Yes, you can coat a garage floor that has cracks. In most cases, that is exactly what a professional install handles every day. The key is that the coating itself does not fill cracks. The cracks have to be properly opened up, cleaned out, filled with the right repair product, cured, and ground flush before the polyaspartic base coat goes down. The one situation where you slow down and reassess is an active structural crack that is still moving, getting wider, or showing vertical displacement. Here is how to tell what you have, how it gets repaired, and what to honestly expect long-term.
Yes, but the Cracks Need to Be Repaired First
A common myth is that a thick epoxy or polyaspartic coating will hide and fill cracks on its own. It will not. Coatings are designed to bond to a clean, sound surface, not to fill voids. If a crack is left untreated and the coating goes over the top, two things can happen:
1. The coating sags into the crack as it cures, leaving a visible line.
2. The crack continues to move under the coating, and you eventually see it telegraph through.
Done right, the repair happens first, the coating goes on second, and the finished floor looks like a single continuous surface. Skipping the repair step is one of the easiest ways for a coating job to fail early, which is why a real quote always includes crack repair in the scope.
Types of Cracks You Might Be Looking At
Not every line in your concrete is the same problem. Four categories cover most of what you will see in a Grand Strand garage.
Hairline cracks
Thinner than a dime, often spreading from joints or edges. These are normal as concrete cures and moves with temperature swings. They are routine to repair and the most common type of crack we see in newer Myrtle Beach homes.
Wider stable cracks
Cracks that are clearly past hairline (wider than a dime) but are not actively moving. These need a more substantial repair product but are still very repairable.
Control joints (these are not really cracks)
The straight, intentional lines cut into your slab, often in a grid pattern. Sometimes you will see a thin white plastic strip in them. These are designed to give the concrete a place to crack in a controlled way as it dries. We handle these differently during install, often with a flexible filler or by leaving them visible as a design feature.
Active or structural cracks
These are the ones that need attention before a coating is even considered. Signs include:
– The crack is getting wider over time
– One side of the crack sits higher than the other (vertical displacement)
– Water is seeping up through it
– Sections of the slab are heaving or sinking
Active cracks usually point to something happening below the slab: a moisture issue, soil settlement, or movement at a footing. We will tell you straight if we see this during the on-site visit.
How a Pro Repairs Cracks Before Coating
The repair process is part of every install day on a cracked slab. Here is the basic flow:
1. **Crack chasing.** We open the crack with a saw or grinder to remove loose material and create clean, bondable edges.
2. **Vacuum and clean.** All dust and debris come out so the filler can bond directly to sound concrete.
3. **Fill with the right product.** We use industrial-grade polyaspartic, polyurea, or epoxy-based repair products depending on crack width, depth, and slab conditions. Big-box latex and acrylic crack fillers are not in our toolbox. They shrink, stay soft, and peel out under a real coating.
4. **Cure.** Most professional fillers cure in minutes to a few hours, which keeps the project on a one-day timeline.
5. **Diamond grind flush.** Once cured, the repair gets ground level with the surrounding concrete so the surface is smooth.
6. **Coat the floor.** Polyaspartic base coat, vinyl flake broadcast, scrape, polyaspartic top coat.
The result is a finished floor that reads as a single surface, with the repair locked in underneath.
When We Would Recommend a Slab Assessment First
We will pause and recommend a structural look before a coating goes on if your slab shows:
– **Cracks that are still actively growing.** Document widths now, measure again in a few weeks. If they are wider, the slab is still moving.
– **Vertical displacement.** A coating cannot stop or hide a step in the floor.
– **Heaving or sinking sections.** Soil-related movement that needs to be addressed below the slab.
– **Persistent moisture seeping through a crack.** This points to a water source under the concrete, which is common in coastal homes and which we cover in detail in our post on how coastal humidity affects your garage floor over time.
In any of these cases, the right call is to stabilize first, then coat. Putting a beautiful polyaspartic floor over a slab that is still moving is a waste of money.
Honest Expectations: Can a Crack Come Back?
Yes, sometimes. Concrete moves with temperature and humidity, and even a well-repaired crack can occasionally telegraph back through over the years. A few honest notes:
– **Hairline cracks rarely return** when repaired correctly and topped with a flexible polyaspartic system.
– **Vinyl flake helps a lot.** The visual texture from a multi-color flake blend makes any minor line that does show up far less visible than it would be on a solid-color floor.
– **Anyone promising you a coating will guarantee against future cracks is overpromising.** No coating system on the market can stop concrete from being concrete.
– **The good news:** our polyaspartic system flexes with the slab better than rigid epoxy, which is one of the reasons it holds up so much better long-term. We cover the durability differences in polyaspartic vs. epoxy in South Carolina.
> **Cracks in the slab are not a deal-breaker. They are part of nearly every garage floor we coat. The deal-breaker is leaving them untreated.**
Why DIY Crack Repair Usually Fails
Walking down the patch-and-filler aisle at a big-box store, you will see plenty of inexpensive options. Most of them are not built to live under a real coating:
– Latex and acrylic fillers stay soft and peel out
– Hardware-store concrete patches shrink as they cure
– Most DIY products skip the crack-chasing step that creates a clean bonding surface
– DIY repairs almost never get diamond-ground flush before coating
If a DIY repair fails after a coating goes down, removing the failed section and redoing it usually costs more than having the crack repaired correctly the first time. If your cracks are real signs that something bigger is going on with the floor, you can also revisit our list of 5 signs your garage floor needs to be coated to see what else might be developing.
Get Your Cracked Garage Floor Coated the Right Way
Ready for a Smooth, Sealed Garage Floor?
Garage Kings Myrtle Beach repairs cracks and installs polyaspartic garage floor coatings in one day, with your choice of a 10-year or 21-year warranty on materials and labor. Call 843-892-6060 or request a quote online for an on-site visit in Myrtle Beach, North Myrtle Beach, Garden City Beach, Murrells Inlet, Conway, Carolina Forest, and nearby Grand Strand communities.