Concrete Prep
Why Does Concrete Prep Matter More Than the Coating Itself?
Most garage floor coatings that fail didn't fail because of a bad product. They failed because the concrete underneath wasn't ready for it. Coating over dust, sealers, or a moisture problem is the single most common reason a floor peels within the first year or two.
Diamond Grinding, Not Acid Etching
A lot of DIY kits and lower-cost crews still use acid etching to prep concrete. It's fast and cheap, but it only opens the surface a little, and it doesn't remove existing sealers, oil staining, or the thin cream layer that forms on top of poured concrete. Diamond grinding with a floor grinder actually profiles the surface at a mechanical level, giving the coating something real to bond to. The industry standard for this is the International Concrete Repair Institute's Guideline 310.2R, which grades concrete surface texture on a scale from CSP 1 (nearly smooth) to CSP 10 (heavily grooved). Most epoxy and polyaspartic garage systems call for a CSP 3 to CSP 5 profile, something acid etching typically can't produce on its own. This is the difference between a floor that lasts 10 to 20 years and one that starts lifting at the edges within 18 months.
Why Moisture Testing Comes First
Concrete is porous, and moisture moves through it from the ground up, especially on a slab poured directly on soil, which is how nearly every garage in Lewisville is built. If moisture vapor is coming up through the slab and a coating goes down anyway, that moisture has nowhere to go. It builds up underneath the coating and eventually pushes it loose, usually showing up as bubbling or delamination. The two standard tests are a calcium chloride test (ASTM F1869) or an in-situ relative humidity probe test (ASTM F2170), and the result tells us whether the slab needs a moisture-mitigating primer first. Skipping this step is one of the most common reasons for early coating failure, and it's invisible until the floor starts failing.
Signs You Can Check Yourself Before Calling Anyone
You don't need a meter to get a rough sense of whether your slab has a moisture problem. Two things are worth looking for on bare concrete before it's ever coated: efflorescence, a white or grayish powdery residue that forms when moisture carries salts up through the concrete and leaves them on the surface as it evaporates, and dark, damp-looking patches that don't dry out even during a stretch of dry weather. Neither one guarantees a problem on its own, and neither replaces an actual moisture test, but if you see either one, it's worth mentioning to whoever quotes the job so they know to test carefully before recommending a system.
Concrete Strength and Age
Concrete strength is measured in PSI (pounds per square inch), and most residential slabs run in the 2,500 to 4,000 PSI range. Lower-strength or older, more porous concrete needs more prep work and sometimes a different primer system to hold a coating properly. New construction concrete also needs to cure for at least 28 days, and ideally longer, before any coating goes down. Coating too early traps moisture that hasn't fully evaporated yet.
Cracks and Expansion Joints
Garage slabs move slightly with temperature and moisture changes, especially with the clay soil common around Lewisville. Expansion joints are built into the concrete to control where that movement happens. A coating that doesn't account for those joints, or that tries to bridge a structural crack instead of routing and filling it properly, will crack again in the same spot. Minor hairline cracks can typically be filled and coated over without issue. Larger or shifting cracks need to be addressed structurally first.
