Floors
Epoxy floor installation cost
A two-car garage in proper 100% solids epoxy runs about $2,170 installed — $5.42 a square foot — or about $910 in materials and grinder hire doing it yourself. But the number that should decide it is cost per year of service, which nobody publishes: the cheap one-part paint works out at $614 a year and the real epoxy at $144. Coverage here is calculated from solids and film thickness rather than read off the tin, because tins quote it at half the thickness they recommend.
Drafted with AI assistance, edited by Pablo Ruiz Quintero
Published 2026-09-18 · Nothing you type leaves your browser
Epoxy floor installation calculator
The floor
How much product a floor takes is not the number on the tin. It is 1,604 ft² per gallon per mil, times the solids, divided by the film thickness the maker specifies — and that is worked out here rather than quoted.
A two-car garage is usually about 20 × 20.
Measure the slab, not the outside of the building.
Nothing evaporates, so the film you roll on is the film you keep. Ten times the thickness of paint in one coat — and a pot life of about forty minutes, which is why this is the system where amateurs get caught.
The standard the coating makers actually specify. It cuts a mechanical profile the coating keys into, and it removes whatever was on the floor before. Machine hire is around $120 a day.
Splash some water on it. What it does in the next minute is the test, and it changes how much product the first coat takes.
Vinyl chips into the wet coat. A full broadcast uses five times as much and needs a topcoat over it.
Takes the wear and the UV. On a flake floor it is not optional.
The difference is the grinder, the pot life and somebody else's warranty.
Used only to pick a regional labour rate. It stays in your browser.
Installed
$2,166
400 ft² · 3 gal · $5 a ft²
$144 a year over 15 years
Full rated life, because the preparation is what the coating maker specifies. This is the only line on the page that buys years rather than looks.
Coverage, worked out
1,604 ÷ mils × solids. One line, and it decides the whole shopping list.
- Volume solids100%
- Film the maker specifies10 mils
- So a gallon covers160 ft²
- What a label would quote321 ft²
- The slab drinks, first coat0.5 gal
Label coverage is usually stated at about half the recommended thickness. It is not a lie — it is the answer to a different question, and buying to it leaves you with half the film you paid for and a floor that fails early.
What doing it yourself would cost
$906
You would keep $1,260 and take on the preparation and the pot life. The materials are the same; what you are buying is somebody who has done it before.
What each system costs per year of service
Same floor, same preparation. Only the product changes.
Shopping list
- 100% solids epoxy, 1 coat
160 ft² a gallon at 10 mils — including 0.5 gal the slab absorbs on the first pass3 gal - Vinyl flake, partial
A light scatter to hide trowel marks, patches and dust, and to give some grip2 lb - Clear topcoat
Takes the wear, the UV and the tyre marks. On a flake floor it is what makes the surface flat1.2 gal - Calcium chloride moisture test
A calcium chloride kit is about $45 and takes 72 hours. If the slab is pushing more than 3 lb per 1,000 ft² per day, or sitting above 75 per cent internal humidity, the coating will lift no matter how well it was applied — and no amount of preparation fixes vapour drive from underneath.$45
What it costs
National average. Coating, flake, topcoat, diamond grind and the moisture test, plus application labour. Crack and joint repair, levelling a slab that is out of flat, and removing an old failing coating are separate and can be substantial.
$5 a square foot, $144 a year of service. The concrete underneath is its own job — see concrete slab if it is being poured, and floor installation if this is a room rather than a garage.
Worth knowing
- 3 gallons of 100% solids epoxy, worked out from coverage rather than read off the tin. At 100 per cent volume solids and the 10 mil film the maker specifies, a gallon covers 160 ft² — not the 321 ft² a label would quote, because label figures are usually stated at about half the recommended thickness.
- The arithmetic is one line: 1604 ft² per gallon per mil at 100 per cent solids, times 100 per cent, divided by 10 mils. Which is why a thin coating covers MORE floor per gallon and lasts less — high coverage is a thin film, and nobody selling by the gallon puts it that way.
- 0.5 gallons of that is what the slab drinks on the first coat — 20 per cent, for a typical garage slab, water darkens it slowly. The normal case. The first coat loses about a fifth into the surface. It is the commonest reason a job runs out of material two thirds of the way across the floor.
- Before anything else, test the slab for moisture. A calcium chloride kit is about $45 and takes 72 hours. If the slab is pushing more than 3 lb per 1,000 ft² per day, or sitting above 75 per cent internal humidity, the coating will lift no matter how well it was applied — and no amount of preparation fixes vapour drive from underneath. The $45 kit is in this total, and it is the cheapest line on the page against the most expensive failure.
