What a kit actually includes
A hardware-store kit gives you resin, a little etching solution, and decorative chips. It does not include a diamond grinder, a moisture test, crack filler, or the experience to read a slab. The kit is maybe a third of a real job — the other two-thirds are prep and equipment.
Where DIY goes wrong
Most DIY failures follow the same script: etch instead of grind, coat over invisible moisture, park on it too soon. The floor looks great for a few months, then peels in sheets where the tires sit. Fixing a failed DIY floor costs more than doing it right once — the old coating has to be ground off first.
When DIY makes sense
Fairness matters: a kit can work on a small, new, dry slab with light duty — a laundry room, say — if you follow the cure times exactly. Low stakes, small space, and you accept it may need redoing in a few years.
When to call a pro
Garages with old oil stains, any slab with moisture history, large areas, and anywhere a failure would be expensive to fix. A pro brings the grinder, the testing, and a system designed for your slab — plus a free written estimate up front so you know the real number before you decide.