Does my floor qualify?
Like I’ve said earlier, concrete floors are everywhere. Consequently, they also come in every shape and style (and most importantly, condition) that you can imagine. You’re here because you want to know if your floor is going to be eligible for an acid staining treatment. Well, the easy answer is: you’ll never really know until you at least do a test on a sample of your floor. However, there are many indicators and guidelines that you can use to get a pretty good idea if your floor is going to work.
First of all, you need to examine the physical structure of the floor. Look for problems like major cracking, soft spots, chipping and extremely out of level. Some of these problems can be addressed; some really cannot.
If you had cracking like this, you would want to consider a concrete overlayment. Imagine this slab as a floor and you can see an example of cracking that will not patch properly. Other obvious issues with this particular slab include deterioration and uneveness.
But what if you have some cracking or uneveness or deterioration? All is not lost. See our section on concrete repair. Keep in mind that patched concrete will accept the acid stain differently than the surrounding slab. In fact, any deviation in materials will result in deviations in the stain acceptance and look of the floor. Sometimes that is fine; sometimes it is even great! Sometimes it can ruin a job.
Second, you should consider the location of the floor. Is it indoors or outdoors? Both will work, but you might want to take weather into consideration as you plan the project. Is it above grade or below grade? Moisture is very problematic in below grade concrete floors, but you can successfully acid stain a basement floor.
Third, it is critical that you examine the surface of the concrete. This is where most DIY projects will be vulnerable to failure. Concrete is porous and the acid stain is carried into the concrete by water. It is absolutely imperative that water is able to penetrate the concrete in order for the stain to “take.” Things that reduce (or eliminate) porosity in concrete include: paint, grease, epoxy, bleach, wax, glues, curing agents and dirt, among other things. In addition, a tightly finished slab will also have reduced porosity.
The Porosity Test: How can you tell if your concrete floor will absorb and take the acid stain? One easy DIY method is the simple Porosity Test. All this entails is spraying or sprinkling a little water on a section of the floor. If it beads up you know you have porosity issues. If it quickly soaks in you are good to go. Note the difference between standing water and water that has been absorbed in the picture on the bottom.
If you have porosity issues, you can probably correct them. See our section on surface preparation.
Next: Tools you will need