- Pot life. Once the two parts are mixed, a 100 per cent solids epoxy gives you about forty minutes — and it gets shorter as the garage gets warmer, because the reaction makes its own heat. Mix in small batches, never the whole kit, and have a second pair of hands. This is the step where a competent DIYer loses a floor.
- Installed by a contractor. The same floor done yourself would be about $906 in materials and machine hire — a difference of $1,260, which is what you are paying for the grinder, the pot life and somebody else's warranty.
- 24 hours before you can walk on it and 7 days before a car goes back in. Parking early is the second way these floors fail: hot tyres pull at a coating that has not finished cross-linking, and the mark never comes out.
On this page — 6 sections
What an epoxy floor costs
The short version
- About $2,170 installed for a two-car garage in proper 100% solids epoxy — $5.42 a square foot. $910 in materials doing it yourself.
- The cheapest system costs four times more to own. One-part paint is $614 a year of service; 100% solids epoxy is $144.
- Coverage is arithmetic, not a label. 1,604 ÷ mils × solids. Tins quote it at half the recommended thickness.
- Two checks decide whether it lasts, and both cost less than the coating: a $45 moisture test and grinding instead of etching.
$2,170
Two-car garage, installed
100% solids, flake, topcoat, ground
$910
The same floor yourself
Materials and grinder hire
$5.42
Per square foot installed
The figure everyone publishes
$144
Per year of service
The figure nobody publishes
Every guide to this job prices it by the square foot, and that is the one metric under which a three-year coating beats a fifteen-year one. It is worth seeing what happens when you divide by the years instead.
MaterialsEstimator, Garage floor coating price estimates · checked 2026-09-18
The rule of 1,604, which decides your shopping list
A gallon of anything, spread perfectly at one thousandth of an inch, covers 1,604 square feet. That is a geometric fact — 231 cubic inches divided by 0.001 inches, converted — and every coverage figure in this trade comes out of it.
coverage (ft² per gallon) = 1,604 × volume solids ÷ mils of dry film
- volume solids
- the share of the tin that stays on the floor once the water or solvent leaves
- mils
- thousandths of an inch of dry film — the thickness the maker specifies, not the thinnest it can be spread
Worked through — 100% solids epoxy at 10 mils: 1,604 × 1.00 ÷ 10 = 160 ft² a gallon. One-part paint at 40% solids and 3 mils: 1,604 × 0.40 ÷ 3 = 214 ft² a gallon.
| System | Solids | Mils | ft² / gal | Life | What it is |
|---|---|---|---|---|---|
| One-part epoxy paint | 40% | 3 | 214 | 3 yr | Not really epoxy — a latex paint with some epoxy in it, sold in one can because it does not need mixing. It is what most big-box kits are, it goes on easily, and hot tyres will lift it within a few summers. |
| Two-part water-based epoxy | 50% | 5 | 160 | 7 yr | A genuine two-part epoxy thinned with water. Forgiving to apply, low odour, and it breathes a little — which is an advantage on a slab with some moisture in it and a disadvantage everywhere else. |
| 100% solids epoxy | 100% | 10 | 160 | 15 yr | Nothing evaporates, so the film you roll on is the film you keep. Ten times the thickness of paint in one coat — and a pot life of about forty minutes, which is why this is the system where amateurs get caught. |
| Polyaspartic / polyurea | 90% | 8 | 180 | 20 yr | Cures in hours rather than days, does not yellow in sunlight, and stays flexible in the cold. It is what professional one-day garage floors are, and the pot life can be under twenty minutes. |
MaterialsEstimator, Coating coverage and solids content estimates · checked 2026-09-18
The $45 test that decides everything
Concrete on the ground is a wick. Unless there is an intact vapour barrier under the slab — and in most garages built before the 1980s there is not — ground water moves up through it continuously and leaves as vapour at the surface.
A coating stops that vapour. The vapour does not stop, so pressure builds under the film until it lifts, in blisters or in sheets. No amount of surface preparation fixes this, because the problem is not the bond, it is what is pushing on it from behind.
$45
Calcium chloride kit
72 hours, ASTM F1869
3 lb
The limit
Per 1,000 ft² per day
75%
Or internal RH
In-situ probe, ASTM F2170
$2,170
What it protects
Which is why this is the best-value line
ASTM International, ASTM F1869 and F2170, moisture in concrete slabs · checked 2026-09-18
Grinding against etching, which is the other half of the answer
A coating does not glue itself to concrete. It keys into a texture, and producing that texture is what preparation means.
Acid etching — the sachet in every DIY kit — dissolves a little cement paste and opens the surface slightly. On a soft, old, bare slab it does something. On a power-trowelled garage floor, which is dense and closed by design, it does very little, and it leaves salts behind that undermine the bond unless rinsed exhaustively and dried completely.
