The call came in on a Tuesday in early March 2024. A commercial contractor we work with—let's call him Dan—didn't do small talk. "I've got a lobby floor tenting up like a potato chip bag. 4,000 square feet. The owner wants answers."
"Tenting" is never the word you want to hear. Not on a Tuesday. Not ever.
Who I Am and Why I Get That Call
I'm a quality compliance manager in the construction chemical industry. At Mapei, I review product batches, spec sheets, and jobsite failure reports before they reach customers—roughly 600 items a year. I rejected about 4% of first deliveries in 2024 for off-spec numbers or incomplete documentation. When a contractor has a failure, I'm one of the people they call first. Usually because they want to blame the product. Sometimes—like this time—because the product was never the problem.
One product I review constantly is Mapei Planipatch Plus, a polymer-modified patching compound. Mixed with Acrylic Latex Additive, it has one unglamorous job: making a damaged concrete slab flat enough to tile over. Sounds boring. Until the boring part is missing.
The Shortcut That Started It
Dan's crew had installed 24-inch by 48-inch rectified porcelain in a hotel lobby. On paper, the spec was right: Mapei tile adhesive products from the large-format tile (LFT) family—something like Ultraflex LFT—over a patched and primed slab.
In the field, things went sideways. The slab had low spots near the elevator bank. The original prep spec called for grinding, vacuuming, and applying Planipatch Plus with Acrylic Latex Additive, then letting it cure before any thinset went down. Dan went back and forth for two days between doing it right and staying on schedule. The patch system offered reliability; skipping it offered about $3,000 in savings and a two-day head start. He skipped it. He told me later he second-guessed that decision the first night—then rationalized it in the morning.
When I got to the site, the evidence was everywhere. I walked the lobby with a mallet and the hollow sound covered roughly 30% of the floor. Three cracked tiles. Grout lines pulling apart in clusters. Red flags, all of them. On the polished concrete, you could see the lows he'd tried to "absorb" with thinset: a half-inch thick under some tiles, paper-thin under others. No patch, no uniform bond line—just an uneven substrate hiding under beautiful tile.
Same tile. Same thinset. Different substrate. That's the difference between a floor that lasts and a floor that pops.
The Epoxy and Acetone Twist
Here's where it got interesting. The epoxy resin grout work had been done right. But because the substrate was moving underneath, the stress split the tile right through those rigid epoxy joints. A crew member asked whether they could heat acetone to soften the epoxy residue on the tile faces. That's when I stopped the conversation.
Heating acetone to speed anything up is a hard no. Acetone has a flash point of -20°C (-4°F). It's a Class IB flammable liquid. Even gentle heat creates vapors that are heavier than air—they can travel along the floor to an ignition source you didn't even know was there. (Ugh. I have this conversation more often than I'd like.)
The safe cleanup is the grout manufacturer's cleaner with resin-safe pads, not a makeshift polishing compound for epoxy resin whipped up on-site. I've had this exact discussion with more than one contractor this year: reaching for a generic abrasive or a hotter solvent instead of a product designed for epoxy residue.
The Redo: Boring, By the Book
The fix took ten days. We popped the tile in the failed zones, brought in a dedicated prep crew, ground the slab, vacuumed, checked moisture, primed, and floated the low spots with Planipatch Plus and Acrylic Latex Additive. The latex additive is probably the less glamorous half of that system, but it's the difference between a patch that bonds and a patch that peels.
Cure times came straight from the current Technical Data Sheet. When the thinset went down, it was mixed to spec, and the tile was set with full 95% coverage—the TCNA/ANSI requirement for large-format porcelain in dry interior areas. Epoxy joints went in clean, and the crew used the manufacturer's cleaner before the resin fully cured. Nobody was dreading the phone call.
There's something satisfying about a redo that's completely boring. That's the point of quality systems: nothing exciting happens when everything is done right. Dan put the total cost in the $22,000 ballpark once you counted labor, disposal, replacement tile, and the hotel rescheduling furniture deliveries. "Best $22,000 lesson I ever got," he said, half-laughing.
The lobby opened a week later. The owner asked who had fixed it. It took another bid, but Dan's team got the follow-up project—which more than covered the loss. The failed floor was Dan's brand for a week. The finished floor was his portfolio for years afterward.
Three Things I Tell Every Contractor Now
Surface prep is a specification, not a suggestion. The TCNA/ANSI substrate flatness benchmark for large-format tile is 1/8 inch in 10 feet (and 1/4 inch in 10 feet for standard tile). If the substrate doesn't meet that, a compliant adhesive—even one that passes ANSI A118.4 or A118.15 bond strength tests—is working against a failing surface. The adhesive is half the system. The prep is the other half.
Use the whole product system. Mapei Planipatch Plus is tested as a system with Acrylic Latex Additive. Mixing with water instead changes the cured properties. I get why skipping it is tempting—budgets are real, and "patching" sounds like a step you can trim. But you're not using the product that was tested. (Note to self: we should put that warning in bigger type on the data sheet.)
Don't get inventive with cleanup. For epoxy resin, use the grout manufacturer's cleaner, not solvent tricks. And if you're googling "can you heat acetone"—no. Use it cold, ventilate the space, keep ignition sources away, and let it evaporate.
And If You Got Here by Accident
Our website search logs bring some interesting guests to this page, so let me save you a click. If you're looking for "pvef polymer lithium ion battery binder pvef," odds are you mean PVDF (polyvinylidene fluoride), the standard binder for lithium-ion battery cathodes. That's a different industry entirely—our polymers go into floors, not battery cells. You probably want a specialty fluoropolymer supplier.
And if you're asking for a polishing compound for epoxy resin: check the resin manufacturer's maintenance guide before buying a generic compound. The wrong abrasive will dull an epoxy finish faster than years of foot traffic.
Bottom line: the floor is the contract. It's what your client sees every day and the most expensive thing to redo. Whether it's Planipatch Plus under the thinset or the cleaner you choose for epoxy residue, every step is a brand decision. Trust me on this one—I'm the person who reads the paperwork after a floor fails.