Stained Concrete Frequently Asked Questions

Question:  I went to my local hardware store and the salesman said to wash my concrete with muriatic acid. It removed the glue but when I went to stain the floor I did not get a color reaction. What happened? 

 NEVER wash the concrete surface with muriatic acid if you plan on acid staining the concrete slab.  The muriatic acid will deplete the lime in the concrete and will roughen up the surface.  The Kemiko Stone Tone Acid stain needs to react with the lime in the concrete and if that is removed, the stain will not color the concrete. 

Question:  Do I have to use the product mixed 1:1 with water?  Can I adjust the dilution rate?

 Kemiko Stone Tone Acid Stain is a concentrated stain that will achieve colors close to our color chart on most concrete surfaces mixed at the 1:1 water to stain ratio.  You should always do a color sample since all concrete surfaces are different and each slab’s reaction to the stain is different.  You can take the stain and apply to one concrete surface and use the same stain and apply to a second concrete surface and you will get two different reactions. To get a lighter color you can add more water and to get a darker color you can add more stain.  This is why color sampling is important. 

Question:  My stain is not getting a reaction with the concrete, Why? 

 This issue can be caused by various reasons. These reasons vary from how smooth or tight the surface is troweled to something spilled onto the concrete. Does the concrete contain add mixtures that were added to the concrete mix like fly-ash or slag?  Was a curing sealant added to the surface to help in the curing of the concrete surface?   All of these issues can have an effect on the concrete accepting the stain.  To find out if the surface is too smooth you can spray water on top of the surface.  If the water soaks into the concrete, the stain will most likely do the same.  If  it “beads” up on top, the stain will “bead” up also and will not penetrate the surface and react with the lime in the concrete.  This can usually be fixed by sanding the surface of the concrete with a sanding screen, black pad (sometimes), or 100 to 120 grit sandpaper. This same technique can work to remove the cure and seal.  To find out if sanding or abrading the surface will help, try sanding a small section by hand, and see if the pores open up and accepts the stain.  Do this in the most unnoticeable area of the floor, since it will be hard to blend that test area in with the rest of the stain process. 

Question: How much does the gallon of stain cover? 

 This product is mixed 1:1 water to stain and will cover approximately 400 sq. ft. in 2 coats or 800 sq. ft. 1 coat.  It is recommended to apply the stain with 2 coats. 

Question:  I like the color that I achieved with the staining process, but there is a small section that did not stain. How can I fix this? 

  This can be caused by something that was spilled onto the floor by the builders or previous owner and can be fixed with a couple of techniques.  Try to brush the stain into the area with a nylon or a chip paint brush first at 1:1 with water and if that does not work try using the stain full strength.  Sometimes sanding the floor with 100 grit sandpaper will open up the pores of the concrete and allow the stain to react.  If the stain just will not get a reaction with the concrete you can try using Kemiko concrete dyes.  The dyes are available in both solvent based and water based systems. Both can be applied to the surface after the reactive stain has been cleaned and neutralized.  After  step 3 has been completed and the surface is dry apply the Kemiko concrete dye to the surface and let dry. After the desired color is achieved, let dry the recommended time and apply your sealer of choice.  When using the dyes, there is no need to neutralize after application. 

Question:  I used your stain and my floor has turned orange and I am using Golden Wheat. What happened? 

Concrete has a bit of calcium chloride in the mix and higher concentrations of the calcium chloride causes the stain to turn the color a deep red or bright orange color.  With this in mind, it is very important to do color sampling before you start your project. To do color sampling, find an area of the concrete that is going to be stained that will not be seen or will be covered up, either in a closet, under some stairs, utility room, or even where you will be putting cabinets or washer/dryer.  

If you notice that the concrete is turning orange or deep red and that is not your desired color, you can add up to 10%, of the total mix with the color “Green Lawn” to that mix.  This will soften the orange or redness created by the calcium chloride.  It may not entirely stop the orange from appearing, but it will knock it down a bit.  If you have already stained your floor and the color turned orange, you can take the color Green Lawn and dilute it down at a ratio of 10:1 (10 parts water to one part stain), and then mist this on top of the stained floor.  This will soften the orange color of the floor.  It may not remove it entirely, but it will put a haze on the floor and the color will soften.  This must be done before any sealer is added to the floor. 

Question: I stained my floor two years ago and want to change the color. How can I do this? 

 This can be done by removing the sealer and applying more stain to the floor. You can only make the floor a darker color, not a lighter color.  One can apply a micro-topping (a thin layer of modified concrete) to the surface and start over.  This will allow for a new color to be applied to the floor. Micro-toppings are an easy way to prepare a floor surface for concrete staining that normally would not accept a stain.