Painting a Concrete Shop Floor
Advice on cleaning and applying a rugged coating to a shop floor. March 4, 2006
I just bought a shop that used to be a taxidermy shop. You can imagine the mess on the floor. I have been considering painting the concrete floor but wanted to get some input before I proceeded. Any advice on this matter would be appreciated.
From contributor A:
If it is possible I would power wash the floor first .If not there are products at your local Home Depot or Lowes that will clean the floors as well as products made to paint concrete floors. I don't think you'll be sorry you did this.
From contributor B:
Painting a concrete floor is the biggest potential problem in the painting industry. I should know - I run a commercial painting company. First, you must determine what is on the existing floor - bare concrete, sealed concrete or painted concrete. If bare, you must acid etch the floor. This will give the floor a profile that the paint can bite into, like 180 grit sandpaper. This does not address grease or oils on the floor. They make an emulsifier to address this concern. A sealed or painted floor must be abraded or scarified. You can use a sanding pole for a simple solution. Once the floor is prepped then you must decide on a finish. I recommend Sherwin Williams Epolon Multimil. It is a low sheen epoxy, which will make it durable but not slippery. One last thing - if you will be using an epoxy, you must be sure it is compatible with the existing floor system. If using the product I recommended, get a pint of Goof Off. It is a solvent that's sold in any paint store to remove dried paint. Put some on a q-tip and rub it on the existing finish. If it softens the finish you cannot put a solvent based epoxy on without a primer.
From contributor C:
I've finished my floor just this week. It was fairly clean - first I mopped on muriatic acid then rinsed. I used it full strength but it probably can be diluted. It turned out great but I used a grey stain, not paint. I did this once in an employee breakroom, the same way, and it lasted for years. Roll the stain on with roller with an extended handle - out of a paint tray. Roll on well, just as painting a wall. Pay closer attention to any real greasy areas and maybe first wash the very worst areas with dish cleaner and hot water. Some areas may need scraping. Don’t sweat it too much. Acid not really dangerous at all – just make sure you read the directions. The floor must be real dry before stain and don’t do it on a rainy day.
From contributor D:
I recommend an epoxy floor coating, like used in commercial garages. It comes in light base colors to which sprinkles can be added for looks. Just pour and spread - it's self-leveling. Floor "slickness" is up to you, but the basic coat is slick enough to easily sweep, but not so much to be hazardous. Once cured, this coating will stand up to years of abuse and many chemicals and the manufacture claims to add some cushion to the floor making it easier on your back and feet. Cost is about $500/5 gal pail which I believe covers about 1,200 sq ft. If this something you're interested in, do a google under "concrete floor coatings". Either way, I'd prep it the way contributor B suggested.
From contributor E:
All good suggestions, though some of the expense may scare you into trying plain old deck or porch paint as I once did. It's cheap and holds up OK but even a few drops of a solvent, like our beloved lacquer thinner, turns it into goo. Go with epoxy or something similar.
From contributor F:
It depends on how pretty you want it. I've rolled grey colored leftover conversion varnish on a concrete floor with little prep other than a vacuuming and a wash with thinner. It lasted a surprisingly long time. Do be sure you have a respirator and the exhaust fans running when you do this - and no smoking.
From contributor G:
Rent a high pressure washer with sand pick up. You will clean the floor and the sand will abrade the surface some, it will look link new and be non slick. Also you will save the cost of paint and the labor to re-apply it when it wears out.
From the original questioner:
Thanks for all of the input. I think I will first try pressure washing. If that does not work I am going to go ahead and paint or epoxy.