+---
+title: Polished Concrete Flooring
+category: Architectural / Finishes
+toc_depth: 3
+description: >
+ When to use: Mechanically ground, honed, and polished concrete floor finishes produced in place by progressive bonded-abrasive diamond processing of a structural or topping concrete slab, including chemical densification and optional coloring with dye or stain. Covers true bonded-abrasive polishing (full grind-hone-polish to a measured gloss and clarity), grind-and-seal finishes, and burnished guard finishes; aggregate exposure selection (cement fines, fine aggregate, coarse aggregate), gloss and clarity levels, densifier chemistry, joint and crack filling, slip resistance, abrasion resistance, and the coordination required to protect a finished slab that is also the building's structural floor.
+ Not intended for: Fluid-applied resin floor finishes such as epoxy, polyurethane, MMA, and cementitious urethane, including grind-and-broadcast resinous systems (see [[sync/resinous-flooring]]); cementitious and epoxy-matrix terrazzo (see [[sync/terrazzo]]); natural stone and porcelain tile (see [[sync/natural-stone-tile]]); resilient sheet, tile, and plank coverings (see [[sync/resilient-flooring]]); the design, mix, placement, finishing, and curing of the concrete slab itself (see [[sync/cast-in-place-concrete]]); and exterior equipment pads and housekeeping pads (see [[sync/concrete-pads]]).
+---
+
+# Scope
+
+This standard governs the production of a polished concrete floor finish — a finished floor created by mechanically grinding, honing, and polishing the surface of an existing concrete slab with a progressive sequence of bonded diamond abrasives, hardening the surface with a chemical densifier, and optionally coloring it with a penetrating dye or chemical stain. The finished floor is not a covering applied over concrete; it is the concrete slab itself, refined into the final wearing and architectural surface. This makes polished concrete fundamentally different from every other floor finish in this library: there is no membrane, no tile, and no applied material between the traffic and the structural slab, so the appearance and performance of the finished floor are inseparable from the quality, flatness, hardness, and finishing history of the concrete that was placed long before the polishing contractor arrives.
+
+A polished concrete floor is specified where a durable, low-maintenance, light-reflective, and dust-free monolithic floor is wanted without the cost and recurring maintenance of an applied covering: retail, warehouse and distribution, manufacturing, institutional and educational buildings, lobbies, and increasingly residential and hospitality interiors. Its appeal is that the finish is the structure, so there is nothing to delaminate, no covering to replace, and no recurring stripping and recoating; properly densified and maintained, the surface resists abrasion and tire traffic and reflects light, reducing lighting load. Its risk is that the result is largely determined by conditions the polishing contractor does not control — slab flatness, the cement-paste-to-aggregate relationship at the surface, the presence of curing compounds, and above all whether the slab is hard enough to take a polish — and a defect in the slab becomes a permanent, visible defect in the finished floor that cannot be covered.
+
+Three distinct finish processes are covered by this standard and shall not be confused, because they differ in cost, durability, and appearance and are frequently substituted for one another to the Owner's detriment. A true bonded-abrasive polished finish is produced entirely by progressive diamond grinding, honing, and polishing of the densified slab, so the gloss and clarity come from the refined concrete surface itself; this is the most durable and the most expensive process and is the only one that the ACI specification recognizes as polished concrete. A grind-and-seal finish grinds the slab to the wanted aggregate exposure and then achieves sheen with a topical film-forming sealer rather than by mechanical polishing; it is faster and less costly but introduces an applied film that wears, scratches, and must eventually be reapplied — it is a coated floor, not a polished one. A burnished guard finish applies a topical guard or protective treatment over a lightly processed or densified slab and buffs it to a sheen; it is the least durable and is appropriate only for light-traffic or budget applications. The process shall be selected and stated explicitly, because the words polished, sealed, and guarded describe three different floors at three different price points.
+
+The two decisions that define the look of a polished floor are the aggregate exposure and the gloss and clarity level, and they are independent of one another. Aggregate exposure is how deeply the surface is ground — from a cream finish that grinds away almost nothing and exposes only cement paste, through a salt-and-pepper finish that exposes the fine sand, to a full aggregate finish that grinds down to expose the large stone — and it is set early in the process and is irreversible once ground. Gloss and clarity is how finely the exposed surface is then polished, from a low matte sheen to a high mirror reflection, and is set by how far up the grit sequence the polishing is carried. The Owner shall select both, because a low-gloss floor with full aggregate exposure and a high-gloss floor with a cream finish are radically different in appearance and cost.
+
+Coordinate the slab with [[sync/cast-in-place-concrete]] before it is placed: a slab intended to be polished must be designed, placed, finished, and cured for polishing, which is a different and more demanding requirement than an ordinary slab. It needs adequate and consistent surface hardness, a controlled and consistent aggregate distribution near the surface, tight flatness tolerances, hard steel troweling without overworking or trowel burning, and a curing method compatible with later grinding — preferably wet or sheet curing or a dissipating cure, never a permanent membrane-forming compound that the polisher must grind off. Coordinate transitions and elevations with [[sync/resinous-flooring]], [[sync/natural-stone-tile]], and [[sync/resilient-flooring]], and coordinate the joint-filling scope and timing carefully, because joint filling, polishing, and the slab's drying shrinkage interact.
