Can old paint or glue be removed from concrete before epoxy in my Ottawa home

Removing Old Paint or Glue From Concrete Before Epoxy in Ottawa

Yes, old paint and glue can absolutely be removed from concrete before epoxy application, and in fact they must be removed — applying epoxy over existing paint or adhesive residue is one of the most common causes of coating failure. Professional Ottawa contractors deal with this regularly, especially in basements where carpet glue, tile mastic, and old floor paint are frequently found under removed flooring, and in garages that previous owners painted with hardware-store floor paint.

Diamond grinding is the most versatile and commonly used method for removing paint and thin adhesive layers from Ottawa home concrete floors. A walk-behind planetary grinder fitted with aggressive PCD (polycrystalline diamond) tooling or carbide-tipped segments can strip most paints and thin adhesives in a single pass while simultaneously profiling the concrete for epoxy adhesion. For a standard basement or garage, mechanical grinding to remove old paint costs $2 to $4 per square foot in Ottawa — slightly more than grinding bare concrete because the tooling wears faster cutting through coatings.

Shot blasting is particularly effective for thick or stubborn coatings. If the garage floor has multiple layers of paint built up over decades, or if a previous epoxy coating failed and needs complete removal, shot blasting strips everything down to raw concrete quickly. Expect to pay $2.50 to $5.00 per square foot for shot blasting with heavy coating removal.

For carpet glue and tile mastic — extremely common in Ottawa basement renovation projects — the removal method depends on the adhesive type and thickness. Black cutback adhesive (common under tiles installed before the 1980s) may contain asbestos and requires professional testing before disturbance — this is an Ontario regulatory requirement, not optional. Non-asbestos adhesives are typically removed with a scarifier or floor scraper attachment followed by diamond grinding, costing $3 to $6 per square foot. Thick glue deposits may benefit from a chemical adhesive remover applied first to soften the residue, then mechanical removal — this two-step approach adds cost but reduces grinding time and tooling wear.

Chemical strippers are available for paint removal, including citrus-based and soy-based products that are lower in volatile organic compounds. They work by softening the paint so it can be scraped or pressure-washed off. Chemical stripping costs $2 to $5 per square foot including labour and materials. The downside is that chemical residue must be thoroughly neutralized and rinsed before epoxy application, and the floor still needs mechanical profiling afterward. Most Ottawa contractors prefer to skip chemicals and go straight to mechanical removal for efficiency.

One important Ottawa-specific consideration: if paint or adhesive has been sealing the concrete for years, removing it may reveal higher-than-expected moisture levels underneath. The old coating was effectively acting as a vapour barrier, and once it is gone, moisture from Ottawa's clay soils and seasonal water table fluctuations can push through freely. Always insist on a moisture vapour test after stripping and before coating. If emission rates exceed 3 pounds per 1,000 square feet per 24 hours, a moisture-mitigating primer is required before the epoxy system.

Total cost for removal and preparation in an Ottawa home typically runs $1,500 to $4,000 for a 500-to-700-square-foot space, depending on what is being removed and how many layers are present. This is a necessary investment — the Ottawa Construction Network directory at justynrookcontracting.com can help you find flooring contractors who have the right equipment and experience to handle your specific situation efficiently.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• Luxe Painting and Renovations
• RenoMotion Inc.
• Custom By Arie
• Timely Touchups Construction
• Capital City Drywall