Average response time: under 24 hours
Polished concrete in a supermarket is delivered to a live trading floor: shoppers, trolleys, jacks and restock traffic share the zones opened and handed back each night. Success rests less on final shine than on pre-pricing substrate decisions, segmentation around opening hours, and acceptance criteria agreed with the owner representative. This guide covers substrate judgement, load exposure, night sequencing, slip targets and handover.
Scope covers the sales floor, aisles, checkout lanes, produce and deli wet zones, back-of-house corridors and transition strips to tile or resin. Before mobilization, the PM confirms slab age, strength, coatings, joint layout and moisture; failing zones go into the tender assumptions, not site argument.
Record slab age, compressive strength from cores or certificates, and condition at three points per 100 m²: sound, cracked, coated or sealed. A slab under 28 days still gains strength and may release bleed water; grinding early opens air voids in uneven paste. Test RH in probes; stop above 75–80% RH, holding surface temperature between 10 and 30 °C through grinding and sealing. Profile to CSP 1–2 heavy aggregate, CSP 3–4 medium removal, or CSP 5–7 fine near mirror finish; hollow patches are cut out before polishing.
The floor mixes dynamic wheel loads and static point loads. Filled trolleys cross the same aisle strips thousands of times daily; jacks and stackers concentrate load on two or four wheels at racking ends and bays. Wheel traffic wears the paste, concentrated loads chip arrises, and racking aggravates existing cracks. Check joint spacing and saw-cut timing; isolation joints at columns, control joints every 5–6 m and construction joints must be honed and filled, since an unprotected arris spalls within months.
Most supermarket polishing runs in night shifts between close and first delivery, typically a 22:00 to 06:00 window. Split the floor into segments one crew can finish, clean and release in the available hours; a segment over 250–350 m² per grinder shift often leaves half-dried densifier or wet resin film at handover. Segment boundaries follow aisle layout so carts reroute around the closed zone. HEPA vacuums run on every grinder at segment edges; each segment is released after final clean, edge inspection and seal-coat walk-on time, with a signed punch note.
Run the sequence metal bond to resin in full-floor passes. Metal starts at 16 or 20 grit for heavy removal and open aggregate, then 30 and 40 grit to level ruts and transitions; skip a grit only after a straightedge check clears deeper scratches. Resin follows 100, 200, 400, 800, then 1500 or 3000 grit; scratches carried to 800 grit cannot be hidden by 1500 grit. Apply densifier when dust-free; dilute silicate 1:64 ≈ 15 ml/L first coat, 1:128 ≈ 8 ml/L second coat, keep wet-working 20–30 minutes, wait 4–12 hours between coats.
Produce, deli, butcher and washdown corridors see standing water, ice melt and runoff; the sales floor usually sees spills only. Specify slip targets by zone, not one floor-wide number. Dry PTV should read ≥36 on the polished sales floor; wet PTV typically runs 10–20 points below dry, and the wet zone must still clear DCOF ≥0.42 under wet testing. R10–R12 maps to wet areas: R10 dry aisles, R11 light spill zones, R12 where continuous washing or standing water is expected. Test slip at handover, recording readings per zone.
| Zone | Finish target | PTV dry | DCOF wet | Slip class |
|---|---|---|---|---|
| Sales aisles and checkout | 800–1500 grit, sealed | ≥36 | ≥0.42 | R10 |
| Produce runoff zone | 400–800 grit, sealed | ≥34 | ≥0.42 | R11 |
| Deli and butcher wet prep | 200–400 grit, dense seal | ≥32 | ≥0.42 | R11–R12 |
| Washdown and cleaning bay | Coarser textured finish, joint seal | ≥30 | ≥0.42 | R12 |
Appearance is judged under the store's own lighting, not the contractor's torch. Check gloss at 60° at fixed stations per 200 m²; adjacent zones may differ by up to 5 gloss units and stay acceptable, while a spread over 15 units between neighbours requires rework. Inspect under 300–500 lux oblique light for swirl marks, cloudiness, edge burn and residue; defects show best when light runs along the aisle. Match finish across transitions to tile, epoxy and coved skirtings: hone the edge straight and leave a clean joint line.
Run the final inspection with the owner representative against the tender schedule: gloss and slip readings, joint fill status, defect list and cleanliness, with readings kept in the binder. Frequent disputes are joint spalling, gloss mismatch, white densifier residue and wet-zone readings below target.
At handover, supply the as-built finish schedule, grit sequence, dilutions used, reading records and a maintenance note: dry sweep or dust-mop daily, clean spills within the shift, avoid harsh acids and high-pressure hot water on the sealed finish. Protect fresh seal coats for walk-on and heavy-traffic times, typically 24–72 hours before jack traffic resumes at full load. Plan recoating on traffic, not calendar: normal aisles refresh on a 3–5 year cycle, while checkout lanes and jack routes need a 2–3 year cycle.
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 quality management system are audited by SGS and Bureau Veritas. Products meet CE/RoHS requirements and every piece is 100% inspected before packing.
Verified Certificates
