Project types
Garage floor concrete
The garage floor is cracked, pitted, stained, or has settled at the door.
A garage floor lives an unusual life: sheltered from rain and sun, but subject to vehicle loads, hot tyres, road salt carried in on those tyres through winter, and whatever gets spilled on it.
It is also the residential slab most likely to receive a coating, and the one where coating failures are most common — almost always for reasons that have nothing to do with the product.
The threshold step
A step where the garage floor meets the driveway apron is one of the most frequent garage complaints. It usually means the apron outside has settled, not that the garage floor has risen — the apron sits on ground disturbed during construction and driven over constantly.
That makes it a lifting job on the outside slab far more often than a garage floor job. Worth establishing which slab actually moved before agreeing to anything.
Coatings, and why they fail
Epoxy and polyaspartic garage floor systems work well on properly prepared, sound, dry slabs. Where they fail, the cause is nearly always bond: coating over a sealed or contaminated surface, skipping mechanical profiling in favour of acid etching alone, or coating a slab with moisture moving up through it.
Slabs poured without a vapour barrier beneath are the classic moisture case. If a slab is old enough that nobody knows what is under it, moisture testing before coating is a reasonable thing to ask for.
Cracks and settlement in a garage slab
Garage floor slabs crack for the same reasons other slabs do, and most of it is unremarkable. What is worth more attention is a crack with a height difference across it, or a slab that has settled noticeably in one area — that points at what is underneath rather than at the concrete.
Garage slabs can be lifted in the same way as exterior flatwork, and doing so before applying a coating is the right order.
Getting the garage ready
Coating a garage floor means emptying the garage completely, including anything mounted low on the walls, and keeping it empty for longer than most people expect. Ask for the full timeline before agreeing dates: preparation, application, cure before foot traffic, and cure before a vehicle returns are four different points and only the last one gives you the garage back.
Grinding or shot blasting produces a large amount of dust even with extraction running. Anything that stays in the space, and anything on the other side of a shared wall, is worth protecting.
It is also the right moment to deal with anything else on that slab. Crack repair, patching a spalled area and correcting a low spot are all far cheaper while the floor is bare and the equipment is on site than they will be once a finished coating is down.
What moves the price
We do not publish national dollar figures. A single average applied across every site, method and market gives you a confident-looking benchmark that is wrong for your job in an unknown direction. What does transfer between jobs is the structure of the price:
- Square footage.
- Preparation required, which dominates the cost on a previously sealed or contaminated slab.
- Coating system and number of coats.
- Crack and spall repair before coating.
- Whether the garage has to be emptied and for how long.
Local quotes decide actual pricing. If you want to compare two of them properly, the quote comparison guide covers how.
What to ask a contractor
- Which slab actually moved — the garage floor or the apron outside?
- How will the slab be mechanically prepared before coating?
- Have you tested for moisture, and what did you find?
- How long before vehicles can return?
- Does the warranty exclude peeling caused by moisture or bond failure?
Common questions
Why did my garage floor coating peel?
Most often preparation or moisture. A coating over a slab that was not mechanically profiled, or was still sealed from a previous treatment, or has vapour pushing up from below, will release regardless of product quality. Ask any new contractor how they will address whichever of those applies.
Should I coat a cracked garage floor?
Cracks should be addressed before coating, not covered by it, and moving cracks will come through whatever goes on top. If the slab has also settled, deal with that first — a coating on a settled slab is a well-finished settled slab.
Work it out, or judge the quote
Related guides
Sealing and coatings
Sealers, epoxy and garage-floor systems: what they protect against and what they do not.
Read more →Spalling concrete
Surface breaking away in chunks, often with aggregate showing — usually water, freezing and salt.
Read more →Concrete leveling
Raising settled slabs back toward their original height instead of tearing them out.
Read more →Residential slabs
Shed bases, porches, AC pads and other flatwork that does not fit a category.
Read more →Flaking and scaling
Thin layers lifting off the surface — a finishing, curing and freeze–thaw story.
Read more →