+
+# Referenced Standards
+
+All materials, processing, testing, and acceptance shall comply with the latest edition adopted by the Authority Having Jurisdiction for each of the following standards. Where the contract documents, a referenced standard, or a product manufacturer's written instructions impose a more stringent requirement than the minimum of any other standard, the more stringent requirement governs unless the Architect of Record directs otherwise in writing. Polishing is a field process whose result is verified by measurement against published appearance and performance criteria, so the contract shall state which standard's appearance scale and acceptance method govern.
+
+| Standard | Title |
+|----------|-------|
+| ACI 310.1-20 | Specification for Polished Concrete Slab Finishes |
+| ACI 310R-19 | Guide to Decorative Concrete |
+| ASTM C779 / C779M | Standard Test Method for Abrasion Resistance of Horizontal Concrete Surfaces |
+| ASTM C1028 | Standard Test Method for Static Coefficient of Friction of Ceramic Tile and Other Like Surfaces by the Horizontal Dynamometer Pull-Meter Method (withdrawn; referenced for legacy SCOF requirements) |
+| ANSI A326.3 | Test Method for Measuring Dynamic Coefficient of Friction of Hard Surface Flooring Materials |
+| ASTM E430 | Standard Test Methods for Measurement of Gloss of High-Gloss Surfaces by Abridged Goniophotometry (distinctness-of-image and reflection haze) |
+| ASTM D523 | Standard Test Method for Specular Gloss |
+| ASTM D5767 | Standard Test Methods for Instrumental Measurement of Distinctness-of-Image (DOI) Gloss of Coated Surfaces |
+| ASTM E1155 | Standard Test Method for Determining FF Floor Flatness and FL Floor Levelness Numbers |
+| ASTM F710 | Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring (substrate moisture and pH procedures) |
+| ASTM F1869 | Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride |
+| ASTM F2170 | Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes |
+| ASTM C309 | Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete |
+| ASTM C1315 | Standard Specification for Liquid Membrane-Forming Compounds Having Special Properties for Curing and Sealing Concrete |
+| IBC | International Building Code (current edition adopted by jurisdiction) |
+
+ACI 310.1-20 is the consensus specification, written jointly by ACI and the American Society of Concrete Contractors (ASCC) Concrete Polishing Council, that defines polished concrete as a bonded-abrasive process and establishes the aggregate exposure classes, the gloss levels measured by distinctness-of-image, and the acceptance and protection requirements this standard adopts. ASTM E430 and ASTM D5767 are the instrumental methods behind the distinctness-of-image (DOI) and reflection-haze measurements that the modern appearance scale uses in place of single-angle specular gloss, because DOI and haze describe the sharpness and clarity of the reflected image as the eye perceives it, where a 60-degree gloss reading alone can be manipulated and does not correlate well with perceived clarity. ASTM C779 is the abrasion-resistance method for horizontal concrete surfaces, and ANSI A326.3 is the dynamic-coefficient-of-friction method that has superseded the withdrawn ASTM C1028 static method for slip-resistance acceptance.
+
+# Submittals
+
+## Action Submittals
+
+The Contractor shall submit the following for the Architect's review before processing begins. Because the finished floor is the slab itself and cannot be replaced if processed wrong, the slab assessment and the mock-up are the most consequential submittals in this standard and shall be reviewed and accepted before any production grinding starts.
