I was reluctant to try this on my garage floor, which endured thirty years of oil drips and was horrible to behold. The floor was a disaster. It was so bad I wanted to tear it up and pour a new one, but I thought I'd try an epoxy coating thinking that if I didn't like it, I could still tear up the floor. Preparing the floor involved a combination of extensive mechanical scrubbing, pressure washing, various detergents, solvents, acid, sweat, and blood. To make things worse, I didn't want to rinse everything out onto a finished driveway, and had to mop up the effluent rather than just spray it outside. Preparation was a time-consuming, miserable task, but the eventual results are nothing less than spectacular. It's been a year since I finished the job and it has held up well. I can't imagine a more cost effective and beautiful concrete floor covering.
Having read extensively about what this work would entail, I realized that inadequate preparation would guarantee failure. At first I thought pressure washing the floor would remove most of the oily crud. Wrong. I was surprised to determine a 1500 PSI washer was completely ineffective removing thirty years of thick, greasy, dusty crud. I then tried an electric drill with a wire wheel but the pressure required to remove the crud made the drill impossible to control. So, I was left to scrub every single square inch of my oversized three car garage with a wire brush and a metal scraper. I repeatedly filled my dustpan with pounds and pounds of icky black crud. The crud was very difficult to remove. It was a miserable job - several hours a day, every day, for about three weeks. I completely wore out two wire brushes, about an inch of the flexible metal scraper, a lot of skin from my knuckles, and my knees have just begun to recover.
After weeks of this hands-and-knees misery constantly regretting my decision not to bring in a backhoe, or dynamite, I rented a heavy commercial floor scrubber equipped with a wire wheel. This was a great idea - the wire wheel removed even more stuff that I couldn't by hand. The machine felt about as difficult to control as a helicopter but once I got used to it things went OK. I wore off about half of its wire wheel.
After each of the scraping routines, I scrubbed the floor with a hot Lestoil solution which helped remove more of the grease that couldn't be removed mechanically. I did this several times, followed up with the pressure washer, mopping up each time, until I was satisfied the Lestoil would remove no more.
Then, I finally applied the acid etch. It was rather dramatic, fizzing on some stains more enthusiastically than others. The previous owner must have spilled all sorts of interesting stuff in the garage. I repeated the acid etch, rinsing and mopping each time, until I was satisfied it would fizz no more. The acid conspired to dissolve the mop but I was done with it by then.
After several days of letting the bare concrete dry followed by blowing out wire brush pieces and dissolved mop crumbs with a leaf blower and broom, I finally had a floor which bore a slight resemblance to the little garage in the DVD, and was ready to begin the painting part of this painting project. The Quikrete kits contain everything you need, including acid etch concentrate and even a paint stirrer. I had everything masked off and ready to go, the weather was about 70° F and dry. The paint goes on as advertised and there were more than enough flakes. The coverage estimate of 250 square feet was accurate, maybe even conservative, on my less-than-smooth floor. The entire garage took four gallons, and I had a little left over to coat some outdoor concrete patio stones (more on that later). After the misery of preparation the actual coating was easy. At that temperature I had about three hours before the epoxy began to set. You'll probably want to throw out your paint roller frame when you're done, and don't even try to clean the roller cover. Same with the brushes for cutting in - buy cheap brushes and throw them away.
I let the epoxy cure for about three days, much more than Quikrete specifies. I didn't want to take any chances!
After all this, the clear coat was comic relief to apply. It ought not to be considered optional - most of the flakes will stick to the base coat, but it's inevitable that some will crack when walking on them and you'll track them all over the place. Lighter colored paint and flakes will also get dirty very quickly, so be sure to include the cost of clear coat in your finishing project. If I had to do it over again I might have applied two coats of clear. It results in a beautiful shiny finish, but two coats may have resulted in a more uniform appearance. Quikrete claims coverage of 500 square feet which is again on the conservative side. It was simple to apply, but there's one thing they don't tell you - it will yellow considerably if applied in direct sunlight. After it cures, it may still yellow slightly in direct sunlight but the effect is minimal. Quikrete ought to make this known, or include some sort of UV protection. Don't forget to stir in the anti-slip granules - they're plastic beads that remain nicely suspended in the paint and are included in the clear coat kit. Omitting these will result in a very slippery floor.
So, after a year of car, foot, bicycle and Rollerblade traffic, the results are just spectacular. The floor cleans as easily as a countertop. No matter how much you sweep or clean a bare concrete floor, you'll pick up little bits of dirt that works its way into your house. Now, I want to take my shoes off before walking in the garage. It's that nice. The unexpected part is the patio stones - even though I didn't prepare them at all, the coating remains beautiful despite being placed on top of dirt and are constantly out in the weather. None of the coating has flaked off. Same with a piece of wood I treated just as an experiment - the coating looks just as nice as the garage floor despite being out exposed to the weather for a year.
I liked the result so much that I coated my entire basement floor, which was much easier since I didn't have the oil stains to contend with. All told I purchased eight garage floor coating kits plus another four of clear coat, at a total cost of well under $1000 including materials and equipment. The garage and basement are beautiful.
If your floor is clean, this is a no-brainer. There is no better concrete floor covering at this cost per square foot. If your floor is a disaster like mine, be prepared to put the same effort into preparation as I did, since paying someone else to do it for you is likely to be prohibitively expensive. Either way you should be pleased with the results.