
Does a higher gloss level take longer?
Yes. Each step from 400 up to 800 or 1500 grit is another full pass over the floor, plus the burnish. Specifying the sheen is specifying schedule, so choose the gloss the space actually needs.
What should I confirm before signing off on a start date?
Power (480 volt or a real generator plan), a completed mock-up, flatness expectations, who moves what off the floor, and the phasing map. Those five items decide whether the date on the proposal survives contact with your building.
Planning a polish around your operation?
The schedule for a polished concrete job is decided by your slab, your power, and your phasing long before it is decided by a grinder. If you are planning polished concrete for a warehouse, store, or facility and want realistic dates, book a free consultation with a flooring consultant and walk through the floor’s condition, your power supply, and your access windows before anyone commits to a calendar.