+
+- Product data for the densifier (identifying the silicate or colloidal-silica chemistry), any dye or stain, any guard or topical sealer, the joint and crack filler, and the patching and repair materials, with each manufacturer's written application instructions
+- A written processing plan stating the finish process (bonded-abrasive polish, grind-and-seal, or burnished guard), the target aggregate exposure class, the target gloss and clarity level, the planned diamond grit sequence and bond types, the densifier application step in the sequence, and the planned joint-filling sequence and timing
+- A slab assessment report for the actual slab to be polished, documenting measured surface hardness, observed surface profile and aggregate distribution, the presence of any curing compound or surface treatment, the existing flatness, and existing cracks, joints, surface defects, and embedded items, with the Contractor's identification of any condition that will limit the achievable finish
+- Substrate moisture test reports where a guard, dye, stain, or sealer is to be applied, conducted per ASTM F2170 (in-situ relative humidity) and, where used, ASTM F1869, with the surface pH per the ASTM F710 procedure
+- Samples or a referenced mock-up establishing each aggregate exposure class and gloss level proposed, in the project's color where dye or stain is used
+- The cleaning and maintenance program for the finished floor, identifying approved pH-neutral cleaning agents and the guard reapplication interval where applicable
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Product data — densifier, dye/stain, guard/sealer, joint filler, patch/repair materials"
+ - "Written processing plan (process, exposure, gloss, grit sequence, densifier step, joint sequence)"
+ - "Slab assessment report (hardness, profile, curing compound, flatness, defects)"
+ - "Substrate moisture and pH reports (F2170 / F1869 / F710) — where guard/dye/stain/sealer used"
+ - "Samples or referenced mock-up — each exposure class and gloss level"
+ - "Cleaning and maintenance program"
+default: "Slab assessment report (hardness, profile, curing compound, flatness, defects)"
+```
+
+## Closeout Submittals
+
+- Record of the as-built finish process, final aggregate exposure class, and measured gloss/clarity (DOI and haze) by area
+- Record of the densifier product and application rate, the joint and crack filler used, and any dye, stain, or guard applied
+- Manufacturer warranties for the densifier, guard, and joint filler, executed in the Owner's name where offered
+- The cleaning and maintenance program and any guard reapplication schedule, transmitted to the Owner
+
+# Quality Assurance
+
+## Installer Qualifications
+
+Polishing shall be performed by a contractor with documented experience producing bonded-abrasive polished concrete of the specified process, aggregate exposure, and gloss level on projects of comparable size, and trained in the chosen densifier and tooling systems. Polishing is a one-way process: each grinding pass removes material that cannot be put back, and a contractor who exposes too much aggregate, burns the surface with worn diamonds, or applies densifier at the wrong step in the sequence produces a permanent, visible defect in the Owner's structural floor. The Contractor shall not assign polishing to general labor or to crews experienced only in surface preparation grinding for coatings, because preparing a slab for a coating and polishing a slab to a measured clarity are different skills.
+
+```datasheet
+label: Installer Qualification
+type: radio
+options:
+ - "Experienced polished-concrete contractor (documented projects of comparable process, exposure, and gloss)"
+ - "Manufacturer-trained applicator for the specified densifier and tooling system"
+default: "Experienced polished-concrete contractor (documented projects of comparable process, exposure, and gloss)"
+```
+
+## Mock-Up
+
+```datasheet
+label: Mock-Up Required
+type: radio
+options:
+ - "Yes — process a representative area to the full grit sequence, including a joint and a typical defect repair"
+ - "No"
+default: "Yes — process a representative area to the full grit sequence, including a joint and a typical defect repair"
+```
+
+Where a mock-up is required, the Contractor shall process a representative in-place area of the actual slab — not a separate sample panel — to the full specified grit sequence, densifier application, and any dye, stain, or guard, including a filled joint and a representative patch or defect repair. Polished concrete cannot be represented by an off-site sample because the result depends entirely on this slab's hardness and aggregate, so the mock-up shall be cut from the project slab in an area that will either remain in the work or be acceptable to sacrifice. The mock-up establishes the accepted aggregate exposure, the accepted variation in exposure across the area, the gloss and clarity, the color, the joint-fill appearance, and the repair appearance, and shall remain available for comparison throughout the work. The mock-up also serves to confirm that this slab can in fact reach the specified finish before the entire floor is committed.
+
+## Pre-Processing Conference
+
+Before processing begins, the Contractor shall hold a conference with the Architect, the polishing contractor, and the concrete subcontractor to review the slab assessment, the curing method that was actually used, the flatness, the locations of joints and embedded items, the processing plan and grit sequence, the densifier step, the joint-filling sequence and timing, the protection plan, and the sequencing relative to other trades. The single most important outcome of this conference is agreement on whether the slab as placed and cured can reach the specified finish, and what the remedy is if it cannot — because the slab is already in place and its defects are now permanent.
+
+## Polishing Must Be Among the Last Trades
+
+The finished polished floor shall be among the last work performed in a space, and the slab shall not be polished to its final gloss until overhead and adjacent trades that could stain, scratch, gouge, or contaminate the floor are complete, or until a robust protection regime is in place. Unlike a covering installed at the end over a protected slab, a polished floor is the slab, so it is exposed to every trade from the day it is placed; pipe-cutting oil, paint, joint compound, fasteners dropped from lifts, and rebar rust stains all etch or embed into bare concrete and into a polished surface. The Contractor and the GC shall sequence the work so that final polishing and any dye, stain, or guard occur after the dirty trades are finished, and shall protect the slab continuously from placement through turnover.
+
+# Substrate and Environmental Conditions
+
+## Slab Suitability and Surface Hardness
+
+The slab shall be sound, sufficiently hard, and consistent enough in surface hardness to take and hold a polish, and the Contractor shall confirm suitability by the slab assessment before processing. A soft slab — one with a weak, dusty, or inconsistent surface, common where the concrete was over-watered, finished too early over bleed water, or cured poorly — will not refine to a clear polish: the diamonds tear the soft paste rather than cutting it, the surface will not close up, and the floor remains dull and dusty no matter how far the grit sequence is carried. Where the assessment finds a soft or inconsistent slab, the densifier shall be applied earlier and in additional applications to build surface hardness before final polishing, and the Architect shall be notified that the achievable gloss may be limited; this additional densification is extra work that was caused by the concrete, not the polishing, and the responsibility for the added cost shall be resolved rather than imposed silently on the polishing contractor.
