1. Surface preparation method
Prep is the largest single cost variable and the one that determines the outcome. Diamond grinding to a CSP 2-3 profile opens the concrete so the coating can key into it mechanically. Shot blasting does the same job faster on large commercial floors. Acid etching does neither well and belongs nowhere near a system you expect to last.
Grinding an existing failed coating off adds meaningfully to the job, often $1.50 to $3.00 per square foot on top of the new system, because the old material loads up diamonds and slows everything down.
2. Slab moisture
Moisture vapor moving up through a slab is the leading cause of coating delamination. A calcium chloride test or in-situ relative humidity probe tells you whether the slab is dry enough. If it is not, a moisture-mitigating epoxy primer is required and adds roughly $1 to $2 per square foot.
This matters most in Gulf Coast humidity, on slabs with no vapor barrier beneath them, and on basement or below-grade floors. Skipping the test to keep a quote low is how you buy the same floor twice.
3. Cracks, spalls, and joints
- Hairline crazing: usually absorbed by a high-build base coat at no extra cost
- Static cracks: chased out, filled with a rigid polyurea, ground flush ($8 to $20 per linear foot
- Spalled or pitted areas: patched with a resin mortar) $6 to $15 per sq ft of repair area
- Control joints: filled and honored, or filled and coated over depending on movement
- Active, moving cracks: need a flexible system and will telegraph through regardless
4. Square footage
Setup, containment, grinder mobilization, and cleanup are fixed costs spread across the floor. Small jobs carry a higher per-square-foot rate, and many installers set a project minimum around $1,800 to $2,500 regardless of size. Combining a garage and an adjacent patio in one visit is usually cheaper per foot than two separate trips.
5. Coating system and decorative finish
| Choice | Effect on price |
|---|---|
| Solid color vs full flake | Flake adds roughly $1-$2 / sq ft |
| Epoxy topcoat vs polyaspartic topcoat | Polyaspartic adds roughly $1.50-$3 / sq ft |
| Quartz broadcast | Adds $2-$4 / sq ft over flake |
| Metallic artistry | Adds $3-$8 / sq ft, highly installer-dependent |
| Anti-slip additive | Adds $0.25-$0.75 / sq ft |
6. Access and site conditions
- Stairs, tight gates, and upper-floor slabs add labor and equipment handling
- Below-grade or unventilated spaces may require forced-air ventilation
- Cold slabs may require heating or a cold-cure formulation
- Floors that must be emptied and reloaded by the crew add hours
- Occupied commercial space with night-only work windows adds premium labor
The verdict
Price differences almost always trace back to prep depth, moisture mitigation, and repair scope. Ask every bidder to itemize those three and the comparison becomes simple.
A quote that does not mention how the slab will be profiled is not a quote you can evaluate.
Frequently asked questions
- What drives the biggest price difference between quotes?
- Surface prep. Diamond grinding with dust containment costs real labor hours, and it is the line item cheap bids delete first. Two quotes for the same square footage can differ by thousands based on prep alone.
- Does square footage lower the price per foot?
- Yes. Mobilization, grinding setup, and crew time spread across more area, so a 1,200 square foot shop usually prices lower per square foot than a 400 square foot single garage.
- Do cracks and spalling raise the cost?
- They do. Routing and filling cracks with polyurea, rebuilding spalled edges, and resurfacing pitted areas typically adds $0.75 to $2.50 per square foot depending on how much of the slab needs repair.
- Does moisture testing add to the price?
- Testing itself is inexpensive. A failing result is what costs money, because a vapor barrier primer adds roughly $1 to $2.50 per square foot. Skipping the test is how a floor bubbles six months later.
- Why do flake and metallic systems cost more?
- Both add material volume and labor. Full flake broadcast requires scraping and vacuuming before the topcoat, and metallic finishes are hand worked, so the artistry time shows up in the bid.