Polished Concrete
Summary
Polished concrete is a structural slab ground with progressively finer diamond tooling, treated with a chemical densifier, and polished to a specified sheen and aggregate exposure, sometimes with dyes and guards. It turns the slab into the finish at low life-cycle cost, but the result depends on slab placement, flatness, joint layout, and protection long before polishing starts.
Cols
Terminology
- Grit: abrasive fineness of diamond tooling; higher numbers polish finer
- Metal-bond / resin-bond diamonds: coarse grinding tools and finer polishing tools
- Densifier: sodium, potassium, or lithium silicate that reacts with the concrete to harden the surface
- Guard: penetrating or topical treatment that resists stains
- Aggregate exposure (class): cream (no aggregate), salt and pepper (fine aggregate), or medium to large aggregate exposure, set by grinding depth
- Sheen level: appearance from flat to highly polished, often measured by gloss meter (ASTM D523)
- Distinctness of image (DOI): clarity of reflections, measured by ASTM D5767
- Grind and seal: lower-cost finish with a topical coating rather than mechanical polish
- Burnishing: high-speed buffing of densified or guarded floors
Standards
Ratings
| Level | Final resin grit | Appearance |
|---|---|---|
| 1 | Below 100 | Flat, ground |
| 2 | About 400 | Satin, honed |
| 3 | 800 or higher | Semi-polished |
| 4 | 1,500 to 3,000 | Highly polished |
- Typical grit sequence: 30, 50, 100, 200, 400, 800, 1,500, 3,000, adjusted for concrete hardness
- Specify sheen level and aggregate exposure together; mockup required
Test standards
- ASTM D523: specular gloss
- ASTM D5767: distinctness of image
- ASTM E1155: floor flatness and levelness
- ANSI A326.3: dynamic coefficient of friction (DCOF) for hard surface flooring
Materials
- Concrete slab: consistent mix, placement, and finishing; avoid surface hardeners and curing compounds that block densifier
- Densifiers: lithium silicate common for low residue
- Dyes: solvent or water-based color applied between grinding steps
- Guards: stain-resistant topical treatments
- Joint fillers: semi-rigid polyurea or epoxy
Detailing
- Specify flatness (FF and FL) and finishing for the slab at placement, not at polishing
- Plan aggregate exposure from the slab pour: uniform aggregate and finish improve consistency
- Protect slab during construction from hydraulic leaks, rust, paint, and staining
- Lay out saw-cut joints as part of the visible pattern; fill after shrinkage
- Expect cracks; specify repair approach and acceptance criteria
- Coordinate slip resistance targets with sheen level for wet areas and entries
Uses
Specific uses
- Retail, big-box, and grocery floors
- Warehouses and distribution centers
- Offices, schools, and lobbies with an industrial aesthetic
- Restaurants and breweries
- Residential slabs on grade with radiant heat
Pros and cons
Pros
- Low cost when the slab is already required
- Very durable and abrasion resistant
- Low maintenance; no waxing or stripping
- High light reflectance
Cons
- Shows cracks, patches, and slab defects
- Hard, noisy, and cold underfoot
- Staining risk without guards
- Results vary with slab quality and installer skill
Manufacturing and cost
Construction
- Slab cured; surface ground with metal-bond diamonds to the specified exposure
- Densifier applied; honing and polishing with resin-bond diamonds through grit sequence
- Guard applied and burnished
Main manufacturers and suppliers
- Husqvarna Construction (grinding equipment)
- PROSOCO
- Euclid Chemical
- Sika USA
Trade association: American Society of Concrete Contractors (Concrete Polishing Council).
Typical costs
- Polished concrete over an existing slab, installed: $3 to $12 per sq ft, from basic densify and polish to high-gloss custom finishes
Sources
- Concrete Network: polished concrete levels, https://www.concretenetwork.com/concrete/polishing/levels.html
- Projul: concrete polishing and grinding guide, https://projul.com/blog/construction-concrete-polishing-grinding-guide
- For Construction Pros: polished concrete gets its own MasterFormat section, https://www.forconstructionpros.com/concrete/decorative/press-release/10368618/polished-concrete-gets-its-own-section-in-masterformat
- Solomon Colors: 03 35 43 polished concrete finish specification, https://solomoncolors.com/tech-docs/pdf/specifications/03-35-43---Polished-Concrete-Finish.pdf
- Terrapin Construction Group: commercial flooring cost per sq ft, 2026, https://terrapincg.com/news/commercial-flooring-costs-per-sf-2026
- Wikimedia Commons: Polished Concrete Floor.jpg, by Intellicents (CC BY-SA 4.0), https://commons.wikimedia.org/wiki/File:Polished_Concrete_Floor.jpg