+
+## Curing Compound and Surface Treatments
+
+The slab shall be free of any membrane-forming curing compound, sealer, hardener, or surface treatment that interferes with diamond cutting and densifier penetration, or such treatments shall be ground off as the first processing step. A permanent membrane-forming curing compound per ASTM C309 or a cure-and-seal per ASTM C1315 left on a slab intended for polishing must be removed by grinding before the densifier can penetrate, adding cost and risk; a slab intended for polishing should therefore be cured by water, wet sheet, or a dissipating-resin compound rather than a permanent membrane. The Contractor shall verify which curing method was used and shall account for compound removal in the processing plan.
+
+## Slab Flatness
+
+```datasheet
+label: Floor Flatness / Levelness (ASTM E1155) — coordinate with cast-in-place concrete
+type: radio
+drawing_ref: true
+options:
+ - "Standard — FF 35 / FL 25 (typical interior polished floor)"
+ - "Flat — FF 50 / FL 30 (high-gloss, long sightlines, retail)"
+ - "Very flat — FF 60 / FL 40 (premium high-clarity finish)"
+default: "Standard — FF 35 / FL 25 (typical interior polished floor)"
+```
+
+The slab flatness measured per ASTM E1155 shall meet the FF/FL numbers specified, and the flatness requirement shall be coordinated with [[sync/cast-in-place-concrete]] before the slab is placed, because flatness is established at placement and cannot be improved by polishing. Flatness matters more for a polished floor than for a covered one because the polish creates a reflective surface: under bright lighting and long sightlines, every dip and wave in an out-of-flat slab is revealed by the reflection and by uneven aggregate exposure, since grinding a wavy slab to a flat plane exposes more aggregate in the high spots than the low spots. A high-gloss floor with long sightlines, such as a retail showroom, requires a flatter slab than a matte warehouse floor, and the FF/FL target shall be matched to the gloss and the lighting rather than defaulted.
+
+## Moisture Conditions for Coloring and Guard Treatments
+
+Where a dye, stain, guard, or topical sealer is to be applied, the slab moisture condition shall be verified by test before application, because a topical film over a wet slab can blush, discolor, or peel even though the underlying densified polish is unaffected by moisture. In-situ relative humidity shall be measured per ASTM F2170 and the surface pH per the ASTM F710 procedure, against the limits of the dye, stain, guard, or sealer manufacturer. A bonded-abrasive polished and densified floor with no topical film is not moisture-sensitive in the way a coating is, so where no film-forming product is applied, moisture testing is informational rather than a hold point — but any topical guard or sealer reintroduces the moisture-sensitivity of an applied film and the manufacturer's moisture limit then governs.
+
+```datasheet
+label: Maximum Slab Internal Relative Humidity for Topical Guard / Sealer (ASTM F2170)
+type: range
+unit: "% RH"
+options:
+ min: 75
+ max: 90
+ step: 5
+ setpoints: [75, 80, 85, 90]
+default: 85
+```
+
+# Polishing System
+
+## Finish Process
+
+```datasheet
+label: Finish Process
+type: select
+drawing_ref: true
+options:
+ - "Bonded-abrasive polished concrete — full grind-hone-polish, gloss from refined concrete (ACI 310.1)"
+ - "Grind-and-seal — ground to exposure, sheen from topical film-forming sealer"
+ - "Burnished guard finish — densified/lightly processed, topical guard buffed to sheen"
+default: "Bonded-abrasive polished concrete — full grind-hone-polish, gloss from refined concrete (ACI 310.1)"
+```
+
+The finish process shall be selected for the durability, appearance, and budget required. A bonded-abrasive polished concrete finish carries the grind-hone-polish sequence through fine resin-bond diamonds so that the gloss and clarity are mechanical properties of the refined, densified concrete itself; it is the most durable finish, the only one ACI 310.1 recognizes as polished concrete, and the only one whose sheen does not wear off because there is no film to wear. A grind-and-seal finish grinds the slab to the wanted aggregate exposure and then achieves sheen with a topical film-forming sealer rather than by mechanical polishing — faster and cheaper, but the sheen lives in an applied film that scratches, wears in traffic lanes, and must be stripped and reapplied periodically, and it is properly understood as a coated floor. A burnished guard finish applies a topical guard over a densified or lightly processed slab and buffs it; it is the least durable and is suited only to light traffic or tight budgets. Each step down trades initial cost for recurring maintenance and shorter life.
