Failed Floor Removal & Recoating

Assessment

Adhesion pull tests, moisture testing, core review

Removal

Shot blast, PCD grind, scarify

Common causes

Poor prep, moisture, contamination, wrong system

Outcome

Corrected substrate + correctly specified system

The four things that usually went wrong

Inadequate prep. The floor was acid etched, pressure washed or simply cleaned instead of mechanically profiled, so the coating never keyed into the concrete. This is the most common cause by a wide margin.

Moisture. Vapor drive from below pushed the coating off the slab. This produces blisters that often contain liquid and typically shows up months after installation.

Contamination. Oil, grease, silicone or curing compound left in the slab prevented a bond in patches, which is why the failure looks random rather than uniform.

Wrong system for the exposure. A standard epoxy installed where there is thermal shock, steam cleaning or aggressive chemistry will fail no matter how well it was installed.

Diagnosis before demolition

Adhesion testing tells you whether the coating released from the concrete or the concrete itself failed below the bond line. Those two results lead to very different fixes.

Moisture testing establishes whether vapor drive is a live problem that will destroy the next floor too.

Looking at the failure pattern helps: uniform blistering across a slab on grade points at moisture, while patchy release near equipment points at contamination.

Partial versus full removal

If most of the existing system is well bonded and only isolated areas have released, a repair-and-recoat is possible: remove the loose material, feather the edges, patch and recoat the field.

If pull tests come back low across the floor, full removal is the honest answer. Recoating over a weak bond just adds weight to something already letting go.

The cost difference is real, so the testing that decides it is worth doing properly rather than guessing.

Specifying so it does not happen again

The replacement system is chosen against the actual exposure in the building: what is spilled, how hot it gets, what cleans it, and what drives across it.

Where moisture readings are high, a mitigation membrane goes in first. Where chemistry is aggressive, the resin changes. Where impact is the issue, thickness increases.

Prep is documented, profile is verified against the manufacturer's requirement, and the system goes down at the specified film thickness rather than stretched thin.

What a proper assessment includes

An assessment that leads to a reliable recommendation covers four things, and skipping any of them turns the recommendation into a guess.

Adhesion testing establishes how well the existing system is attached and, critically, where the failure plane sits. A coating that releases cleanly from concrete failed at the bond. A coating that comes away with concrete attached to the back means the concrete surface itself was weak, which is a different problem with a different fix.

Moisture testing establishes whether vapour drive is live. This matters even when the visible failure looks mechanical, because a moisture problem that goes unaddressed will destroy the replacement as reliably as it destroyed the original.

Mapping the failure pattern is the third element. Uniform blistering across a slab on grade points at moisture; patchy release near equipment points at contamination; failure concentrated at a fryer or a wash-down point indicates the system was wrong for the exposure. The pattern usually identifies the cause before any test confirms it.

Finally, identifying what is actually on the floor. Recoating requires compatibility, and an unknown existing system is a risk that testing a small area resolves cheaply.

Making sure it does not happen twice

The replacement specification should respond directly to whatever the assessment found. A moisture failure calls for a mitigation membrane, not a different brand of epoxy. A thermal shock failure calls for a system that moves with the concrete. A contamination failure calls for deeper mechanical removal than the original installer did.

Where the original failure was inadequate preparation, the fix is procedural rather than material: profile verified against the manufacturer's requirement and recorded before priming.

Keeping documentation from the replacement matters more than usual on these projects. Photographs of the prepared slab, moisture readings and profile verification form the record that distinguishes a good installation from an optimistic one, and it is the only evidence that exists once the floor is finished.

It is also worth asking what the warranty covers before signing. On a replacement floor, a labour warranty is the part that matters, because the original failure was almost certainly not the product.

Warranty, liability and getting it resolved

When a commercial floor fails early, the technical question and the commercial question run in parallel, and it helps to keep them separate.

The technical question is what caused it, and the answer comes from assessment rather than from argument. Adhesion testing, moisture readings and the failure pattern establish the cause with reasonable confidence, and that evidence exists independently of anybody's opinion.

The commercial question is who pays, and that turns on the contract and the warranty rather than on the physics. Material warranties from manufacturers cover the product and rarely cover labour. Installer warranties cover application and vary enormously in what they exclude, with preparation-related failures sometimes carved out entirely.

Documenting the failure promptly matters. Photographs, dates, the pattern of spread and any correspondence about the original installation all become harder to assemble as time passes, and warranty periods run whether or not anyone is looking at the floor.

Where the amounts are significant and the parties disagree, an independent flooring consultant rather than another contractor is usually the right professional to engage, because they have no interest in the replacement work.

For most buyers, though, the practical resolution is simply to fix it correctly. Understanding the cause well enough to specify a replacement that will not repeat the failure is worth more than recovering part of the original cost, and the two are not mutually exclusive.

Managing a failing floor in the meantime

Between discovering a failure and replacing the floor there is usually a gap, and how that period is handled affects both safety and the eventual cost of the repair.

Loose and lifting material should be removed rather than left. A partially detached sheet of coating is a trip hazard, and in a food or pharmaceutical environment fragments breaking off represent a contamination risk. Cutting back to sound, well-bonded material and leaving a clean edge is better than waiting.

Exposed concrete in the interim will absorb whatever is spilled on it, which can make the eventual preparation more difficult. Where practical, keeping the exposed area clean and dealing with spills promptly limits how deep contamination goes.

Document the failure as it progresses. Dated photographs showing how far it has spread are useful for a warranty discussion and genuinely useful for the assessment, because the rate and pattern of spread carry diagnostic information.

Temporary patching is occasionally worthwhile in a high-traffic or high-risk area, but it should be understood as a stopgap. Patching material applied over a floor that is failing for an underlying reason will fail in turn, and money spent there is generally better held for the permanent repair.

Finally, keep the area under review. Failures that appear stable often are not, and a floor that was a contained problem in one bay can become a building-wide one over a season.

Common questions