ALWAYS PERFORM TEST AREAS. CONCRETE MUST BE DRY. SHAKE OCCASIONALLY DURING APPLICATION TO KEEP COLOR IN SOLUTION
Determine if the concrete is porous with a simple water test. If the water drops in and darkens the concrete immediately, then prep may not be necessary. If the surface is a troweled surface, you may need to mechanically grind, sand, or chemically etch the concrete to open pores for better penetration of the stain. If them is a sealer present and in good condition, you may put a drop of acetone on the surface and rub with your finger to determine if the stain will penetrate when mixed in acetone (surface will get sticky or tacky when you rub, if it can be penetrated with acetone).
Water is not recommended when applying to overlay systems that are commonly high in polymer. The water will often raise the polymers to the surface. Using more than one color will often help to achieve a beautiful mottled look. After the stain is applied there may be residue that can be removed by buffing the floor. If you do not wish to buff the floor, you may want to wear booties to keep from leaving footprints in the residue.
After the stain is dry to touch, seal with Masterpav Endurable Sealer. The concrete should be free from contamination. It is recommended to determine if the concrete needs to be cleaned with a concrete cleaner or pressure washed at approximately 2000psi (If fungus is present in the concrete, you should clean with a fungus killing product and then pressure wash). Use a listed carrying agent.