+
+## Aggregate Exposure Class
+
+```datasheet
+label: Aggregate Exposure Class (ACI 310.1)
+type: select
+drawing_ref: true
+options:
+ - "Class A — cement fines (cream): grinds away minimal surface, exposes paste, little or no sand"
+ - "Class B — fine aggregate (salt-and-pepper): exposes fine sand uniformly"
+ - "Class C — coarse aggregate: grinds down to expose large aggregate (terrazzo-like)"
+default: "Class B — fine aggregate (salt-and-pepper): exposes fine sand uniformly"
+```
+
+The aggregate exposure class shall be selected and is irreversible once ground. A Class A cement-fines (cream) finish removes almost nothing from the surface and exposes cement paste with little or no sand, giving the most uniform, monolithic look and the least visual variation; it depends entirely on a hard, consistent surface paste and shows surface defects and trowel marks most readily. A Class B fine-aggregate (salt-and-pepper) finish grinds slightly deeper to expose the fine sand uniformly across the floor and is the most common and most forgiving selection because it masks minor surface variation while keeping a controlled, even appearance. A Class C coarse-aggregate finish grinds down far enough to expose the large stone in a terrazzo-like pattern; it is the most dramatic and is highly dependent on a consistent slab — the depth of grind needed to reach the large aggregate everywhere makes any variation in the slab's surface plane show as uneven exposure, so it demands a flatter, more uniform slab and accepts more visual variation. Because exposure is determined by how much surface is ground away, the exposure class is coupled to the slab flatness: a uniform Class C exposure is achievable only on a flat, consistently placed slab.
+
+## Aggregate Exposure Uniformity
+
+The aggregate exposure shall be reasonably uniform across each continuous floor area, judged against the accepted mock-up over the overall area of the floor rather than at any single point. Some natural variation in exposure is inherent because concrete is not perfectly homogeneous and a ground slab plane intersects a non-flat surface at varying depths; the acceptance criterion is the overall appearance of the area, not point-by-point uniformity. Inconsistent aggregate exposure — patches of cream next to patches of full aggregate within an area intended to be uniform — is one of the most common appearance complaints and usually traces to an out-of-flat slab or inconsistent finishing, conditions established before polishing began.
+
+## Gloss and Clarity Level
+
+```datasheet
+label: Gloss / Clarity Level (ACI 310.1, measured by distinctness-of-image)
+type: select
+drawing_ref: true
+options:
+ - "Level 1 — flat / matte (low reflection, no clear image)"
+ - "Level 2 — satin / low sheen (slight reflection)"
+ - "Level 3 — semi-polished / medium gloss (clear but soft reflection)"
+ - "Level 4 — highly polished / high gloss (sharp, mirror-like reflection)"
+default: "Level 3 — semi-polished / medium gloss (clear but soft reflection)"
+```
+
+The gloss and clarity level shall be selected independently of the aggregate exposure and is achieved by how far the polishing is carried up the diamond grit sequence. Level 1 is a flat, matte finish reflecting little light with no discernible image, produced by stopping the sequence at a coarse resin grit; Level 2 is a satin or low sheen; Level 3 is a semi-polished medium gloss with a clear but soft reflection, the most common commercial selection balancing appearance against the cost of additional polishing passes; Level 4 is a highly polished, high-gloss finish with a sharp, mirror-like reflection, carried to the finest resin grits or burnished. Higher gloss requires more passes and more refinement, costs more, reveals more about the flatness and defects of the slab, and can produce glare under bright lighting; the level shall be matched to the use and the lighting rather than maximized. The level shall be verified by distinctness-of-image (DOI) and reflection-haze measurement rather than by single-angle specular gloss, because DOI and haze correspond to the perceived sharpness of the reflected image while a 60-degree gloss reading can be raised by a topical film without producing a truly clear, polished surface.
+
+## Densifier Chemistry
+
+```datasheet
+label: Densifier Chemistry
+type: radio
+options:
+ - "Lithium silicate — low residue, fast reaction, broad compatibility (typical default)"
+ - "Sodium silicate — economical, suited to softer, more porous slabs (higher residue)"
+ - "Potassium silicate — silicate alternative for specific slab conditions"
+ - "Colloidal silica — finest particle, lowest residue, can be burnished to high sheen (best on harder slabs)"
+default: "Lithium silicate — low residue, fast reaction, broad compatibility (typical default)"
+```
+
+A chemical densifier shall be applied to react with the free lime in the cement paste and deposit silica in the surface pore structure, hardening and tightening the surface so it takes and holds a polish and resists abrasion and dusting. All silicate and colloidal-silica densifiers deliver reactive silica into the paste and differ chiefly in the alkali used to keep the silica in solution, the particle size, and the residue left behind. Lithium silicate reacts quickly, leaves little residue, and is broadly compatible across slab conditions, which makes it the common default. Sodium silicate is economical and works on softer, more porous slabs but leaves more glassy residue that must be removed and is more labor-intensive to clean. Potassium silicate is a silicate alternative selected for particular conditions. Colloidal silica has the smallest particle size and the highest silica purity, leaves essentially no residue, penetrates the finest pores, and can be built up and burnished to a high sheen, but it performs best on harder, lower-free-lime slabs and is less effective on weak, low-strength concrete. The Contractor shall select the densifier for the measured slab condition; a weak slab is hardened more reliably by an alkaline silicate that floods and fills, while a strong slab with pozzolanic admixtures is better served by colloidal silica.