Diamond grinding cuts a mechanical profile. It is what every coating manufacturer actually specifies in their data sheet, and it is the difference between a floor that lasts 15 years and one that lasts 9.
| Diamond grind | Acid etch | |
|---|---|---|
| On a 400 ft² floor | About $540 | About $200 |
| Doing it yourself | ~$120 a day for the grinder | The sachet in the kit |
| Works on a dense, trowelled slab | Yes | Barely |
| Removes old coating and contamination | Yes | No |
| Leaves residue to rinse | Dust, vacuumed | Salts, and they matter |
| What the coating maker specifies | This | Not this |
| Expected life on this floor | 15 years | 9 years |
And a third thing about preparation that nobody mentions: grinding makes the floor drink more. An opened surface takes more of the first coat than a closed one, so the better-prepared floor needs more product. The calculator above accounts for it — splash some water on the slab and see what happens in the next minute.
| What the water does | First coat lost | What it means |
|---|---|---|
| Sealed or very dense, water beads on it | 5% | A slab that repels water will also repel coating. It has to be opened up mechanically or nothing will bond, whatever the tin says. |
| Typical garage slab, water darkens it slowly | 20% | The normal case. The first coat loses about a fifth into the surface. |
| Porous or old, water soaks straight in | 40% | A thirsty slab can take nearly half the first coat. This is where a job runs out of material two thirds of the way across the floor. |
SSPC / AMPP, Surface preparation standards for concrete, SSPC-SP 13 / NACE No. 6 · checked 2026-09-18
Doing it yourself, and where people lose the floor
The saving is real: about $1,260 on a two-car garage, which is more than half the job. What you are taking on is not the rolling — it is the grinder and the clock.
The order, and it does not bend
- Moisture test first, 72 hours before anything else. If it fails, stop and price mitigation.
- Empty the garage completely. There is no doing half a floor.
- Fill cracks and control joints, and let the filler cure.
- Grind the whole slab, edges included — a hand grinder for the perimeter the big machine cannot reach.
- Vacuum, then vacuum again. Dust is a bond breaker and it is invisible once the coating is wet.
- Check the temperature: most systems want 55-85°F on the slab, not in the air, and a cold slab will not cure.
- Mix small batches. Never the whole kit.
- Cut the edges, then roll toward the door. Work out, not in.
- Throw the flake into wet coating, from above, letting it fall rather than aiming it.
- Stay off it. Walking early marks it, parking early lifts it, and neither comes out.
What goes wrong
01Buying by the coverage figure on the tin
It is usually quoted at about half the recommended film thickness, so you end up with half the film you paid for. And the thinner system looks like better value precisely because it covers more per gallon.
Instead — Work it out: 1,604 ÷ mils × solids. Then add what the slab absorbs on the first coat, which the label never mentions.
02Skipping the moisture test
Vapour driving up through a slab lifts a coating from underneath and no preparation prevents it. Most warranties exclude moisture-related failure, which means the risk is yours whoever applied it.
Instead — A $45 calcium chloride kit and 72 hours, before you buy anything. It is the cheapest line on the page and it protects the most expensive one.
03Acid etching instead of grinding
It is what comes in the kit, it barely touches a power-trowelled slab, and it leaves salts that undermine the bond. It is the commonest reason a floor comes up in sheets.
Instead — Hire a grinder for about $120 a day. On this floor it is the difference between 9 years and 15.
04Comparing systems by price per square foot
It is the one metric that makes a three-year coating beat a fifteen-year one, and it is the only metric anybody publishes.
Instead — Divide by the years. One-part paint is $614 a year of service on this floor; 100% solids epoxy is $144.
05Mixing the whole kit at once
Pot life is forty minutes for solids epoxy and can be under twenty for polyaspartic, and it shortens as the material heats itself. There is no pause button.
Instead — Small batches, a second person opening tins, and start at the far corner so you are never working back across wet floor.
06Coating over cracks and open joints
A coating bridges nothing. Whatever moves underneath telegraphs through and splits the film within a season, usually along exactly the line you were trying to hide.
Instead — Fill cracks with the right filler for whether they move, fill or deliberately carry through the control joints, and let it cure before coating.
07Parking too soon
A warm tyre pulls at a coating that has not finished cross-linking. The mark is permanent and it is always in the most visible part of the floor.
Instead — Wait the full cure — 7 days for solids epoxy, 1 for polyaspartic — and longer if the garage is cold, because cure time is temperature-dependent.
08Coating a cold slab
Most systems want the concrete itself between 55 and 85°F. A slab in an unheated garage in November is colder than the air, and a coating that does not cure stays soft indefinitely.
