Interior concrete floors come in many styles and colors. Stamped concrete floors can be made to look like natural stone or scored into squares that resemble porcelain or ceramic tiles. New concrete may be custom colored prior to installation, but surface treatments, such as painting and staining, are options that can be used at any point. Old concrete slabs can be given new life using materials from a home center and techniques that are within the capabilities of most do-it-yourselfers.
Planning interior concrete floors before construction begins affords more options. For example, liquid or powdered colorant may be mixed into the concrete to create even color through the entire slab. After the concrete is poured, and before it hardens, patterns and designs can be stamped into the surface, a technique that can only be employed in new construction. Other surface effects, such as marbling, can be added to the floor after it has cured. Concrete sealant will protect the porous concrete from staining and keep it in good condition.
Paint is one of the easiest and least expensive treatments available for interior concrete floors. New floors can be painted as soon as curing is complete, but older floors must be stripped of floor coverings and any glue or mastic that remains. Specialized solvents and grinding machines are available for cleaning the concrete, which preps it for painting. Although water-based concrete paints are less hassle to use, oil based paint is preferred for its durability. Two coats of sealant helps to add a subtle sheen to the finish and makes it easier to clean and more durable.
Stained interior concrete floors are another attractive option for any home or building. On new concrete, staining can proceed after general cleaning, but older homes or buildings with glue-down flooring must undergo the same type of glue removal necessary to prepare a floor for painting. Two types of stain are available: non-reactive and reactive. Non-reactive stains are water-based acrylic stains that penetrate the concrete surface through its open pores. These stains come in a wider range of colors than reactive stains and are much easier to apply; they produce a uniform, predictable result.
Reactive stains for interior concrete floors are water-based acidic solutions containing metallic salts that react with the lime in the concrete. When this chemical reaction occurs, the stain bonds permanently to the concrete and will not chip or peel. Staining with acid produces unique results on every floor. Colors develop because of the chemical reaction and are somewhat unpredictable except to a trained professional who has learned, from experience, what to expect. Variegated, translucent color in rich shades is characteristic of acid stains and is a dramatic look that is sought after and prized by many.