Wednesday, June 13, 2012

Ups and Downs of Staining Concrete

Since before we poured the first floor concrete I started experimenting with stain for the final concrete floor. I practiced on the crawl space floor, the foundation wall, the old slab in front of the workshop, pretty much any concrete I could get near got a taste of my staining expertise, or lack thereof.

After a little research I found out that you can use iron sulfate to stain concrete. Iron sulfate is common in a lot of garden fertilizers and even warns on the bag - "will stain concrete". YEH! That is what we want.

So I found a few different types at various local gardening stores that were 19% sulfur and 33% iron, the recommended amounts for success. Here and here are where I got inspiration from.

Fertilizer in hand I was sure I would end up with stunning floors. You know something that looks like this.

Umber stain, photo via

Well, I followed the instructions from the blogs and tried a few test areas. Not seeing any immediate results a changed the process up a bit and tried a few different ways. The center section below is an example of what I got.

Yeh, Nothing, Nada, Zilch, Nill, Naught, Zero. Ughhhh, I knew it was too good to be true. Fortunately the fertilizer is pretty inexpensive and I can use it in parts of the garden so not all is lost. 

The sections on either side of the disastrous fertilizer experiment were done using Brickform. We picked up a couple of samples the last time we were at Cemex, yes, like Home Depot, it is a regular destination (Kyle knows how to show me a good time). I applied the samples a few different ways, sprayed it on, painted it on with a paintbrush and poured it on and spread it with a rag. What you use to apply it is critical, you can see the lines here where I used a paintbrush, No Go. It was not a good look. I didn't really like the colors either, they came out a bit orange looking. 

A few years ago I fell in love with Kemiko floors but had forgotten about them till I was doing more research on acid stain for concrete. Still madly in love with these floors I ordered a few samples and when they poured the concrete floors downstairs Kyle had them pour a few little samples that we could use to test the new stains.

This one is Malay Tan. It could ideally use another coat but it is quite light in real life. This picture doesn't really help the true the shade but it is not a deep, warm color we were looking for.

This one is Cola, and on the Kemiko website it comes across as pretty dark but our sample didn't turn out that dark. This one has two coats on already. In real life it has a lot of green in it but it is not bad.

This one is Umber and is the WINNER, ding, ding, ding. It is two coats pretty straight and is just the leathery look that we want. I knew it was a keeper when Kyle walked up and just said "that is IT". It is gorgeous in real life, deep, rich color and just mottled enough. 

There will be a lot of variation when applied to the entire floor as the acid reacts differently with the concrete depending on how the concrete makeup varies. If there is more lime in one area the color will be slightly different than other areas but that is the beautiful irregular look we want. Sort of like this-

Photo source -

Check out HERE for more pics of different stains...they are stunning. Of course the au natural look is also my favorite - like what Marti did on her floors at the 8747 House.

Well in the midst of installing poop pipes and miles of pex tubing it is fun to think about something finished and pretty. Back to figuring out how to vent the kitchen sink.....oh the life:-)


  1. Love this color. Will you give it a high gloss finish like the picture? That floor is gorgeous.

    1. Probably go with the type of sealer in the first picture from Though the "wet" look is really nice too.

  2. I've been thinking about doing a concrete acid stain on my driveway. Thanks for the post. It was just what I was looking for!

    1. Thanks for that link, I will have to check out their products too. I think it is one of those processes that you just have to leap into and have fun with. Hope your driveway turns out great!