Stain for Concrete and Stone

Material Cleanliness

• Before staining natural stone and concrete, the surface must be completely clean of debris to allow the stain to soak into the porous surface of the material. Scrub the surfaces clean by hand to remove dirt, debris, mold and mildew; but the best option if you have the space and it is an outdoor surface, is to use a power washer to blast the surface clean. If not, do it the old-fashioned way, with a scrub brush and plenty of physical effort. After cleaning, allow at least 72 hours for the surface to dry before applying stain.

Curing for Concrete

• If you ask 100 professionals, you will receive 100 different answers as to the best time to stain concrete. However, one truth is this: The sooner after the concrete pad is poured, the richer the color the stain will be. This is because the concrete is very wet during the initial curing stages -- which takes up to a month or two to complete -- and the chemical reactions going on within the concrete during this time enhance and intensify the color of any stain applied. However, the downside is this very same moisture works against you, since different patches of concrete cure at different stages, which leads to patchy stain. For richer colors, stain early. For even stain coverage, stain at least a month or two after the pad has been poured.

Layers

• Regardless if you are working on concrete or stone, the more coats of stain you apply, the darker the coverage is. For this reason, always test an out-of-the-way area first, or a scrap piece of stone/concrete to see how your particular stain dries. Always start with a shade of stain a layer or two lighter than what you want the finish coat to look like, because while you can darken a surface through additional layers of stain, you can never lighten the layers. Avoid costly mistakes by working with lighter colors, and gradually build up through layers of stain to achieve your final result.

Application

• Application depends on the type of surface with which you are working. If there are no grout joints to worry about, spraying the stain on with a mechanical sprayer is the fastest method. A paint roller works great on flat concrete pads. Natural stone installations with grout joints, on the other hand, benefit the most from hand application with a paintbrush, to avoid staining the grout joints while at the same time coloring the surface of the stone. For drying times, refer to manufacturer guidelines, and add extra time if the weather is humid.