Concrete floor coatings
Answers
These are the questions we get asked about coated concrete floors, answered the way we would answer them on the phone, with what is true in the southwest Twin Cities metro rather than what is true somewhere the ground does not freeze.
41 questions, answered in full.
The coatings themselves
What the material is, how the chemistries differ, and where a coating stops being the answer.
Flake, solid color or metallic: what is the difference?
Flake hides dirt and old slab repairs, solid color shows everything, and metallic is a swirled decorative finish for a room you spend time looking at.
Is a floor coating the same as garage floor paint?
Garage floor paint dries as a thin skin on the surface, a coating is a bonded film with real thickness, and the difference shows up first under a tire.
What does the topcoat do?
The topcoat is the layer you walk on: it takes the wear, handles the sunlight, locks the flake down, and carries whatever texture the floor has.
What is a concrete floor coating?
A concrete floor coating is a resin system bonded to prepared concrete: a base coat, usually a flake broadcast, and a topcoat that takes the wear.
What is a polyurea floor coating?
Polyurea is a flexible resin used as the base coat in most floor systems, because it soaks into prepared concrete and moves with the slab.
What is the difference between a concrete sealer and a coating?
A sealer soaks into the concrete and leaves it looking like concrete, while a coating builds a film on top and changes the color and the surface.
What is the difference between polyaspartic and epoxy?
Polyaspartic handles sunlight and slab movement better, epoxy goes down harder and more brittle, and which one suits a floor depends on the floor.
Prep and the slab
Grinding, moisture, cracks and old coatings. This is the half that decides whether the rest holds.
Can a new coating go over an old one?
Usually the old coating comes off first, because a new coating is only as attached to the floor as whatever it was put on top of.
Can a pitted or flaking concrete floor be coated?
A pitted or flaking floor can usually be coated once the loose material comes off and the low areas are rebuilt.
Do cracks have to be fixed before a floor is coated?
Cracks get opened up and filled before the coating goes down, and how a crack behaves afterward depends on whether the ground under it is still moving.
How does moisture in a slab affect a floor coating?
Concrete on grade moves water up through itself, and the pressure of that vapor under a coating is what lifts the coating off the slab.
How long does new concrete have to cure before it can be coated?
New concrete has to dry as well as harden, and how long that takes comes down to what the slab reads on a moisture test.
What does the prep involve?
Prep is the room getting cleared, the concrete getting ground open, the damage getting fixed, and the dust getting vacuumed off before anything goes down.
Why does concrete have to be ground before it is coated?
A coating grabs a roughness in the top of the slab rather than a smooth surface, and grinding is what puts that roughness there.
The install
What the days look like, what the weather has to do, and when you get the floor back.
Can a floor be coated in cold weather?
A floor can be coated in cold weather, but what governs it is the temperature of the slab rather than the air, along with the humidity and the dew point.
Does a floor coating smell?
There is an odor while the material goes down and while it cures, and how strong it is depends on the product and on how much air moves through the room.
How long before you can park on a coated floor?
A coated floor comes back to you in stages, walking first and a vehicle last, and the number for your floor is the one to ask for before the work starts.
How long does a floor coating install take?
A coating install runs as a sequence of passes, and what stretches it is what the grinding uncovers rather than the size of the room.
What do I have to do before the crew arrives?
Empty the room down to bare concrete, take anything mounted low off the walls, and have somewhere else for the vehicles to sit.
What happens to the control joints and the saw cuts?
A control joint is where the slab is meant to crack, so it either gets filled and coated over or left as a visible line in the finished floor.
Wear and failure
Peeling, hot tires, yellowing, and what actually shortens the life of a floor.
Do floor coatings turn yellow?
Sunlight ambers some resin chemistries, so a floor shifts color where the light lands, and the top coat is the layer where that difference sits.
How long does a floor coating last?
The service life of a coated floor comes down to the prep under it, how much film went down, and what the floor gets asked to do after that.
Is a coated floor slippery when it is wet?
A smooth top coat with water on it is slick, so texture gets added into the top coat, and how much belongs on your floor depends on the room.
What damages a coated floor?
What damages a coated floor is a small hard foot under a heavy load, dragged steel, heat set down on it, and something spilled and left to sit.
What is hot tire pickup?
Hot tire pickup is a warm tire softening the coating under it and taking some of the film with it, leaving bare patches the shape of the tread.
Why do floor coatings peel?
A coating peels when the bond to the concrete was never made, or when water moving up through the slab breaks that bond from underneath.
Where a coating goes
Garages, basements, patios, pool decks, laundry rooms and shop floors, and what changes room to room.
Can a basement floor be coated?
Yes, and what decides it is what the slab reads for moisture, because a basement floor sits in ground that holds water against the concrete all year.
Can a driveway be coated?
Sometimes, because a driveway takes vehicle weight, plow blades, road salt and a deeper freeze and thaw swing than any other slab you own.
Can a laundry room or utility room floor be coated?
Yes, and most of the work is emptying the room, because the washer and the dryer have to be disconnected and moved before anybody touches the floor.
Can a patio or a porch be coated?
Yes, and an outdoor slab gets judged on three things a garage floor never faces: full sun, the freeze and thaw cycle, and where the water goes.
Can a pool deck be coated?
Yes, and on a pool deck almost the whole decision is texture, because the surface gets walked on wet and barefoot in full sun all summer.
What is different about a shop or commercial floor?
A commercial floor is a working surface, so what rolls across it, what gets spilled on it and how much time the business can give up decide the system.
Living with the floor
Cleaning, road salt, winter meltwater, and what happens when something goes wrong.
Can a coated floor be repaired?
Yes, and what it takes depends on whether the damage is in the top of the film or the coating has let go of the concrete under it.
Does a coated floor make a garage wetter in winter?
It looks wetter because the snow melting off a vehicle stays on the surface instead of soaking into the slab, which is the floor doing what it is for.
Does road salt hurt a coated floor?
On bare concrete road salt soaks in, and on a coated floor it sits on top of the film, so what is left behind is residue to clean up rather than damage.
How do you clean a coated floor?
Most of it is sweeping or a dust mop, and when a coated floor needs more than that it gets cleaned wet rather than scrubbed with anything abrasive.
Getting a number
What moves a price, what a kit is and is not, and what to ask before anybody starts.
Are DIY garage floor kits worth it?
A kit off a shelf and an installed floor differ in the prep more than in the bucket, and the prep is what decides whether a coating stays stuck to concrete.
How do I measure my garage floor?
Measure the concrete rather than the building: wall to wall one way, back wall to the outside edge of the door opening the other, and multiply.
How much does a garage floor coating cost?
A garage floor coating is priced by the square foot of floor, and what moves a quote is the condition of the slab and how much has to come off it first.
What does a floor coating warranty cover?
A floor coating warranty is usually written against the coating letting go of the concrete, and it is usually not written against the concrete itself moving.
What should I ask a floor coating contractor?
Ask how the concrete gets opened up, what happens if the slab reads wet, and what the quote says about the cracks.
Send a photo of the floor
Free estimates across the southwest Twin Cities metro. Tell us what you are looking at and what the room gets used for, and we will tell you what the floor needs, including when the answer is that the concrete comes first.