How much does it cost to grind down high spots before coating my Ottawa garage floor?

Grinding down high spots on a garage floor in Ottawa typically costs $3 to $8 per square foot for the grinding work alone, depending on the severity of the high spots and the total area that needs attention. Most contractors charge a minimum of $500 to $800 for floor grinding, even on smaller jobs, because the equipment setup and dust containment requirements make very small jobs uneconomical.

Floor grinding becomes necessary when concrete slabs have settled unevenly, developed ridges from poor finishing, or have existing coatings that need removal before applying new epoxy or polyaspartic floor systems. In Ottawa's freeze-thaw climate, garage slabs are particularly prone to developing high spots and low areas as the ground shifts seasonally. Salt damage from winter road treatments can also create uneven surfaces as the concrete deteriorates at different rates across the slab.

The grinding process uses diamond-embedded discs to remove high spots and create a uniform profile for coating adhesion. Professional contractors use industrial grinders with dust collection systems to contain the concrete dust, which is crucial for both health and cleanliness. The depth of grinding depends on the severity of the high spots — minor leveling might remove only 1-2 millimeters of concrete, while more significant corrections could require grinding down 5-10 millimeters or more in problem areas.

Important considerations include the age and thickness of your slab. If your garage floor is the minimum 4-inch thickness common in older Ottawa homes, aggressive grinding could weaken the slab structure. Slabs with significant cracking, widespread spalling, or structural issues may not be good candidates for grinding and coating — sometimes a concrete overlay or complete replacement makes more sense economically.

Most Ottawa floor coating contractors include minor surface preparation in their base pricing, but significant grinding is typically quoted separately. Get the grinding and coating quoted together from the same contractor when possible, as this ensures proper surface preparation and eliminates finger-pointing if adhesion problems develop later. The total project cost including grinding and a quality polyaspartic coating system usually ranges from $8 to $15 per square foot for a typical two-car garage.

If you're dealing with substantial floor issues that require professional grinding and coating, you can browse garage floor specialists through the Ottawa Construction Network directory to compare local contractors who handle both the preparation and coating phases of the project.