The short answer
Most commercial floor failures are not product failures. Across thousands of completed jobs, the same five causes come back again and again: moisture and liquid water, slab temperature, whatever was already on or in the slab, process steps that got skipped between coats, and the details, drains, cove, and joints, where almost every callback lives. Power and access problems finish the list, wrecking the schedules good installation depends on. Diagnose which of these you are looking at before you pay anyone to recoat, because a new floor over the same cause fails the same way.
Cause 1: Moisture and liquid water
Water is the most consistent troublemaker in the records, in three different forms.
Vapor from below. Moisture moves up through concrete as vapor and pushes against anything sealed over it. Coatings blister and peel when the slab is wetter than the system tolerates, which is why specifications commonly treat slab moisture above roughly 3 pounds as the point where a moisture vapor barrier belongs under the system, and why slabs get tested before coating rather than after a failure.
Liquid water during installation. Floors in operating food facilities get wet from the building, not the weather: freezer ice melt, cooler sprayers, and leaking pipes all show up in job records as install-day problems, causing bubbling, soft mixes, and failed sections when a system goes down over standing water. Even moisture tolerant systems need a surface that is damp at most, never flooded.
Water getting behind the floor afterward. Where wall panels meet the floor, a gap lets wash water run behind the system and attack the bond from the edge inward. Standard specifications require wall panels tight to the wall for exactly this reason. Roof leaks land in the same category: water from above undoes bond that was sound when placed.
Cause 2: Slab temperature
Concrete temperature quietly controls curing. Records include a cooler slab at about 45 degrees F against a roughly 60 degree F minimum for the system being installed, a job where the floor would not cure until heaters were brought in. Cold slabs also stretch drying times for sealers and slow epoxy cure overnight. At the other extreme, thermal shock, hot water or steam on a cool floor, stresses the bond line of rigid coatings every cycle. The symptoms are recognizable: soft or tacky coating, bubbling, sections that never hardened. The cause is rarely the mix; it is the slab temperature nobody measured.
Cause 3: What was already there
Old floors lie about their condition:
- Unbonded overlays. Existing coatings that sound solid can be poorly bonded, and a new system bonded to a failing old one inherits the failure. Sounding and test areas catch this before it becomes a callback.
- Overlays thicker than expected. Demo planned in hours runs into thick old floors and eats days; one polished concrete job slipped about a week on this alone.
- Cure and seal compounds on the slab. A slab sealed when it was built can block coating bond. In the records, one such slab needed relative humidity testing and a moisture barrier system before coating could proceed, a scope change discovered the hard way.
- Young concrete. New pour-backs need a full 28 days of cure before sealing, and systems set minimum concrete ages (30 days in the urethane cement specifications in the records). Coating green concrete traps moisture and invites failure.
Cause 4: Skipped process steps
The clearest single example in the epoxy records: delamination between coats where the recoat window, the period during which the next coat bonds chemically to the last, was missed and the floor was not sanded and tack-wiped before the next coat went down. The system separated exactly at that interface. The rule follows: surface preparation between coats is not optional polish, it is the bond. The same family of shortcuts produces cracks telegraphing through coatings spread straight over untreated joints, and soft finishes where a cure window was rushed to hand the space back early.
Cause 5: Drains, cove, and joints
Ask where callbacks happen and the records answer consistently: at the details. Drain work generates height and slope disputes, including the standing lesson that even a specified pitch of 1/8 inch per foot can still puddle where the slab or drain setting is off. Cove base generates touch-ups and go-backs, because it is hand work at the wall line. Joints generate filler that will not strike flush on uneven slabs and edges that keep breaking under forklifts. When you budget a floor, the details are where quality is decided.
And the schedule killers: power and access
Two causes never appear on a product data sheet. Large grinders and polishers need serious power, typically 480 volt three-phase. Where a site lacks it, generators fill in, and generator problems, overheating and failures, show up repeatedly in the records (five polished concrete jobs in a single year). Access is the other one: operating stores and plants limit when crews can work, and a plan that ignores the operation’s hours produces rushed cures and skipped steps, which loops straight back to Cause 4.
Symptom, likely cause, first check
| Symptom | Most likely cause | First check |
|---|---|---|
| Blisters or bubbles in a coating | Moisture vapor, or liquid water at install | Test slab moisture; look for leaks and melt water sources |
| Peeling in sheets, cleanly between coats | Missed recoat window without sanding | Ask for the prep records between coats |
| Soft, tacky, or slow curing floor | Cold slab | Measure slab temperature, not air temperature |
| Cracks in the coating mirroring the joints | Telegraphing from untreated joints | Check whether joints were treated before coating |
| Ponding near drains | Slope or drain height wrong | Flood test after washdown; check the pitch |
| Floor failing at walls and edges first | Water behind the system at the cove or panels | Inspect cove condition and panel gaps |
| Repeat joint spalls | Slab movement, voids, or wrong filler hardness | Sound the slab; check for rocking |
| Polish looks scratched or uneven | Grit sequence or soft slab | Review the pass sequence; check slab hardness |
What to do when you find a failure
Document before you disturb: photographs, locations, and when symptoms appeared. Do not authorize a recoat over an undiagnosed failure; new material over moisture, an unbonded overlay, or a missed prep step reproduces the failure at new cost. Open a small test section if needed, because most of these causes are visible the moment someone looks at the bond line and the slab beneath it.
Limitations
This guide reads patterns across many jobs; your floor has one specific history. Moisture readings, slab temperature, and the actual bond condition of your existing floor outrank any general pattern, and some causes need investigation beyond the floor itself. Treat the table as triage, not verdict.
Frequently asked questions
Our floor is only two years old and peeling. Is it the product?
Occasionally, but look first at moisture, the recoat window between coats, and what the coating was bonded to. Product defects rarely peel in clean sheets at one interface; process and moisture problems do exactly that.
Can a failing floor just be recoated?
Only after the cause is fixed. Recoating over vapor drive, an unbonded old coating, or standing water gives you the same failure with a newer date on it.
Why did the floor fail at the drains and walls but not in the middle?
Because that is where water, movement, and hand-finished details concentrate. The field of a floor is the easiest part to install well; drains, cove, and joints are where conditions get tested.
Does temperature really matter if the building is heated?
Air temperature is not slab temperature. Slabs in coolers, freezers, and on grade in winter run far colder than the room air, and curing chemistry follows the slab. Measure the concrete, not the thermostat.
How do we keep the next floor from failing the same way?
Specify the diagnosis into the scope: moisture testing before coating, temperature verified at install, existing overlays sounded and test-patched, recoat windows and inter-coat prep written down, and drains, cove, and joints treated as scope items with their own line items.
Looking at a floor that is failing early?
Early failure is information, if it gets read before it gets covered. If your floor is peeling, bubbling, ponding, or wearing years ahead of schedule, book a free consultation with a flooring consultant and walk through the symptoms and the install conditions before you budget a replacement.