Garage floor epoxy peeling
moderate 4–10 h
Tools: floor scraper, grinder with a diamond cup wheel (rental) or a pressure washer, shop vacuum, roller with a spiked roller for bubbles, plastic sheet and tape · Materials: moisture-tolerant epoxy or polyurea primer, high-build epoxy or polyaspartic top coat, degreaser, etching solution if grinding is not possible
Steps
- Tape a 60 cm (2-foot) square of plastic to the bare concrete for 24 hours: droplets under it mean moisture is coming up through the slab, and any coating will peel until that is addressed.
- Scrape and grind off every loose flake and all the old coating around it; a coating over a sealed or smooth surface has nothing to grip.
- Degrease the slab, then grind (or at least etch) to a texture like fine sandpaper, and vacuum until a cloth wiped across it comes up clean.
- Apply a moisture-tolerant primer thin and even, wait the labelled time, and put down the top coat with a spiked roller pass to release bubbles.
- Keep cars off for the full cure — usually a week for epoxy — and wait longer in cold weather; hot-tyre pick-up on a coating that has not cured is the classic failure.
- Park on a mat or use a top coat rated for hot tyres if your cars come in off the highway in summer.
Stop and call a pro if
- the plastic test shows moisture — the slab needs a vapour-mitigation primer applied by a coatings contractor
- the old coating covers the whole floor and is bonded in most places — full removal by grinding is a rental-machine day at minimum
- the concrete is cracked, dusting or spalling underneath
What a pro does that you can't
A coatings contractor shot-blasts the slab to the right profile, applies a moisture-mitigation primer and a polyaspartic system that cures in a day and shrugs off hot tyres, with a warranty behind it.
DIY cost: $150–400 in primer and top coat; grinder rental $80–150/day