+
+## Densifier Application Timing
+
+The densifier shall be applied at the step in the grit sequence the densifier manufacturer specifies, commonly after an intermediate resin grit when the surface is partially closed, and additional applications shall be made where the slab assessment found a soft surface needing more hardness before final polishing. Applying densifier too early on an open surface wastes material that soaks in without building surface hardness, while applying it too late over a closed surface leaves it sitting on top as residue; the correct step is part of the processing plan. On a soft slab, early and repeated densification is the primary tool for building enough surface hardness to reach the specified gloss, and the additional applications shall be planned and priced rather than discovered mid-job.
+
+## Coloring — Dye or Stain
+
+```datasheet
+label: Coloring
+type: select
+drawing_ref: true
+options:
+ - "None — natural concrete color"
+ - "Penetrating dye — uniform, broad color range, interior only"
+ - "Reactive (acid) chemical stain — variegated, mottled, permanent mineral color"
+default: "None — natural concrete color"
+```
+
+Where the floor is to be colored, the coloring method shall be selected for the look and exposure. A penetrating dye carries fine pigment into the polished surface and gives a uniform, repeatable color across a broad palette, applied during the polishing sequence; dyes are the common interior choice but most are not UV-stable and are not for areas in direct sunlight. A reactive (acid) chemical stain reacts with the lime in the concrete to deposit a permanent, variegated, mottled mineral color with a natural translucent character; it offers a limited earth-tone palette and a less predictable, more artistic result that varies with the concrete. Coloring shall be selected from the accepted mock-up, because the color a dye or stain produces depends on the specific concrete and the aggregate exposure beneath it. The color selection shall be as indicated in the [[drawing: finish schedule]].
+
+## Guard / Protective Treatment
+
+```datasheet
+label: Guard / Protective Treatment
+type: radio
+options:
+ - "None — densified bonded-abrasive polish only"
+ - "Topical guard / stain-protection treatment, buffed in (recommended for retail/food service)"
+default: "None — densified bonded-abrasive polish only"
+```
+
+A topical guard or stain-protection treatment may be applied over the finished polish and buffed in to improve initial stain resistance and sheen, particularly in retail, food-service, and high-spill areas where the bare densified surface, though dense, is not impervious to acidic spills that can etch it. A guard is a sacrificial maintenance film, not a permanent part of the floor: it wears in traffic lanes and is periodically reapplied as part of the maintenance program, and it should not be confused with the grind-and-seal process, in which the sheen itself comes from a film. Where the floor is a true bonded-abrasive polish, the guard is optional protection over an already-finished surface; where stain risk is high, it is recommended.
+
+# Joint and Crack Treatment
+
+## Joint Filler Material
+
+```datasheet
+label: Joint and Crack Filler
+type: radio
+options:
+ - "Semi-rigid polyurea, Shore A 80 or harder, color as selected"
+ - "Semi-rigid epoxy, Shore A 80 or harder, color as selected"
+default: "Semi-rigid polyurea, Shore A 80 or harder, color as selected"
+```
+
+Sawn contraction (control) joints and static cracks in the slab shall be filled flush with a semi-rigid joint filler of Shore A 80 hardness or harder so the filler supports the joint edges against traffic and spalling while the polishing diamonds can pass over it without tearing it out. A semi-rigid polyurea or epoxy filler is required rather than a soft elastomeric sealant, because a soft sealant smears under the diamonds and does not protect the joint shoulders from chipping under hard-wheeled traffic; the semi-rigid filler bonds to the joint walls, supports the edges, and grinds cleanly. The filler color shall be selected from the accepted mock-up to either match or deliberately contrast the floor. Isolation and expansion joints that must accommodate building movement shall not be rigidly filled and shall be honored as moving joints; only contraction joints and non-moving cracks receive the semi-rigid filler.
+
+## Joint-Filling Sequence and Timing
+
+Contraction joints shall be filled as late in the construction schedule as the polishing sequence permits, after the slab has undergone the majority of its drying shrinkage, so the joints have opened to near their final width before they are filled. A joint filled too early, before the slab has shrunk, will separate from one or both joint walls as the slab continues to shrink, leaving a gap that collects debris and no longer supports the edges. Where joints must be filled early to allow traffic, the Contractor shall plan to re-fill or repair separations before final polishing. The filling sequence relative to the grit steps shall follow the processing plan so that filled joints are ground flush during polishing.
+
+# Execution and Processing
+
+## Slab Acceptance Before Processing
+
+The Contractor shall not begin production processing until the slab assessment is complete and accepted, any curing compound or surface treatment has been removed or accounted for, defects and embedded items are identified, the mock-up is accepted, and the protection and sequencing plan is in place. Acceptance of the slab is the Contractor's responsibility to the extent that conditions are observable; conditions hidden within the slab — inconsistent hardness, buried defects — that limit the achievable finish shall be raised as soon as they are discovered during processing, because the floor cannot be replaced.
