Ottawa's MyMason.ca: About Cement & Concrete Colour Dyes:


Surface colouring techniques - excluding acid stain, are applied to cement or concrete topically to add color or shift an existing colour.

Dyes applied wit solvents result in one color throughout, while acid stain chemically reacts to present a range of tones of the colour,

Dyes are in their natural, concentrated, powder state or are blended with either alcohol or solvents including water. The solutions react differently: a water-based solution evaporates slowly and so pooling and puddling can occur - even desirably. Acetone dries very fast therefore the color will 'flash off,' without pooling or puddling. Other solvents are in between.

Sunlight and the salts used in Canadian winters may fade cement colours. Sealers can be used to address this.

Prep: Thoroughly clean the surface. This can be done with a non-residue cleaner and a stiff bristle brush. Avoid wire bristles, since these can damage the surface of the concrete, making acid stains take unevenly. Use a degreaser to remove grease spots and scrub until the spots are gone. Adhesives and paint spots can be effectively removed with paint thinner.

After using these cleaning substances, it is important to rinse the area thoroughly with a garden hose. You can also use a power washer to make sure every speck of debris and dirt is removed before the staining process commences. Once your concrete surface is completely clean, allow it to dry thoroughly before staining. This may take a day or two, depending on the weather conditions.

Concrete stain is similar to wood stain but can actually highlight and intensify the variations found in the concrete. This includes natural as well as man-made blemishes and markings.

Acid stains react differently to each type of surface to which they are applied - so it is imperative that a sample is done on the actual concrete or surface that is going to receive the treatment.

Potential Problem: Too little product won't give complete coverage, nor will it etch the surface sufficiently to deeply deposit the color. Too much product on the other hand can cause unwanted puddling and pooling and over react the areas where it has pooled on the surface. Then there is the scrubbing method. If scrubbing isn't done with a natural flow and pattern, mop lines and obvious swirls may appear.

Once the concrete is sufficiently dry a sealant of coating should be applied.

Even if you hire the best acid stain concrete contractor in your area, their abilities will depend on the surface on which you give them to work with. It may not be possible to completely hide and blend-in the color with a badly stained and damaged concrete slab.