Multiply your floor area by the rate on your quote, then add prep. Prep is where cheap coatings fail.
Prepis the line kits skipA coating is only as good as the slab under it. Moisture vapor from below peels epoxy rolled over dust. Ask what the quote includes for grinding, testing and crack repair.
Garage floor coating cost is your floor area times the quoted price per square foot, plus prep.
For example, 400 sq ft at $4 to $8 per sq ft, plus $400 of prep, comes to $2,000 to $3,600. We do not publish a national epoxy average.
Prep means grinding, moisture testing and crack repair. It decides whether the coating stays on.
Area, rate, prep
Type the numbers from your quote. Nothing is emailed.
—Coating + prep
—Coating
—Prep
What this assumed—
Your numbers, not a national average. HyreGarage does not coat floors.
Why do garage floor coatings peel?
Because the bond to the concrete fails, not the coating. Almost every peeling, bubbling or lifting floor comes down to one of three reasons.
Reason one: the surface was never opened up. Most garage slabs are finished smooth by machine, almost like glass. A coating needs a rough surface to grip.
Grinding or shot blasting makes that rough surface. The acid etch in a store-bought kit often does not, especially on a hard or sealed floor. The coating then sits on top, and the first hot tire can pull it off.
Reason two: the slab was damp and nobody tested it. Garage slabs usually have no vapor barrier underneath, unlike house slabs. Ground moisture keeps rising through the concrete.
Seal the top with a coating and the moisture gets trapped under it. It pushes the coating up in blisters. The coating did nothing wrong. The slab could not take it.
Reason three: oil and dirt in the concrete. Years of oil, brake fluid and tire residue soak in. Degreasing cleans the surface. What sits in the pores seeps back into the wet coating and stops it curing. Grinding removes that dirty layer.
What this means for quotes. When you compare two quotes, you are really comparing preparation. That is where the labor and equipment cost sit. A much cheaper quote usually skips the grinder.
Where does the money in a floor coating quote go?
Mostly into preparation, not the coating material. That is why the tool above keeps prep as its own line.
Illustrative. A third of the prep effort is one machine doing one job. It is the step a cheap quote leaves out.
Grinding. A grinder with diamond pads, or a shot blaster, goes over the whole floor, then edges and corners by hand. It is a day of loud, dusty work with costly equipment. This one step decides whether the coating lasts.
Moisture testing. Cheap and quick, and skipped more than any other step. See the tests below.
Crack and joint repair. Cracks move. A hard coating laid over a moving crack will show it, then split along it.
Control joints, the straight cuts in the slab, are meant to move. Ask whether they will be filled with a flexible filler, kept open through the coating, or ignored. Ignored is the wrong answer.
Degreasing and patching. Ordinary but needed. A chipped or pitted slab must be filled before it is coated. The filler must suit the coating going over it.
Masking, edging and clean-up. Plain work. It is what makes the floor look finished where it meets the walls.
Which moisture test should a garage floor get?
Ask for ASTM F2170, the in-slab humidity test, where you can. Asking which test a contractor runs quickly separates a careful quote from a hopeful one. A coating on an untested slab may not stay on.
A 75% reading under ASTM F2170 is a widely used pass point. It is not a universal rule. The number that counts for your floor is in the maker’s data sheet for the product being used.
Test
What it measures
Units
What it is good for
Where it falls short
ASTM F2170
A hole is drilled into the slab to a specified depth, sleeved, allowed to equilibrate, and read with a probe. It measures the moisture condition of the slab itself rather than what is leaving its surface.
% relative humidity within the slab
The more reliable of the two measured tests. It reads inside the slab, not just the surface. Many coating makers call for it.
Widely treated as the more reliable of the two. A reading at or below 75% RH is a common acceptance threshold, but the number that governs is the one in the coating manufacturer’s own data sheet.
ASTM F1869
A surface emission test. A dish of anhydrous calcium chloride is sealed under a dome on the slab and weighed before and after, and the weight gained is converted to an emission rate.
lb of water per 1,000 sq ft per 24 hours
An older, well-known test. Many older specifications are written around it.
It measures only the top layer of the slab, which is why it can pass on a slab that is wet deeper down.
ASTM D4263
Tape a square of plastic sheet to the slab, leave it 16 hours, and look for condensation or darkening underneath.
Pass / fail, by eye
A free check anyone can run before calling anybody. If it fails, you learned something important for nothing.