+
+## Grinding — Coarse Cut and Aggregate Exposure
+
+Processing shall begin with coarse metal-bond diamond segments to flatten the surface, remove any coating, and grind to the specified aggregate exposure class, typically starting in the range of 30 to 40 grit and stepping up through successively finer metal-bond grits. The coarse metal-bond stage is where the aggregate exposure is set and is irreversible, so the depth of cut shall be controlled to reach the specified class uniformly without over-grinding. The diamond bond hardness shall be matched inversely to the concrete hardness — a harder bond for soft concrete and a softer bond for hard concrete — so the diamonds cut rather than glaze or wear prematurely. Each grit shall fully remove the scratch pattern of the previous grit before advancing, because a scratch left by a coarse grit cannot be removed by a finer one and will show in the finished floor.
+
+## Honing — Transition Stage
+
+After the coarse metal-bond cut, the surface shall be honed through transitional (hybrid) and finer abrasives that begin to close the surface and remove the deeper scratch pattern, refining the matte ground surface toward a honed surface ready for polishing. The honing stage bridges the aggressive metal-bond grinding and the fine resin-bond polishing; skipping or rushing it leaves a coarse scratch pattern that no amount of fine polishing will erase, producing a hazy floor that will not reach clarity.
+
+## Densification Step
+
+The densifier shall be applied at the planned step in the sequence, allowed to react per the manufacturer's instructions, and any residue removed before processing continues. The densification step hardens the surface so the subsequent resin-bond polishing can refine it to a clear, dust-free finish; on a soft slab, additional applications shall be made as planned to build the hardness the final gloss requires.
+
+## Polishing — Resin-Bond Refinement to Specified Gloss
+
+The honed, densified surface shall be polished with progressively finer resin-bond diamonds — through grits such as 100, 200, 400, 800, 1500, and 3000 — until the specified gloss and clarity level is reached, with each grit fully removing the prior scratch pattern. Stopping at a coarser resin grit yields a lower gloss level; carrying the sequence to the finest resin grits, or burnishing, yields the highest gloss. The polishing stage is where the gloss level is produced, and the floor shall not be accepted until the measured clarity meets the specified level uniformly across each area.
+
+## Avoiding Trowel Burn and Surface Defects in Processing
+
+The Contractor shall keep diamonds sharp and the bond matched to the slab to avoid burnishing or burning the surface during grinding, and shall not attempt to mask an inadequate cut with a topical film. Trowel burn — a hard, dark, glazed surface produced when the original concrete was over-troweled — and worn or wrong-bond diamonds both produce a surface that will not refine evenly, leaving dark, dense patches that polish differently from the surrounding floor. Where trowel burn or other surface defects from the original finishing are found, they shall be raised at the pre-processing conference or as soon as discovered, because they are slab conditions, permanent, and not curable by polishing alone.
+
+# Testing and Acceptance
+
+## Gloss and Clarity Verification
+
+```datasheet
+label: Gloss / Clarity Verification Method
+type: radio
+options:
+ - "Distinctness-of-image (DOI) and haze per ASTM E430 / D5767, compared to specified level"
+ - "Visual comparison to accepted mock-up only"
+default: "Distinctness-of-image (DOI) and haze per ASTM E430 / D5767, compared to specified level"
+```
+
+The finished gloss and clarity shall be verified against the specified level, preferably by instrumental distinctness-of-image and haze measurement per ASTM E430 and ASTM D5767 using a concrete clarity meter, with readings taken across each area and compared to the level's acceptance values. Instrumental DOI and haze are preferred over single-angle specular gloss because they quantify the sharpness of the reflected image as perceived, and because a specular gloss reading can be inflated by a topical film that does not represent a truly polished surface; where instrumental verification is not specified, visual comparison to the accepted mock-up under the project lighting governs. Readings shall be taken under representative lighting because gloss perception depends on the light source.
+
+## Abrasion Resistance
+
+```datasheet
+label: Abrasion Resistance Verification (ASTM C779)
+type: radio
+options:
+ - "Not required — densification and finish process deemed to provide abrasion resistance"
+ - "Required — ASTM C779 procedure at frequency in contract documents"
+default: "Not required — densification and finish process deemed to provide abrasion resistance"
+```
+
+Where abrasion resistance is to be verified, the finished, densified surface shall be tested per ASTM C779 at the locations and frequency the contract documents establish. Densification and full polishing develop a hard, abrasion-resistant wearing surface, and for most projects the finish process and densifier application are deemed to provide the required abrasion resistance without separate testing; explicit ASTM C779 verification is warranted on heavy industrial floors where abrasion performance is a contractual requirement.
