Epoxy Floor Repair & Recoat in Ottawa & the National Capital Region - Re-Grind and Restoration Professionals

Diagnosing and Fixing a Failed Epoxy Floor

Failed epoxy typically fails one of three ways. It peels at the edges, it bubbles and lifts, or it wears through in high-traffic zones. Root cause almost always sits in one of three buckets: bad prep (acid etched rather than diamond ground), moisture vapour driving up from below, or a budget solvent-based product that was the wrong call from the start.

We identify which one is happening, remove the failed coating mechanically, repair the substrate, and recoat in 100% solid commercial-grade epoxy. Done correctly, the recoated floor carries the same Warranty as a fresh install from Ottawa’s full-spectrum epoxy flooring contractor. Where the slab itself is damaged, the recoat starts with proper concrete repair and restoration before any new coating goes down.

Anti-slip upgrades are also offered for floors that are otherwise sound but slippery. A grit broadcast goes down under a fresh traffic-resistant topcoat for commercial kitchens, medical facilities, and pool decks.

What’s Included

• Failure diagnosis (prep, moisture, or material)
• Mechanical removal of failed coating via diamond grinding
• Substrate repair: crack stitching, spall patching, moisture mitigation
• Fresh 100% solid epoxy system installation
• Anti-slip grit broadcast upgrade option
• Warranty on the new system
• Documented before/after for your records

Why Epoxy Floors Peel, and How We Fix a Failed Install

Delamination and peeling trace to one of three failure modes, and each demands a different corrective path. The first is inadequate surface preparation, specifically acid etching in place of mechanical diamond grinding. Acid etching raises surface pH and leaves contamination in the pores, producing a profile well below the CSP 2 to 3 that most 100% solid epoxy systems require for a durable mechanical bond. Floors installed this way in older Nepean and Orleans residential garages, where budget contractors are common, typically start lifting at the edges inside six to eighteen months.

The second failure mode is moisture vapour transmission. Ottawa’s Leda clay soil generates sustained hydrostatic pressure against below-grade slabs, particularly in Centretown and The Glebe where older slab construction runs to the 1960s and 1970s without a below-slab polyethylene vapour barrier. ASTM F2170 in-situ relative humidity probes on these slabs routinely return readings above 85% RH, well beyond the 75 to 80% threshold specified by commercial epoxy manufacturers. Apply a solvent-based or low-solid water-based coating over a slab in that condition and vapour pressure builds behind the film, producing the signature blister-and-bubble pattern many Ottawa homeowners mistake for a product defect.

The third failure mode is material selection. Solvent-based epoxy paints sold at home improvement retailers usually contain 30 to 50% solids by volume. Solvent evaporates during cure, so dry film thickness drops to 2 to 4 mils, roughly one-tenth the 20 to 40 mil build of a commercial 100% solid system. That thin film has almost no structural resistance to abrasion or thermal cycling, and Ottawa’s 80 to 100 freeze-thaw cycles per winter accelerate delamination well beyond what happens in a milder climate. In all three cases, the corrective sequence opens with mechanical removal using a 10-inch or larger planetary grinder running 16 or 30-grit PCD tooling, then ASTM F2170 moisture testing, substrate repair, a moisture-mitigating primer where readings exceed threshold, and a fresh 100% solid epoxy system as the base coat. New coatings never go over failed ones.

How We Diagnose a Failed Epoxy Floor Before Quoting

Most contractors offering epoxy repair quote from photos or a quick walkthrough. We use a structured diagnostic before a number lands on paper, because misdiagnosing the failure mode means the repair will fail the same way the original install did.

Diagnostics open with an ASTM F2170 in-situ relative humidity test. Two probes are drilled to 40% of slab depth and sealed for 24 hours. The reading tells us whether moisture vapour drive is actively contributing or whether the failure was purely mechanical. Centretown and Sandy Hill slabs from the 1960s and 1970s almost always return readings above 80% RH because they have no below-slab vapour barrier, which makes a moisture-tolerant primer mandatory, not optional, before any recoat. Skip that test and apply a standard epoxy primer over a high-RH slab, and the same blister-and-bubble failure repeats within one winter.

Next comes a pull-off adhesion test using a portable ASTM D4541 pneumatic dolly. A 50 mm aluminium disc is glued to the failed coating, the adhesive is allowed to cure, and the disc is pulled with a controlled force gauge. Readings above 200 psi at the concrete interface confirm the substrate is sound for a recoat. Readings below 150 psi, or failures that pull aggregate off the concrete face with the disc, confirm the substrate itself is compromised and needs to be ground back further than the coating delamination zone before a new system can bond reliably.

