Can Ottawa contractors fix a slab that sank near the garage door before applying epoxy?

Yes, Ottawa contractors can absolutely address a sunken slab section near the garage door before applying epoxy — and addressing it is not optional if you want a coating that lasts. Applying epoxy over a settled or uneven slab without proper remediation is one of the most common reasons coatings fail prematurely, and it is a mistake that costs far more to fix the second time around.

What Causes Garage Slab Settlement Near the Door

The garage door threshold area is one of the most vulnerable spots on any Ottawa garage floor, and the local climate is largely to blame. The freeze-thaw cycle — Ottawa sees more than 50 of these per winter season — repeatedly expands and contracts the soil beneath the slab. Road salt and snowmelt carried in by vehicles saturate the soil near the entrance, and the frost line sitting between 1.2 and 1.5 metres deep means the ground movement is significant. Over time, the soil beneath the slab erodes or compresses unevenly, and the concrete follows it downward. You end up with a lip, a slope, or a visible crack line where the slab has dropped.

The two main remediation approaches contractors use in Ottawa are mudjacking (slabjacking) and polyurethane foam lifting, sometimes called foam jacking. Mudjacking pumps a slurry of cement, soil, and water beneath the slab through drilled holes to raise it back to grade. It is the older method and costs roughly $500 to $1,500 for a garage threshold area, depending on how much lift is needed. Polyurethane foam lifting is the newer approach — a two-part expanding foam is injected through smaller holes, lifts the slab quickly, and cures in about 15 minutes. It is lighter than mudjacking slurry, which means less ongoing load on compromised subgrade. Foam lifting typically runs $800 to $2,000 for a garage entrance area in Ottawa. Neither method is a permanent guarantee if the underlying drainage or soil issue is not corrected, so a good contractor will assess what caused the settlement before recommending a fix.

If the slab has sunk significantly — more than 50 to 75 millimetres — or if it is cracked through in multiple places, replacement of that slab section may be the more practical solution. A partial slab pour for a garage entrance area runs roughly $1,500 to $4,000 depending on the scope, and new concrete needs to cure for a minimum of 28 days before epoxy can be applied.

Once the slab is levelled, the surface still needs proper mechanical preparation before any coating goes down. Diamond grinding is the standard — it opens the concrete pores, removes any laitance or contamination, and creates the surface profile that epoxy bonds to. Skipping this step after slab repair is just as damaging as skipping it on an untouched floor. Budget an additional $2 to $5 per square foot for surface preparation on top of whatever remediation work is done.

From a permit standpoint, slab lifting and minor concrete repair on an existing residential garage floor generally does not require a City of Ottawa building permit. If the repair involves replacing a large section of slab or touches the foundation, it is worth a quick call to 3-1-1 to confirm.

For a project like this — slab remediation followed by epoxy coating — you really need a contractor who understands both the concrete repair side and the coating side. You can browse contractors who handle garage floor work through the Ottawa Construction Network directory at justynrookcontracting.com. Get at least three written quotes, and make sure each contractor walks the floor in person before pricing the job.