+
+## Slip Resistance
+
+```datasheet
+label: Slip-Resistance Requirement (ANSI A326.3 dynamic coefficient of friction)
+type: radio
+drawing_ref: true
+options:
+ - "DCOF not less than 0.42 (level interior, walked dry)"
+ - "DCOF not less than 0.42 wet, plus traction treatment where wet exposure is expected"
+default: "DCOF not less than 0.42 (level interior, walked dry)"
+```
+
+The finished floor shall provide a dynamic coefficient of friction of not less than 0.42 measured per ANSI A326.3 for level interior areas walked on dry. A highly polished concrete floor is smooth and can become slippery when wet, so in areas with foreseeable water, grease, or spills — entries, food-service areas, and around fixtures — a traction-enhancing treatment shall be applied or a lower gloss specified, because a high gloss and high wet-slip resistance are in tension. The ANSI A326.3 dynamic method has superseded the withdrawn ASTM C1028 static method for slip-resistance acceptance; where a project still invokes a static coefficient of friction, that legacy requirement shall be stated explicitly. Slip resistance shall be evaluated for each area against its actual wet exposure rather than assumed from the dry reading.
+
+## Moisture Verification for Topical Treatments
+
+Where a dye, stain, guard, or topical sealer is applied, the documented ASTM F2170 relative humidity and ASTM F710 pH results shall confirm the slab is within the product manufacturer's limits before the treatment is applied. A bonded-abrasive polish with no topical film does not require moisture acceptance, but any film-forming treatment reintroduces the moisture sensitivity of an applied coating and the manufacturer's limit becomes a hold point.
+
+## Visual Inspection
+
+After final processing, the floor shall be inspected against the accepted mock-up for uniformity of aggregate exposure, gloss and clarity, color where colored, joint-fill appearance, freedom from coarse scratch patterns, swirl marks, trowel-burn patches, and processing damage, under the project's permanent or equivalent lighting. Because the reflective surface reveals defects that a matte surface conceals, inspection shall be made under the lighting and from the sightlines the floor will be viewed in service. Defects arising from the polishing process — scratch patterns, swirl, uneven gloss — are the Contractor's responsibility to correct; defects arising from the slab — inconsistent exposure from out-of-flat concrete, trowel burn, surface defects — shall be evaluated against the accepted mock-up and the documented slab assessment.
+
+# Cleaning, Maintenance, and Protection
+
+## Final Cleaning
+
+At completion the floor shall be cleaned of all processing slurry, dust, and construction soil with a pH-neutral cleaner and left clean and dust-free for turnover. Polishing produces a fine slurry that shall be fully removed, because dried slurry and densifier residue left on the surface dull the finish and are difficult to remove later.
+
+## Maintenance Program
+
+The Contractor shall furnish the Owner with a written maintenance program specifying routine cleaning with pH-neutral cleaners only, prompt removal of acidic and staining spills, and, where a guard was applied, the buffing and guard-reapplication interval. Acidic cleaners and spills etch the densified surface and dull the polish, and the most common cause of a polished floor losing its appearance in service is cleaning with the wrong chemicals; the maintenance program is therefore part of preserving the finish, not an afterthought. A bonded-abrasive polished floor is maintained by cleaning and periodic burnishing rather than by stripping and recoating, which is its principal maintenance advantage over a coated or grind-and-seal floor.
+
+## Protection Until Turnover
+
+The finished floor shall be protected from staining, scratching, gouging, and chemical exposure from the time it is finished until turnover, using a breathable protective covering where other work continues in the space. Because the polished floor is the structural slab and cannot be replaced, protection is not optional; covers that trap moisture against the slab shall not be used where a topical guard or sealer was applied, and adhesive tapes that stain or pull the surface shall not be applied directly to the finished floor.
+
+# Warranty
+
+```datasheet
+label: Workmanship Warranty Period
+type: select
+options:
+ - "1 year from substantial completion"
+ - "2 years from substantial completion"
+default: "1 year from substantial completion"
+```
+
+The Contractor shall warrant the polishing workmanship — the aggregate exposure, the gloss and clarity, the densification, the joint and crack filling, and any dye, stain, or guard — against defective workmanship for the period stated. The Contractor shall be aware that the warranty does not extend to conditions inherent in the slab as placed and cured by others — inconsistent surface hardness, soft or dusting concrete, trowel burn, out-of-flatness, and inconsistent aggregate distribution — where those conditions were documented in the slab assessment and their effect on the achievable finish was disclosed; those are concrete defects, not polishing defects. Joint-fill separation arising from continued slab drying shrinkage after filling, and dulling or etching caused by cleaning or spills contrary to the maintenance program, are excluded from the workmanship warranty.
+
+```datasheet
+label: Densifier / Guard Manufacturer Warranty
+type: radio
+options:
+ - "Manufacturer standard product warranty for densifier and guard"
+ - "Not required"
+default: "Manufacturer standard product warranty for densifier and guard"
+```
+
+Where offered, the densifier and guard manufacturers shall warrant their products against manufacturing defects for their standard warranty periods, executed in the Owner's name. Product warranties for densifiers and guards cover the material, not the appearance of the finished floor, which is governed by the workmanship warranty and by the slab conditions documented in the assessment.