There are 4 primary products you can use to concrete your garage floor -- polyurea, polyaspartic and 2 types of epoxy. So which is best? Most of these materials have pros and cons in ease of application, adhesion, quality, appearance, durability and cost. The cheapest solution is a DIY epoxy paint from the hardware or big box store. Their instructions just tell you to chemically etch the floor, let it dry and paint it on; just one coat. Rustoleum EpoxyShield is the best known DIY solution. It's water-based and only 55% solids. They dilute the epoxy to help with adhesion, but then you don't get anywhere near the thickness of other solutions. They also miss one very important step in the chemical-etching process. Most of these DIY solutions last a month to a year or even two depending on the prep. If there is a cure and seal sealer on the floor, the epoxy will adhere only to the sealer and not penetrate it.
Grinding is a superior prep method compared to chemical etching and critical to remove previous coatings or sealers. A 3rd method of prep would be a shot blaster, which is also good. Shot blasters will profile the concrete for good adherence, but do not flatten the floor or identify any dips. It does profile dips that a grinder will not do on its own.
Make sure before coating your floor that your contractor fills all the cracks and other damage like spalling, pitting or chipping with an approved product. We use a proprietary quick drying polyurea product that we grind back off smooth to keep the floor flat. You can see some examples in our Job Gallery
Our advice -- keep your options open and compare. We'll help you decide which is best for you in terms of quality, durability and cost. Contact us
for a quote.