Failed Garage Floor Coating: What the Do-Over Costs
What taking off a peeling coating really adds over a bare-slab price, which conditions move the number, and why a removal line is often a pricing model rather than a physics problem.
For most peeling residential floors, removal adds nothing at all - because the diamond grind you are paying for on a bare slab is the removal. A failing coating comes up in the same passes that open the concrete profile, so at Everclad's flat $8 a square foot a do-over is quoted the same as a first-time floor. Where you see a separate removal line - commonly $1 to $3 a square foot, and $3 to $5 for thick or stubbornly bonded systems - it is usually because the base price was written for clean concrete and everything else is an extra. Two real conditions can genuinely move the number, and neither of them is the old coating itself.
On this page
Why removal shows up as a line at all
Two companies can charge the same total for the same garage and describe it completely differently. One publishes a low per-foot number for bare concrete and bills prep conditions on top - old coating, sealer, spalling, coving. The other publishes one all-in rate that already assumes the slab needs a full mechanical grind, because in this region it usually does.
Neither is dishonest by itself. The trouble is that a homeowner with a peeling floor cannot compare them, because the removal adder is invisible until someone has stood in the garage. That is the whole reason our number is a single flat rate: the grind, the crack and pit repairs, the base, the flake and the topcoat are inside it, so a failed floor and a clean slab are quoted alike. The grinding versus etching comparison explains what that prep stage actually involves.
What actually drives removal effort
Strip away the pricing language and removal cost is four physical things.
- How well it is still stuck. A coating that is already lifting is the easy case - the grinder catches an edge and takes sheets. A sound, well-prepped coating that is simply being replaced for looks fights back, pass after pass.
- How thick, and how many layers. One thin water-based DIY film is minutes. Twenty years of successive coats over a penetrating sealer is a different job, and needs coarser tooling that then has to be followed by finer passes to leave a profile the new system can bond to.
- What the material does to the tooling. Hard, brittle coatings shatter and vacuum away. Soft ones - floor paint, some mastics and adhesives - smear and load up the diamond segments, so the tooling has to be changed out mid-job.
- Dust control and disposal. Grinding concrete generates respirable crystalline silica, which is regulated work with required engineering controls under OSHA's construction silica standard. Vacuum-shrouded grinders and HEPA extraction are not optional, and the spoil has to leave the property.
Notice what is not on that list: the age of the coating, its color, or how bad it looks. A hideous floor can be trivial to remove and a decent-looking one can be brutal.
Removal effort by what is on your slab
| What is down there | How it comes off | Effect on an all-in price |
|---|---|---|
| DIY kit epoxy, already peeling | Lifts in sheets during the profile grind | None |
| Professional coating, dulled but bonded | Several passes, slower going | None to modest |
| Floor paint | Loads the tooling, needs coarse segments first | Modest |
| Penetrating sealer | Grind deeper to reach clean concrete | Modest |
| Several coats stacked over years | Coarse tooling, then re-profiling passes | Real adder |
| Thick industrial mortar or mastic | Scarify or shot blast, then grind | Top of the range |
| Coating over a wet slab | Grinding does not address the cause | Testing plus mitigation |
| Oil-saturated parking spot | Extra grinding, degrease, sometimes cut out and patch | Varies by area affected |
The short version
The old coating is rarely the expensive part. The slab underneath it is. Price the do-over on what the concrete needs, not on what is currently sitting on top of it.
The two things that really add cost
Moisture. A slab poured without an intact vapor barrier, or one sitting on saturated ground, pushes water vapor up through the concrete continuously. That pressure is what lifted the last coating, and grinding does not touch it. Diagnosing it means testing rather than guessing - in-slab relative humidity probes, the method set out in ASTM F2170, give a far better picture than taping plastic to the floor. High readings mean a moisture-tolerant primer or a vapor-suppression coat before the system goes down, and that is a genuine addition to the price, not a sales device.
Contaminated concrete. Years of oil under a parking spot soak in deeper than the grind reaches. In the Kenosha and Racine corridor, add the other local one: chloride from road salt, carried in on tires all winter and driven into an unheated attached garage slab that freezes and thaws every few days. Salt-damaged concrete at the door line can be scaled and friable, and friable concrete has to be repaired before it can be coated, whatever was on it before.
Both of these are why we assess a failed floor in person rather than from photographs. Our guide to why coatings fail works through each cause and how it is identified.
What the adder does to your number
Put the market removal rates against a real garage and the size of the exposure becomes obvious. A two-car bay is roughly 400 square feet.
| Removal rate on a 400 sq ft garage | What it adds | In context |
|---|---|---|
| $1 a square foot | $400 | Roughly a tenth of the job |
| $3 a square foot | $1,200 | More than a third of a typical all-in price |
| $5 a square foot | $2,000 | Approaching the cost of a whole first-time floor |
That spread is the problem, not the size of any single figure in it. A homeowner comparing a low headline rate against a flat rate is comparing a number that is finished against a number that is not, and the gap between them is decided by someone standing in your garage after you have already chosen. On a typical two-car bay our flat rate lands at ~$3,200 whether the slab is bare concrete or carries a failed coating, because the grinding stage is the same stage either way.
There is a second, quieter cost in a do-over that no quote shows: you are paying twice for the same square footage. Whatever the first floor cost is gone, and it is gone because of prep rather than product in the large majority of cases. That is the argument for spending the second time on the prep specification rather than on the thickest-sounding coating - the layer that failed is almost never the layer people were shopping for.
Reading three quotes on a failed floor
When you collect quotes on a do-over, the totals are less informative than the structure. Ask each company three questions.
Is removal inside the price or on top of it? If it is on top, ask for the per-foot rate and the assumption behind it, in writing, before install day. A removal line discovered by a crew already in your garage is the worst possible time to negotiate.
Did anyone test the slab for moisture? If your old floor blistered or lifted in the middle rather than at the edges, and no one has mentioned testing, that quote is for a job that will fail the same way.
What is the prep specification? A company that plans to chemically strip and acid-etch rather than mechanically grind is proposing to lay a new coating on the same weak footing as the old one. Our cost guide covers the full range of what garage coatings sell for and what sits behind each price band.
What you can recover from the first job
Before you buy a second floor, spend an hour on the first one. Dig out the paperwork and read the workmanship warranty, not the marketing sheet. Loss of bond, peeling and delamination are exactly what a real one covers, and a claim costs you nothing but time. Our warranty guide shows what genuine coverage reads like and which exclusions quietly remove it.
And check whether you need a full teardown at all. A floor that has only lost its gloss, with every edge tight, may be a candidate for abrading and recoating instead - a far cheaper path, and the tests are in our piece on recoating over an old floor. If those tests fail, the honest answer is to take it back to concrete and build it properly, which is what the flat $8 a square foot buys: full diamond grind, repairs, polyurea base, flake broadcast and a UV-stable polyaspartic topcoat, in a day. Get the all-in number for your garage, or if you are local, see garage floor coating in Kenosha.