The third step is a scrape-and-probe inspection of delamination boundaries. Failed coatings rarely fail uniformly. There is usually a well-defined perimeter where bonded and unbonded zones meet. That boundary is mapped across the floor and the delamination percentage is calculated. If unbonded area covers more than 30% of the total floor, a full strip-and-recoat is almost always more economical than trying to address isolated patches. Under that threshold, mechanical removal of the failed zones and feathering the repair edges into intact coating produces a visually clean, structurally sound result.

The diagnostic report (moisture readings, adhesion results, and delamination map) goes to the client before the quote, so you know exactly why the floor failed and what is being done to prevent the same outcome on the next system.

Recoat vs Full Replacement: When to Do Which

Four variables drive the recoat-versus-replace decision: extent of delamination, condition of the substrate, number of previously applied coating layers, and the client’s budget ceiling. A recoat, meaning mechanical removal of the failed system, substrate repair, and fresh 100% solid application, is the right call when delamination covers under roughly 30% of the floor and the concrete underneath shows no widespread spalling or structural cracking. In that case, a full recoat on a standard two-car garage in Barrhaven or Orleans typically runs $1,600 to $2,900 CAD depending on substrate repair scope, versus $3,500 to $5,200 CAD for a full strip-and-reinstall with a fresh decorative flake or quartz broadcast system.

Full replacement makes economic sense in two scenarios. First, when the existing floor has received multiple coatings over the years (stacked layers of paint, solvent-based epoxy, and failed topcoats totalling 15 to 25 mils of built-up film with poor intercoat adhesion throughout). Grinding through that stack is labour-intensive, and the prep cost often approaches the cost of starting fresh. Second, when the slab is heavily spalled or scaled and surface deterioration exceeds what crack stitching and spall patching can economically address. On slabs like this, particularly in older Kanata industrial units, the correct path is a full skim coat of polymer-modified cementitious overlay to re-establish a flat, sound substrate, then a fresh system on top.

For floors that are structurally sound but showing surface wear (loss of gloss, fine abrasion scratches, or fading colour in high-traffic wheel paths) a topcoat recoat is a practical intermediate option. The existing coating is scuff-sanded to CSP 1 using 60-grit abrasive, wiped with a solvent wash, then a fresh 100% aliphatic polyurea or polyaspartic topcoat is applied at 3 to 5 mils DFT. Topcoat-only recoats on a sound base typically run $4 to $7 per sq ft installed, making them the most cost-effective way to add five to ten years of service life before a full system replacement is warranted.

Related Questions Ottawa Homeowners Ask

How do I know if the floor can be recoated versus needing full replacement?

Pull up a corner of the existing coating and read the bond. If the epoxy breaks adhesively at the concrete interface rather than cohesively through the film, the substrate is likely sound enough for a recoat after mechanical re-grinding. If the concrete face crumbles or pulls away with the coating, the slab itself is deteriorating and a full assessment, including ASTM F2170 moisture testing, is the right starting point before committing to any system.

How long does the repair take

Most residential repair and recoat jobs wrap in two days. Day one covers diamond grinding, substrate repair, and the moisture-mitigating primer. Day two covers the 100% solid base coat and polyaspartic topcoat. A polyaspartic finish is walkable at 24 hours and vehicle-ready at 72. Larger commercial floors in Nepean or Kanata warehouses may take three to four days depending on floor area and the number of isolated spall repairs required.

What does it cost to fix a peeling garage floor

A diagnostic, full mechanical re-grind, moisture-mitigation primer, and 100% solid recoat on a two-car garage (400 to 500 sq ft) typically runs $1,600 to $2,900 CAD depending on substrate condition. Anti-slip topcoat upgrades on a sound existing floor start at roughly $550 to $850 CAD for the same footprint. Floors with widespread spalling or multiple failed coating layers requiring extra grinding time sit at the higher end of that range.

Can moisture in a slab be corrected before recoating?

Yes, and it must be addressed before any new coating goes down, otherwise the same failure repeats. A two-component moisture-mitigating epoxy primer formulated to tolerate slab RH up to 98% goes on first, chemically bonding to concrete even under active vapour drive. Where hydrostatic pressure is persistent, the moisture primer is combined with a negative-side crystalline waterproofing treatment applied at the slab perimeter. That combination is a common requirement in below-grade garages and basement floors across Centretown and The Glebe where Leda clay drives constant moisture pressure.

Is an anti-slip upgrade safe for commercial kitchens and CFIA-regulated facilities?

Yes, provided the grit broadcast material and topcoat are food-safe and hit the coefficient of friction values specified under CFIA facility standards. Aluminium oxide broadcast aggregate goes under a 100% solid aliphatic epoxy or polyurea topcoat that is non-porous, seamless, and compatible with steam cleaning and commercial sanitisers. Kanata and Nepean facilities handling or storing food should confirm NFPA 1 slip-resistance ratings during scoping so the correct aggregate size and broadcast density can be locked to the floor’s traffic pattern.