A qualitative indicator only. It can tell you a slab is definitely wet. It cannot tell you a slab is dry enough, and it is not a substitute for either test above.
Sources: ASTM F1869, ASTM F2170 and ASTM D4263 (ASTM International), retrieved 2026-09-05. HyreGarage does not test slabs and does not certify anyone’s floor.
Epoxy, polyaspartic or sealer: how does each one fail?
Each works when applied well to a suitable slab. They differ in what goes wrong when something is off. The last column shows that.
A rough guide only. Every figure depends on preparation. A polyaspartic coat on an unground slab will not outlast epoxy on a ground one.
System
What it involves
When you can use it
How it usually fails
DIY epoxy kit
One coat, acid-etch preparation
Days before you can park on it
Hot-tire pickup, and peeling anywhere the acid did not open the surface. Acid often fails on a smooth, machine-finished slab, which is what most garage floors are.
Professional epoxy
Primer, build coat, topcoat, ground preparation
About a week to full cure
Yellowing where sunlight reaches it, and moisture damage if the slab was never tested.
Polyaspartic / polyurea
Primer, broadcast flake, clear topcoat, ground preparation
Often usable the next day
It sets very fast, so an inexperienced installer struggles. The failure shows as roller marks and lap lines, not peeling.
Sealer only
Penetrating silane or siloxane
Hours
Nothing dramatic. It is simply not a coating. It cuts water and salt soaking in, and does nothing for looks or wear.
What is hot-tire pickup on a garage floor?
It is when a hot tire pulls the coating off the floor. It happens in garages, not basements or warehouses, and it is why some coatings fail here.
What happens
A tire just off the highway is hot and a little soft. Parked on a coated floor, it sits for hours, cooling and shrinking while pressed tight against the coating.
If the coating grips the concrete more weakly than the tire grips the coating, the tire takes the coating with it. You get a bare patch the shape of the tire.
It is a bond problem, not a product problem
Hot-tire pickup does not need a bad coating. It needs a coating that is not gripping the concrete. That leads back to whether the floor was ground.
That is why it is mostly a DIY-kit failure. The kit’s epoxy is fine. The kit uses acid, and acid does not open up a smooth, machine-finished slab.
What prevents it
A properly ground surface, a primer that suits the slab, and a full cure before you park on it. Cure time is the part you control, and the part most often cut short.
Makers give one time for walking and a longer one for cars. Parking on a floor that is only ready for walking is the most common way to ruin a good coating in its first week.
What to ask a contractor
"How will you grind the slab, and to what CSP?" CSP means concrete surface profile, a roughness scale. A contractor who answers with a number on the ICRI Guideline No. 310.2R scale owns the gear and knows the standard.
"How long before I can park on it?" If the answer is the same as the walk-on time, ask again.
How is a garage floor coating applied, step by step?
Test, clean, grind, repair, vacuum, prime, coat, cure. There are no safe shortcuts in the middle. If you are home while the crew works, this is what should happen, in this order.
1
Empty the garage and test the slab
Test before anything is decided. ASTM D4263 is free and takes overnight. ASTM F2170 needs drilled holes and time to settle, so book it ahead. It cannot be done that morning.
2
Degrease and remove dirt
Oil, brake fluid and battery acid soak in over the years. Washing cleans the surface. What sits in the pores comes off with the grinder in the next step. That is one more reason grinding is not optional.
3
Grind or shot blast the whole floor, then the edges by hand
The floor should visibly change color and texture. If a crew sprays acid, waits, rinses and starts coating, you are watching the failure go in. Ask what CSP they are working to on the ICRI Guideline No. 310.2R scale.
4
Repair cracks, joints, chips and pits
Do this after grinding, not before. Grinding reveals damage hidden under a sealed surface. Repair first and you repair twice.
5
Vacuum, then vacuum again
Grinding dust is the other common cause of a failed bond. Any dust left behind acts as a layer between the concrete and the primer.
6
Prime, and treat moisture here if the slab failed its test
A moisture-blocking primer is a specific product put down at a specific thickness. It is quietly dropped when a quote did not allow for it. Nothing on top survives if it was needed and skipped.
7
Build coat, flake if specified, then topcoat
Flake is thrown into the wet coat until no more sticks. The extra is scraped off next day before the clear coat. A thin, patchy flake layer means the coating was setting faster than the crew could work.
