What Is Polished Concrete?
Polished concrete is not a coating applied on top of existing concrete — it is a mechanical process that converts the concrete slab itself into the finished floor. Diamond-embedded tooling cuts progressively finer scratches into the surface, and chemical densifiers penetrate and harden the matrix. The result is a permanent, low-maintenance floor with no surface film to delaminate.
Toronto commercial clients choose polished concrete for retail stores, office lobbies, manufacturing floors, institutional buildings, and residential lofts. It can be combined with dyes for colour, aggregate exposure for texture, and guard coatings for stain resistance.
Grit Progression Explained
The polishing process follows a fixed grit progression. Each pass removes the scratch marks from the previous grit. Skipping grits leaves visible swirl marks in the finished floor.
| Phase | Grit Range | Purpose | Tooling |
|---|---|---|---|
| Coarse grinding | 16–50 grit | Remove coatings, level slab, expose aggregate | Metal bond diamonds |
| Medium grinding | 80–100 grit | Remove coarse scratch pattern | Metal bond diamonds |
| Fine grinding | 200–400 grit | Refine surface; densifier applied here | Transition/hybrid bonds |
| Polishing | 800–1500 grit | Develop reflectivity | Resin bond diamonds |
| High polish | 3000 grit | Mirror finish | Fine resin bond / buff pads |
Concrete densifier (lithium or sodium silicate) is applied between the 200 and 400 grit passes. Applying it earlier wastes densifier on an overly open matrix; applying it later reduces penetration depth. Timing is critical — this is one of the most common errors in DIY or under-trained polishing crews.
CSDA Sheen Classes
The Concrete Sawing and Drilling Association (CSDA) defines four sheen classes for polished concrete based on distinctness of image (DOI) measurement.
| Class | Finish Name | Final Grit | DOI Range | Best For |
|---|---|---|---|---|
| Class 1 | Flat/Matte/Ground | 400 grit | 0–20 | Warehouses, light industrial, utility spaces |
| Class 2 | Satin | 800 grit | 20–55 | Commercial retail, offices, schools |
| Class 3 | Semi-Gloss | 1500 grit | 55–70 | High-traffic retail, hospitality, restaurants |
| Class 4 | High-Gloss / Mirror | 3000 grit | 70+ | Showrooms, luxury retail, upscale lobbies |
Aggregate Exposure Levels
How aggressively the slab is ground determines how much of the concrete aggregate becomes visible in the finished floor. Three levels are standard.
| Level | Appearance | Grinding Required | Premium |
|---|---|---|---|
| Cream (A) | Paste surface only — no aggregate visible | Minimal, 400+ grit start | Base price |
| Salt & Pepper (B) | Small aggregate pinholes and fine stones visible | Medium (100–200 grit start) | +$1–$2/sq ft |
| Full Aggregate (C) | Large stones, terrazzo-like appearance | Heavy (16–50 grit start) | +$2–$3/sq ft |
2026 Concrete Polishing Pricing — Toronto
| Sheen Class | Price Range | Includes |
|---|---|---|
| Class 1 (Matte/Ground) | $4–$7/sq ft | Surface grind, densifier, flat finish |
| Class 2 (Satin) | $7–$10/sq ft | Full grind progression, densifier, guard coat |
| Class 3 (Semi-Gloss) | $9–$14/sq ft | Full progression through 1500, densifier, guard coat |
| Class 4 (High-Gloss) | $12–$18/sq ft | Full progression through 3000, densifier, premium guard |
- Densifier and guard coating included in all ProEpoxy packages
- Crack repair (semi-rigid polyurea) $8–$20/linear ft depending on width
- Concrete dye add-on: $1.50–$3/sq ft for single colour
- Mobilization included for projects over 3,000 sq ft; $350 flat fee under 3,000 sq ft
Frequently Asked Questions
What grit level do I need for polished concrete in Toronto?
The grit you finish at determines your sheen class. Class 1 (matte/ground) stops at 400 grit. Class 2 (satin) finishes at 800 grit. Class 3 (semi-gloss) finishes at 1500 grit. Class 4 (high-gloss/mirror) finishes at 3000 grit. Most Toronto commercial clients choose Class 2 (800 grit) for the balance of maintenance and visual quality. Class 4 is reserved for showrooms, lobbies, and high-end retail.
How much does concrete polishing cost in Toronto?
Concrete polishing in Toronto costs $4–$7/sq ft for Class 1 (ground), $7–$10/sq ft for Class 2 (satin), $9–$14/sq ft for Class 3 (semi-gloss), and $12–$18/sq ft for Class 4 (high-gloss). Densifier and guard are included in all ProEpoxy polishing packages. Aggregate exposure add-ons cost $1–$3/sq ft extra.
How long does polished concrete last in a Toronto commercial space?
Polished concrete with a penetrating guard coating typically lasts 10–20 years before refinishing is needed. Unlike topcoat coatings that sit on the surface and can delaminate, polished concrete is a permanent conversion of the slab surface. High-traffic areas may need re-densification and guard re-application every 5–7 years.
Can you polish a concrete floor in an existing Toronto building?
Yes. Existing slabs in Toronto commercial buildings are polished regularly. Prerequisites: slab must be free of oil contamination, structural cracks must be filled with semi-rigid polyurea caulk, and any coatings must be shot-blasted or ground off first. Retail conversions, industrial retrofits, and loft residential polishing are all common ProEpoxy project types.
Does polished concrete qualify for LEED credits in Ontario?
Yes. Polished concrete can contribute to LEED BD+C credits in Materials and Resources (recycled content), Indoor Environmental Quality (low VOC materials), and Sustainable Sites. ProEpoxy can provide material data sheets and VOC content documentation for LEED submissions.