Why Your Old Garage Floor Coating Peeled — and How to Avoid the Replay
You can see it: the white discoloration under the coating, the lifting edges, the peeling sheet. An old coating that failed almost always tells you what to do differently next time.
The usual cause: prep, prep, prep
About 90% of coating failures trace back to inadequate surface preparation. Causes include:
• Skipped or insufficient profiling (concrete polished smooth doesn't bond)
• Acid etch instead of mechanical grinding (often inadequate)
• Coating applied over a contaminated surface (oil residue, dust, curing compounds)
• Moisture trapped under the coating from a slab that wasn't tested
• Coating applied in conditions outside the spec (too cold, too humid)
What proper re-prep looks like
If you're recoating a previously coated floor:
• All old coating must be removed mechanically — grinding or shot blasting
• The exposed concrete must be re-profiled to manufacturer spec (usually ICRI CSP 3-4)
• Moisture testing per ASTM F1869 (calcium chloride) or F2170 (in-situ RH) is non-negotiable
• Any cracks must be filled with semi-rigid polyurea or epoxy filler, sanded flush
Cost reality
Removing a failed coating typically doubles the cost of the recoat job. It's frustrating. It's also the only path to a coating that lasts.
What this means for you
If the new bid skips the removal-and-prep line items, ask why. The cheapest bid is usually the one that's going to peel again.
What contractors should know
Walking the customer through the prep — with photos of the grinder going to work — makes the cost story clear. Customers who see the work value it.
If the crew is already shooting this, the missing step is a system that turns the camera roll into a record. Jobsite photo documentation is what Supervisr is built around — the photo lands on the job with its time and location, and the paperwork fills in behind it.
The part nobody can see later
Most of what decides how this holds up gets covered before the job is over. Once it is closed in, the only record of how it went in is the photos taken while it was still open.
Supervisr's Floor Coatings QA model works from common industry practice and the installation instructions that ship with the materials. It can review floor coating photos for surface profile preparation, moisture test documentation, primer coverage, and broadcast or topcoat consistency. Upload photos of concrete surface profile (CSP grade), moisture test results, primer coverage, broadcast aggregate density, and topcoat application, and you'll get a documented evaluation back in minutes.
For a homeowner, that record is a straightforward way to understand what you paid for. For a contractor, it is the milestone documentation that stands behind a workmanship warranty years later, long after the crew has moved on to the next job.
About Supervisr
Supervisr is an AI quality-assurance platform for floor coatings. It works from common industry practice and manufacturer installation instructions, and analyzes prep and application photos to predict coating performance.
Contractors use Supervisr to document quality at each milestone — backing up a workmanship warranty and building a track record of work they can point to. Homeowners end up with a clear record of what went into their home. See how it works at supervisrapp.com.