Polished concrete in church and chapel halls serves the congregation on Sundays and special services, and sits beside stone, woodwork and copper fittings without disturbing the interior. This guide is for the contractor PM and owner representative agreeing substrate condition, work windows, interface closures, gloss judgment, wet-zone slip and acceptance points before entry.

Scope covers nave and side aisles, chapel, vestibule and narthex, baptismal font surround, corridors and transition strips to tile or wood. The PM records historic renovation or new build first: the two substrates demand different surveys, repair sequences and acceptance clauses, fixed in writing before work starts.

Polished concrete in church halls

Halls mix light daily footfall with high-event crowds and quiet periods. A sealed concrete layer adds no lifting film under chairs or procession traffic, and keeps dust down after densifier. Honed grades suit reverent interiors where mirror glare distracts: CSP 5–6 near-mirror suits vestibule and aisle centerline, chapels stay 400–800 grit honed. Per-zone target, gloss and slip limits are fixed in the tender schedule; no coating hides substrate defects.

Historic renovation versus new build

New build: the PM checks slab age, finish, curing, joints and moisture; slab cures 28–90 days, probe RH below 75% before densifier, joints over 3–4 mm photographed. Powdery areas are logged first: CSP 1–2 needs exposed-aggregate treatment, CSP 3–4 honed, CSP 5–7 near-mirror. Renovation adds old screeds, joist floors, coatings, wax and cracks; record rising damp 0.5–1.0 m up, cut mortar to sound concrete. Unrepairable zones are excluded with a dated note; readings are taken 2–3 times before densifier.

Work windows and silence rules around services

Work follows the service calendar, not one open floor. The timetable is agreed with the representative: Sunday services 8:00–12:00, masses, weddings, funerals, rehearsals and events are closed periods. Grinding and extraction run only in 3–4 hour blocks; noisy metal passes avoid services and visiting hours. Zones of 150–300 m² run one at a time with entry and barrier. Densifier areas stay closed overnight; traffic returns after 24–72 hours, equipment after 5–7 days; a weekly plan goes out 3–5 days ahead.

Stone, wood and copper floor closures

Church floors meet stone aisles and altar steps, wood pews, copper railings and narthex tile; the finish stops at a clean joint, never grinds into neighbors. Stone edges carry 3–5 mm tape, hand-ground to match; woodwork is masked 100–150 mm back; copper and brass are covered so slurry and densifier do not stain patina. Closure: expansion joints at transitions, thresholds leveled within 1–2 mm. Edges follow the same grit progression; copper spills are wiped within 10–15 minutes and rinsed, alkaline residue dulls patina.

Grit sequence and densification

Run metal to resin in overlapping passes. Metal starts at 16 or 20 grit to open laitance, then 30 and 40 grit; skip a grit only after marks clear. Resin follows 100, 200, 400, 800, then 1500 or 3000; scratches carried to 800 cannot be hidden by 1500. Lanes overlap 100–150 mm; each grit checks under 300–500 lux raking light. Densifier goes on dust-free: 1:64, about 15 ml/L, first coat; 1:128, about 8 ml/L, second, damp 20–40 minutes, RH below 75–80%, surface 10–30 ℃. Protection re-coats every 3–5 years, high-traffic zones every 2–3 years.

Gloss judgment under low light

Halls are judged under mixed light: dim nave lighting, daylight, candlelight, the PM's inspection lamp. Gloss measures at 60° on polished areas; adjacent zones differ by no more than 5 gloss units, a gap over 15 units requires rework. Readings are taken per 200 m² with zone, date, reading and sign-off; the written criterion, not impression, decides disputes. The final walk uses 300–500 lux raking light for scratches and cloud patches; candlelight judges appearance only. The table lists targets agreed before grinding.

Baptismal font wet zone

The font surround sees water, spills and drying feet, so it counts as a wet zone. Dry PTV ≥36; wet PTV runs 10–20 points below dry, DCOF ≥0.42 under water. Wet approaches and apron take R10–R12, rougher where it stays wet longest. Drainage slope is 1–2% toward channels or drains. Dripped wax hardens in 5–10 minutes, softens at 40–50 ℃ before plastic-blade scraping. Cleaners, bleach and wax removers test on a hidden patch; diluted agents 1:10 to 1:20 rinse off within 10–15 minutes, strong agents etch the sealer.

Acceptance sampling and handover checklist

The final walk runs with the owner representative, defects numbered before rework. Sampling points: aisle every 200 m², chapel center, font apron, narthex entry, two thresholds and joint lines. Disputes are uneven reflection, dull patches after densifier, wet-zone slip and edge bands; each checks against a written reading. Communication uses a named PM, weekly plan and photo log. Delivery supplies finish schedule, grit sequence, dilutions and maintenance note; the wear layer compacts in the first 6–12 months.

• Record substrate moisture, repair list and joint survey before grinding; attach readings to the acceptance file.
• Mark dull patches; check soft spots, pressure or fast densifier, then regrind resin stages to match gloss within 5 units.
• Check wet-zone complaints against dry and wet PTV and DCOF; agree honed finish or signage in writing before regrind.
• Inspect stone, wood and copper interfaces by hand grinder; record edge match, flag low spots at legs and bases.
• Hand over schedule, dilutions, cleaner guidance and re-coat cycle; each zone signed off, open items dated and assigned.