Can Ottawa epoxy contractors install a seamless garage floor over old cracks and patches?

Yes, Ottawa epoxy contractors can absolutely install a seamless-looking garage floor coating over cracked and previously patched concrete — but the quality of the final result depends almost entirely on the preparation work done before a single drop of epoxy is applied. Understanding what that process involves will help you have a much more informed conversation with any contractor you bring in for quotes.

What Happens to Cracks and Patches Before Coating

The first step any professional will take is a thorough assessment of your existing cracks and patches. Not all cracks are equal. Hairline cracks (under 1 millimetre wide) that are stable and not actively moving can often be filled with a low-viscosity epoxy crack filler that wicks deep into the void by capillary action, creating a solid repair that bonds to the surrounding concrete. Wider structural cracks (over 3 millimetres) require more aggressive treatment — typically routing the crack into a consistent V or U profile, then filling with a semi-rigid polyurea or epoxy filler that can handle minor movement without re-cracking. Cracks that show signs of ongoing movement due to Ottawa's freeze-thaw cycles are a more serious concern and may require a professional concrete assessment before coating proceeds.

Old patches are a particular challenge in Ottawa garages because many homeowners have used mismatched repair products over the years — hydraulic cement, vinyl concrete patcher, and various hardware store fillers — that may not bond well to epoxy. A contractor will test the adhesion of these patches and grind them flush with the surrounding slab. Any patch that sounds hollow when tapped (the "tap test") needs to be removed and redone with a proper epoxy mortar or polymer-modified concrete mix before coating begins.

Diamond grinding is the non-negotiable step that makes a seamless finish possible. A professional-grade floor grinder opens the concrete's pores, removes surface contaminants, and creates a consistent concrete surface profile (CSP) that epoxy can mechanically bond to. Without this step, even the best epoxy will peel. Grinding also levels minor height differences between patches and the surrounding slab, which is what gives the finished floor that smooth, seamless appearance.

Realistic Costs for Ottawa Crack and Patch Repair

Surface preparation and crack repair in Ottawa typically adds $2 to $5 per square foot to your total project cost before the coating system is even factored in. For a standard two-car garage (roughly 400 to 500 square feet), expect crack filling and grinding prep to run $800 to $2,500 depending on the number and severity of cracks. The full installed cost of a 100 percent solids epoxy system with flake finish over a repaired garage floor in Ottawa runs $6 to $12 per square foot, or roughly $2,400 to $6,000 for a two-car garage. Polyaspartic systems, which are increasingly popular for their UV stability and faster return to service, run $8 to $15 per square foot installed.

Ottawa Climate Considerations

Ottawa's extreme freeze-thaw cycle — over 50 cycles per winter season — is the primary reason garage floors crack in the first place, and it is also why crack repairs must be done correctly. A semi-rigid filler is often preferred over rigid epoxy in crack repairs because it can flex slightly with seasonal concrete movement without opening up again. Spring is an important time to assess crack severity, as winter's frost heave can widen cracks that appeared stable in fall. Moisture testing is critical before any coating goes down — spring snowmelt pushes significant vapour through Ottawa slabs, and coating over a wet slab is one of the most common causes of epoxy failure in this region.

For a project like this, getting at least three written quotes is strongly recommended so you can compare how each contractor plans to handle your specific cracks and patches. You can browse flooring contractors in the Ottawa area through the Ottawa Construction Network directory at justynrookcontracting.com — it is a free resource where you can find and contact local contractors directly.