Instead — Measure the slab temperature, not the air, and do this job in the shoulder seasons rather than the extremes.
If the concrete is not down yet, this is the moment that decides everything above: a vapour barrier under the slab, a thickened edge and a sensible joint layout make the coating job straightforward instead of a gamble.
Pouring the slab first?Common questions
- How much does it cost to install an epoxy floor?
- About $2,170 for a two-car garage — 400 ft² — in 100% solids epoxy with flake, a clear topcoat and proper grinding, installed. That is $5.42 a square foot. The same floor with the same materials done yourself is about $910, or $2.27 a square foot, and the difference is the grinder, the pot life and somebody else's warranty.
- How much does epoxy cost per square foot?
- Installed on a two-car garage with flake and a clear topcoat, about $3.75 a square foot for one-part paint applied over an acid etch, $5.33 to $5.42 for a proper two-part epoxy, and $7.27 for polyaspartic. But per square foot is the wrong metric, and it is the only one anybody publishes: on cost per year of service those numbers reverse completely.
- How many gallons of epoxy do I need for a 2-car garage?
- About 3 gallons of 100% solids epoxy for 400 ft², including the half gallon the slab absorbs on the first pass. That comes from arithmetic, not a label: 1,604 ft² per gallon per mil, times 100 per cent solids, divided by the 10 mil film the maker specifies — so 160 ft² a gallon.
- Why does the coverage on the tin not match?
- Because label coverage is nearly always quoted at about half the recommended film thickness. It is not dishonest — it is the answer to a different question — but buying to it leaves you with half the film you thought you were paying for. A 100 per cent solids epoxy covers 160 ft² a gallon at its specified 10 mils and 321 at half of it.
- Is the cheap epoxy paint from the hardware store worth it?
- It depends what you are buying it for. One-part epoxy paint costs about $1,840 installed on a 400 ft² floor against $2,170 for real 100% solids epoxy — but it lasts about 3 years against 15. Per year of service that is $614 against $144, so the cheap option costs more than four times as much to own. If you are selling the house in two years it is the right buy. Otherwise it is not.
- Do I have to grind the floor, or can I acid etch?
- Grind. Acid etching is what comes in a DIY kit, it opens a dense slab barely at all, and it leaves salts behind unless rinsed exhaustively. On this floor it takes the expected life from 15 years to about 9 — you are giving away years to save a few hundred dollars on the one step that decides whether any of it stays down. Grinder hire is around $120 a day.
- Why do epoxy floors peel?
- Two reasons, almost always, and both are checkable before you spend anything. Inadequate preparation, so the coating never keys into the concrete — that is the peeling-in-sheets failure. And moisture driving up through the slab, which lifts the coating from underneath no matter how well it was applied. The second is why a $45 test kit is the best value item on this page.
- How do I know if my slab is too damp to coat?
- Run a calcium chloride test — ASTM F1869 — or an in-situ relative humidity probe. Above about 3 lb per 1,000 ft² per day, or 75 per cent internal humidity, you need a moisture mitigation primer or you should not coat at all. A slab on grade with no vapour barrier under it, which describes most garages built before the 1980s, is the usual culprit.
- How long before I can park on a new epoxy floor?
- About 7 days for 100% solids epoxy and 1 for polyaspartic, against 24 and 4 hours respectively before you can walk on it. Parking early is the second commonest way these floors fail: a warm tyre pulls at a coating that has not finished cross-linking, and the mark is permanent.
- Epoxy or polyaspartic?
- Polyaspartic costs about a third more, cures in a day rather than a week, does not yellow in sunlight and stays flexible in the cold. Epoxy is cheaper, more forgiving to apply and builds a thicker film in one coat. Per year of service they come out close — 15 years against 20 — so choose on how long the garage can be out of use and whether it gets direct sun.
- Can I do this myself?
- The one-part and water-based systems, comfortably. The 100% solids and polyaspartic ones are where people lose floors, because once mixed you have forty minutes — often less in a warm garage — and there is no stopping halfway. Hire the grinder either way; it is the step that matters most and the one DIY kits skip.
- What about cracks in the concrete?
- Fill them before coating, with a semi-rigid joint filler or an epoxy crack filler depending on whether they move. A coating bridges nothing — anything moving underneath telegraphs through and splits it within a season. Control joints should be filled too, and honestly discussed: some installers fill them and some carry them through the coating, and both are defensible as long as somebody decided.
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About the author
Pablo Ruiz Quintero — Editor
Editor of MaterialsEstimator. Decides which documents count as a source, what every default value is, and where the line sits between what the reader parses and what the engines compute.
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