Not directly. Old epoxy has to come off first via diamond grinding. Applying new coating over a failing epoxy layer inherits its adhesion problems — if the old epoxy lifts, your new coating goes with it. We grind to clean concrete, then install a fresh system. This is routine work for us and probably 1 in 4 jobs I do.
If you've got an old epoxy floor that's chipping, peeling, or just looking tired, you're not stuck with it. Here's what replacing it actually looks like.
Why can't we just coat over the old epoxy?
Because the new coating's lifespan is capped by the weakest link underneath it. If the old epoxy has any adhesion issues — and most failing epoxy floors do — anything we put on top is only as good as that bond. When the old epoxy lets go, the new coating lifts with it. You'd spend money on a new install and still be in the same spot a year later.
Even if the old epoxy looks solid in most areas, there's usually hidden debonding at edges, under vehicles, or in areas with moisture. I'd rather grind it off and start from clean concrete than gamble on a layer I can't inspect. Gambling on unseen layers is how contractors end up doing warranty work on their own dime.
There's also a compatibility question. Epoxy and polyurea are different chemistries with different surface energies. Adhesion between them can be unpredictable without a specific primer, and even then it's a weaker bond than polyurea to bare concrete.
How hard is it to remove old epoxy?
Depends on how well it was applied originally. Ironic but true — well-bonded epoxy is harder to grind off than poorly bonded epoxy. Poorly bonded epoxy comes up in sheets. Well-bonded epoxy takes a full diamond grinding pass with aggressive tooling.
Either way, it comes up. A planetary grinder with PCD (polycrystalline diamond) tooling or aggressive metal-bond segments chews through epoxy fast. We adjust the tooling based on what the floor is doing. Most garage-sized floors get stripped and re-profiled in the same time it takes to prep a bare concrete slab — maybe 30-60 minutes longer for removal.
After grinding, we want CSP 2-3 profile on clean concrete with zero epoxy remaining. Not patches of epoxy, not thin residual. Clean concrete all the way across.
Does removal cost extra?
Usually a small add — not double the price. On residential jobs I typically quote the removal as part of prep rather than a separate line item, unless the old coating is especially nasty or thick. If the old epoxy is already 90% off the floor due to failure, it might cost even less than fresh concrete prep because there's less actual grinding needed.
I'll give you a straight number on the first call once I know what we're dealing with. Our pricing page has the ballpark on standard installs.
What about DIY epoxy kits from the box store?
Same answer: grind it off. Box-store epoxy kits (you know the ones — roll-on kit, decorative flakes in a bag, comes with an etching bottle) are typically 1-2 mils thick and poorly bonded. Most of them come up almost on their own after a year or two in a Wisconsin garage.
If you've got a failed DIY kit on your floor, that's actually one of the easiest removals. The kit peels up in big pieces, then we grind away whatever's stuck and move on. I wrote about this specifically in why DIY epoxy failed.
Will the new floor be as good as if the concrete had never been coated?
Yes. Once we've ground down to clean, profiled concrete, the new Valence system doesn't know or care what was on top before. Bond strength, coating thickness, and long-term performance are identical to a brand-new slab install. The 674 PSI bond strength and 15-year warranty apply the same way.
In some ways it's easier than a new slab. Old slabs with 10+ years of cure behind them have less residual moisture than fresh concrete, which means cleaner MVER results and less risk. A 20-year-old garage slab is about as dry and stable as concrete gets.
What if there's old sealer under the epoxy?
Gets ground off too. Some homeowners had their floor sealed once and then epoxied over it, which is part of why the epoxy failed in the first place — it was bonded to sealer, not concrete. Diamond grinding gets through all of that in a single pass.
Penetrating sealers that went deep into the concrete pores can be trickier, but that's rare in residential garages. If we hit unusual contamination during prep, we'll adjust on the fly. That's part of why I do my own grinding instead of subbing it out.
Can you leave some of the old epoxy as a transition?
No. You'd get a visible height change where the old coating meets the new, plus a weak bond line at that transition. Any place the old coating is staying, the new coating can lift from. Whole-floor grinding, whole-floor coating. It's just cleaner and longer-lasting.
What's the timeline for a removal + recoat job?
Usually the same day. Grind and remove in the morning, repair cracks and pits, basecoat, flake, topcoat. Walk on it the next morning, park on it 48 hours later. The timeline matches a fresh install — see what to expect installation day for the full step-by-step.
Really heavy removals or badly damaged slabs might need to split across two days, but I'll tell you that on the quote, not the day of.
Is the dust from grinding an issue?
We run HEPA-filtered vacuums on the grinder at all times. Dust collection is integral to the way we prep floors — not just for cleanliness, but because dust ruins the next step of the job. The garage will be cleaner after we grind than it was before we started, and the air quality stays reasonable throughout. If you're worried about dust getting into the attached house, close the door between the garage and house before we start and we'll do the rest.
I'm embarrassed about how bad my old epoxy looks
Don't be. Honestly, the worse it looks going in, the more rewarding the install is for both of us. Failed epoxy, oil stains, cracks, pitting, ugly colors — I've seen it all and I've fixed it all. The new Valence floor won't show any trace of what was there before.
Epoxy that was trendy ten years ago is why I get a lot of my calls now. Homeowners are ready to replace it with something that will actually last, and they usually don't love the color anyway. It's a chance to start over with a finish that matches the rest of the house.
Send me photos of the floor as-is, cracks and all. Get a free quote or call Dave at (715) 307-8302.