8
Cure: walking first, cars much later
Two different times, both on the data sheet. Parking on a floor at its walk-on time is the most common way an owner ruins a good coating in week one.
HyreGarage framework, drawn from the ASTM and ICRI documents cited on this page. We do not apply coatings, and this is not a how-to manual. It is here so you can recognize the job being done properly.
What should a garage floor coating quote include?
Eight things. Two quotes that both cover all eight can be fairly compared.
The prep method, named
Diamond grinding or shot blasting, and to what roughness. "Surface prep included" is not a method.
A surface roughness target on the ICRI Guideline No. 310.2R scale
The ICRI scale runs 1 to 10, from a barely-etched surface to a heavily scarified one. Coating makers set a target for each product. A contractor who names one works to a specification, not by eye.
The moisture test and the pass mark
ASTM F2170 or ASTM F1869, with the number the slab must meet, and what happens if it fails.
A plan if the slab fails the moisture test
The usual fix is a moisture-blocking primer, and it costs extra. It belongs in the quote as a possible extra, not as a surprise.
How cracks and control joints are handled
What they are filled with, and whether control joints stay open through the coating or get covered. Covering a moving joint means a crack in the finish.
The number of coats and the total thickness
Two coats of one product is not the same as primer, build coat and topcoat. Thickness decides how long it resists wear.
When you can walk on it, and when you can park on it
Two different times. The parking time is the one that matters, and the one most often left out.
What the warranty covers
Peeling is the failure worth covering. It is also often excluded for "substrate condition," which is exactly what the moisture test should have checked. Read that clause.
Can you coat a garage floor yourself?
Yes, in many cases. This is one of the few jobs on this site where DIY is reasonable, if you are honest about which job you are doing.
DIY is reasonable when
You rent a grinder and use it. This is the whole point. A rented floor grinder for a day is not expensive. It turns "kit on a smooth slab" into a job with a real chance.
You test for moisture first, even with the free plastic-sheet test. If it fails, you saved a weekend and the cost of materials.
You expect what the product can give. One coat of DIY epoxy on a well-ground slab, in a garage you do not park in daily, is a sensible result for the money.
You can leave the car outside for the full cure. Not the walk-on time. The full one.
Hire a contractor when
The slab has a known moisture problem. Moisture-blocking primers are specialty products applied to a specification. Get this wrong and everything on top is wasted.
You want a polyaspartic or polyurea system. It sets in minutes. It is hard to get right on a first try, and flake systems are a skill as much as a product.
The floor is chipped, pitted or badly cracked. The repair work before coating is the skilled part.
You want a real warranty. A DIY floor has none. That is fine if you knew it going in.
What can this floor coating calculator not do?
It has no price list. That is on purpose. The rates are yours, from a quote. We do not publish a national cost per square foot. Prep would dominate that number, and prep depends on a slab we have not seen.
It cannot test your slab. That is the most important input of all. It needs equipment and a hole in your floor.
It does not know your climate or your slab’s history. A garage over a high water table, or with a driveway draining toward the door, behaves differently from the same slab on a dry lot.
It does not name or rank products. HyreGarage does not sell or apply coatings, and takes no payment to list anyone. Every standard here belongs to ASTM International or ICRI. The pass figure for your floor is the one on your coating’s data sheet.
Your floor area times the quoted rate, plus prep. At 400 sq ft, $4 to $8 per sq ft and $400 of prep, that is $2,000 to $3,600. Those are example numbers, not a national average.
Why does garage floor epoxy peel?
Usually moisture or poor prep. Water vapor rising through the slab pushes the coating off. Epoxy rolled over dust or smooth concrete cannot grip. Grinding and a moisture test prevent most failures.
Should I test my garage floor for moisture before coating it?
Yes. ASTM F2170 measures humidity inside the slab, and ASTM F1869 measures vapor coming off the surface. The coating maker sets the pass mark. For F2170, 75% relative humidity is a common threshold.
Why is prep priced as a separate line?
Because prep is how cheap coatings fail. Two quotes at the same price per sq ft are not the same job if one grinds the floor and the other does not.
Is grinding better than acid etching?
Usually, yes. Grinding makes the rough surface a coating grips, called the concrete surface profile (CSP). Acid etching often does not, which is why many kit coatings peel.
Insulating and air-sealing an attached garage (US DOE Energy Saver, retrieved 2026-08-23. The garage as a building, not a coating price. Moisture and slab condition are building issues.)
Related
Garage costsWhat moves the price across garage work.