I really debated posting this one…
The topic of acid staining concrete floors strays a little from my usual subject-matter and seems slightly more suited for a home renovation blog. But I decided to go for it anyway, as I figured a) I have a ton of very thrifty, very handy readers who love frugal, DIY stuff, and b) I honestly just wanted a reference for myself, as I have a bad habit of doing a complex project and then promptly forgetting all the details for time and eternity. Ahem.
So here we are.
To catch up those who may be new to the Prairie Homestead craziness, we did a massive home remodel last year (basically building a whole new house onto our little shack), and added a full basement in the process. (Previously we had a teeny tiny hand-dug basement resembling something out of a horror movie.)
We had the new basement sheetrocked with the rest of the addition, but I put the rest of it on the back burner as 2016 had us occupied with other projects. So when I found myself with an unusually quiet week between Christmas and New Years, and decided it was time to wrap up this basement once and for all.
I rushed to acid stain the concrete in the guest room downstairs earlier this year as we had a steady string of house guests coming through and they needed a place to sleep (funny how that works). Doing that smaller room first gave me a good chance to experiment with the acid staining process (for some reason, it felt extremely intimidating to me when I first started researching it). And true to my nature, I messed up my first go-round a bit, so I’m glad I had a chance to make adjustments before finishing the rest of the rooms.
But before I go into the specifics (and my mistakes), let’s talk about why we chose acid stain concrete in the first place:
Why We Chose to Acid Stain Our Concrete Floor
1. It’s not carpet. I have a passionate hatred for carpet, y’all. We have carpet in two small bedrooms in our house and that is IT. Dogs + 3 kids + a rural lifestyle = disgustingly putrid carpet. I just couldn’t stand the thought of putting pretty, fluffy carpet downstairs so the dogs could throw up on it, poop on it, and the kids could spill stickiness all over it. Nope. Not gonna happen.
2. It’s cheap. But not tacky-cheap, or fall-apart-in-18-months cheap. Since carpet was obviously out of the question, we priced wood for the large room (ouch) and tile (bigger ouch) and decided the price wasn’t something we wanted to pay.
3. It’s tough. Since the acid stain actually reacts with the concrete itself, it won’t scratch or peel like paint.
4. You can always cover it up. If I suddenly develop an affinity for carpet in 3 years (ain’t gonna happen, but still….) we can just slap it over the top of the concrete– no big deal. Same goes for other floor coverings.
5. It looks darn cool. Acid stained concrete has the rustic, irregular look I love, and I see it going with a variety of styles and designs. It works with the natural irregularities of the concrete to create a rich, marbled look. No two floors will look the same.
Will MY Concrete Floor Work for This?
To be perfectly honest? I have no idea. I am not claiming to be the definitive acid-stained concrete expert in any way, shape, or form. Since this is a considerable project with pretty permanent results, you’ll want to spend time doing your own research and to decide if this will fit your situation. I read DOZENS of articles on acid staining concrete before I even bought my supplies and I suggest you do the same. Here are a few I found helpful:
We didn’t intend on acid staining our concrete when the floor was poured, so we didn’t have the concrete crew take any special considerations. They power troweled it, and we slopped paint and sheet rock mud on it as we were finishing the walls (which I deeply regretted later….). However, the stain still reacted beautifully with the concrete once I cleaned it.
The biggest consideration is the floor with which you’re starting. This is a stain, not a paint. It’s not covering anything, but rather reacting with the chemicals in the concrete. Therefore, you want to make sure the floor is EXTREMELY clean before you start. Any sort of paint or glue residue can mess up the stain reaction. Your best bet is testing a small area of your concrete floor to make sure the acid stain works properly before committing to the whole thing.
Equipment & Supplies for Acid Staining
In the grand scheme of things, this is a pretty low-budget DIY project. However, there are a few tools that’ll make your life much easier:
A Shop Vac: It is VITAL all residue is completely gone from the floor before you apply the stain and sealer. That’s pretty tough to do with a regular ol’ mop, so we relied on the shop vac to suck all the nasty water off the floor.
Scrub Brushes: I had a very stiff hand-held brush, along with another brush with a long handle. Both were crucial in the cleaning process.
Squeegee: You could do the project with a squeegee, sure… But it sure made things easier during the cleaning. I used it to scrape the rinse water towards my shop vac.
Floor Cleaner: If your floor is very dirty, you’ll want a heavy-duty cleaner that won’t leave a residue. TSP is what is recommended by most professionals. I couldn’t find TSP locally, but I did find a TSP-alternative that worked just fine for removing the paint residue on my floor. (I think it was a better option, anyway– TSP is rather nasty I think.)
Sprayer: I wanted to use an old weed sprayer for this, but the only weed sprayer I have has metal parts inside the sprayer assembly. You cannot use a sprayer with ANY sort of metal, as the metal will create a nasty reaction with the acid stain. So I just used an all-plastic, quart-size spray bottle instead. Yes, my hand got tired, but it still worked. (And I did’t feel as bad about just tossing it when the project was done.)
