Polished concrete in a hotel lobby joins arrival, check-in, lounge circulation and back-of-house passage on one floor. This article covers substrate readiness, work windows, gloss-to-grip balance, protection and acceptance, for the contractor PM and owner's representative.

The lobby carries mixed use around the clock: trolleys, wet umbrellas, shoe debris, check-in traffic and service carts. Site limits below: dry PTV at least 36, wet DCOF at least 0.42, gloss at 60 degrees, inspection light 300 to 500 lux.

1. Scope and Site Conditions Before Lobby Polishing

The scope meeting splits the lobby into zones before grinding: apron and threshold, check-in frontage, lounge seating, lift and restaurant corridor, service passage. Finish is set zone by zone; record area, footfall and uninterruptible hours on the zoning map.

Confirm ventilation, slurry and machine storage, water and power access, and noise limits on guest floors. Keep slab temperature 10 to 30 degrees Celsius and RH below 75 to 80 percent; outside this envelope, grinding and curing behave unpredictably.

2. Substrate Moisture and Readiness at Handover

Moisture is the most common later dispute. Test at least four points per zone, including the apron and near external walls, recording internal RH and surface moisture. Above the limit, stop and agree a drying or membrane remedy in writing.

Document profile and defects on the walkthrough. CSP runs 1 to 2 for heavy aggregate, 3 to 4 for medium, 5 to 7 for near-mirror finish. Cracks, spalls, weak laitance and hollow joints are repaired before polishing; grinding a weak layer amplifies the defect.

3. Zoning, Work Windows and Night-Shift Organization

Most hotels cannot release the lobby for full-day work. Plan overnight windows, roughly 23:00 to 06:00, reserving day shifts for low-dust resin polishing. Each block includes set-up, running, slurry removal and cleanup; allow about 6 to 8 grinding hours, no extra passes.

Partition the active zone with barriers, covered walkways and signed diversions; protect adjacent stone, tile, desks and glass, and agree who cleans past the barrier. Sign off these checks before each night block:

• RH inside 75 to 80 percent; slab temperature 10 to 30 degrees Celsius, recorded per zone.
• Barriers, walkways and coverings in place; thresholds and adjacent finishes masked or boarded.
• Water, power and slurry disposal confirmed; roughly 100 to 200 liters of slurry held per block.
• Passes, grit sequence and finish agreed; cured areas marked off from traffic.

4. Grinding, Densifying and Polishing Pass Sequence

The sequence runs from coarse metal blocks to fine resin pads, densifier after a stable grind. Metal blocks use 16, 20, 30 and 40 grit; resin pads use 100, 200, 400, 800, 1500 and 3000 grit. Skip a grit only when no scratches remain; overlap one-third of head width.

Densifier ratios: 1:64, about 15 milliliters per liter, for the first coat; 1:128, about 8 milliliters per liter, for a lighter follow-up. Apply evenly, hold dwell time, remove slurry before it dries white. The table maps each pass, tooling and closing check.

5. Gloss Level and the High-Gloss to Anti-Slip Balance

Check-in and seating often want mirror reflection, but thresholds and wet-bar edges cannot match it, as wet polish slips. Gloss is read at 60 degrees; adjacent areas may differ up to 5 units, while a gap above 15 units usually needs rework. Set targets per zone and keep sample patches visible.

Slip is checked separately. Dry PTV at least 36; wet PTV drops 10 to 20 points, so rain entrances use finer hone or local anti-slip treatment, not mirror polish. DCOF at least 0.42 is the walking minimum; wet edges grade R10 to R12. A texture band blends in without a hard line.

6. Finishing Protection During Operating Hours

Protection starts before the first grind and ends after inspection. Mask furniture, plinths, brass, glass and planters; cover adjacent tile or marble so slurry cannot stain grout. Cured areas stay closed until cure time passes; seal access routes with removable sheets.

Touch-ups come from luggage or trolley wheels scratching the gloss band, or wet cleaning before cure ends. Keep a repair kit with matching pads and densifier; record each patch's zone for matching. Report protection failures the same day.

7. Acceptance Checks, Test Points and Common Disputes

Walk through under lobby lighting plus oblique light of 300 to 500 lux to reveal scratches, swirls, cloudiness and haze. Place grid test points per zone: entrance, mid-lounge, frontage, corridor center, near lifts, recording gloss, slip and visual check. Mark defects and agree the fix before sign-off.

Disputes fall into four groups. Gloss mismatch: mirror pictured against honed spec, fixed by visible samples. Rain slip: fixed by the texture band and wet DCOF limit. Crack patches: matched to surrounding CSP and grit. Haze blamed on cleaners: checked against the cure schedule. Settle on measurements.

8. Handover, Maintenance Follow-Up and Re-Coating Cycle

Hand over the zoning map with readings per point, dilution ratios, cure schedule and cleaning routine: daily dry mop, neutral-pH wet cleaning, no acid removers. Re-coat at 3 to 5 years generally, shortened to 2 to 3 years at high-traffic thresholds and aprons.

Close with a dated punch list, as-built repair record, and visits at 30 and 90 days for wear, gloss and dulling. Explain maintenance limits plainly. A lobby agreed on substrate, windows, zone finish and documented points opens with fewer disputes and a clearer plan.