Protective Gear: Rubber gloves are a must, and a mask and eye protection isn’t a bad idea, either. The stain can burn your lungs if you breathe it in, so good ventilation is wise.
Acid Stain: There are a bunch of different brands out there, but this is the one I went with from Amazon (affiliate link). The color I chose is dark coffee-brown with some slight reddish undertones. I used just under 2 gallons for a bedroom, storage room, and the large family room. You’ll want to check the manufacturer recommendations on the stain you’re using to see how much you’ll need for your space.
Clear Concrete Sealer: I found the Clarishield Wet-Look Water-Based Sealer at Sherwin Williams and went with that. I know there are a variety of other products that’ll work for this, too.
How to Acid Stain Concrete
{Step One} Prep
When I did my first room, I decided to be lazy and NOT mask the bottoms of the walls. My big idea was to use a foam brush to apply the stain around the edges of the room, and then follow up with a sprayer in the middle areas. I figured I wouldn’t have the danger of overspray on the walls and I could skip the masking.
And… this was a horrible idea. The stain applied with the foam brush ended up being much lighter than the stain applied with the sprayer…. So that room is rather blotchy and uneven. Not the end of the world I guess, but needless to say, I masked the next two rooms, used the sprayer on the whole thing, and the results are much better.
So yeah, masking is a good thing.
{Step Two} Clean
I can’t stress enough how important this step is– do NOT skip it and do NOT skimp on it. You’ll want all paints, dirt, grime, and glues completely removed from the floor before you get started. Admittedly, this is also the least fun part of the process….
We had some pretty thick paint overspray around the edges of our walls. My cleaner wouldn’t remove it on its own, so I had to use a sharp scraper to peel it off the floor. I then followed it up with a hard scrubbing with water and cleaner. In my first room, I used a gel paint stripper to loosen the worst paint overspray on the edge of the room, and I wish I hadn’t. It seemed as though the paint stripper changed the concrete a bit and it caused the stain color to be different where the stripper had been used.
My cleaning routine was: scraping paint/gunk off the floor, scrubbing with warm water and the TSP-alternative, vacuuming up the water, rinsing with fresh water, and then vacuuming again. Yep– it was super tedious.
I did this 2-3 times until the floor was as clean as it possibly could be and there wasn’t any dirty water left anywhere on the floor.
{Step Three} Stain
One the floor is completely clear and dry, it’s time to break out the stain. Give yourself a full day to do this portion of the project. Not because you’ll need to be working the entire time, but rather because you’ll need to stain, wait a couple hours, and then neutralize the acid. There’s really no way to know exactly how long the stain will need to sit on the floor before it’s ready to neutralize, so you want to have plenty of time to be flexible. (However, 2-4 hours is a pretty average time frame. I left my stain on for about 2 hours before I started neutralizing.)
Put on your protective gear, and fill your sprayer with stain. Some websites advised diluting the stain with water, but I didn’t.
Pick a corner and start spraying. Try to keep the spray in an even layer as you go, but remember it doesn’t have to be perfect ( that’s why I love this project so much). Once you get in your groove, it really doesn’t take long to spray an entire room.
When the spray first goes down on the floor, it’s super light. Mine was approximately the color of bile when it first hit the floor (I had a small heart attack at that point), but don’t worry–it’ll darken as it sits. It also might fizz a bit, and that’s normal too.
Work over the entire room, then allow the stain to sit on the floor. As dries, it will darken and then turn super chalky and quite ugly. (Another heart attack, but it’s OK…)
The next part is up to you– you will need to watch the floor and see if you like the shade of the stain. Mine darkened to my ideal shade after about two hours, but your floor may take more or less time. You might even need to apply another coat after a couple hours, (but I didn’t).
{Step Four} Neutralize
It might seem weird to scrub a floor you just spend an hour coloring, but this step is important to remove any leftover acid residue which may cause problems when you go to seal the floor. Once the floor is dark enough for you, use a mop and/or scrub brush to scrub it with an ammonia/water solution. (I used about a cup of ammonia to a gallon of water.) I did one application of the ammonia & water, and then rinsed it 2-3 times with fresh water until my rinse water was mostly clear. Again, tedious but necessary. (My shop vac/squeegee method was handy here, too.)
Let it dry complete (at least 24 hours) and then you’re ready for the last step!
{Step Five} Seal
Not only does applying a clear coat to the floor protect it, but it also gives it that “wet look” and brings out the beauty of the stain.
I applied my clear coat with a roller with a long handle. The smoother the roller nap, the better. (I used a 3/8 nap roller on one of my rooms (it was all I had), and I didn’t like the “texture” it left in the finish. A smoother nap would have been much better.)
Make smooth strokes with the roller, and try not to “overwork” the clear coat. I applied two coats to mine. My sealer looked white and milky when I first applied it, but then dried to a clear finish.
Let it dry, and you’re done! I plan to wax my acid stain concrete for extra shine and protection, too, but haven’t found an appropriate wax yet– I’ll update this post when I do.
