Outlined below are commonly asked questions about colored concrete. If your question isn’t answered here, give us a call, send us an email or go to Sullivan’s Corner for additional technical expert advice. The information provided is for informational purposes only. This content is not intended to be a substitute for professional advice.

 


Q. Does colored concrete fade?

A. The color can’t fade, but the concrete can. The active ingredient in colored concrete is pure inorganic pigment which is made in a process of oxidizing metal, in essence, “fading” metal into a pigment powder. The resulting powder pigment concentrate is impossible to fade. Concrete, on the other hand does change with time and weather exposure. Even uncolored concrete which turns yellow, erodes and darkens as it accumulates dirt, dust and grime from the environment. Left unprotected or weakened by a poor mix design or finishing job, the surface of concrete “dusts” and erodes slowly until fine aggregate and sand particles are exposed. This same process occurs in colored concrete. The solution is to buy concrete from a supplier who offers mixes designed for durability and an installer with experience in finishing “architectural” concrete. Then keep colored concrete fresh looking by protecting it with periodic applications of a good clear sealer.


Q. Where can I get colored concrete?

A. If you’re a homeowner, the best place to start is with the yellow pages or a local newspaper. Look for Concrete contractors, Landscape contractors or call your local Ready-Mix concrete supplier and ask for the name of a good concrete contractor. If you’re an architect, just specify the Product Color you want in plans or specifications.


Q. How much does color add to concrete cost?

A. Approximately 10 to 30% to the cost of the concrete itself. But it only adds a fraction to the total installed cost, since most colored concrete is mixed and finished in the same way as uncolored concrete. The answer depends on the color you choose and whether you take advantage of all the unique finishes and textures that skilled contractors are capable of.


Q. My new colored concrete is much darker than your color card. Why is that?

A. Fresh concrete is always much darker than when it is fully cured and dry. Even uncolored concrete. Wait at least 7 to 10 days until the new concrete has hardened and dried. If the concrete is on a wet subgrade or there’s underground water, it may stay dark for as long as it’s wet.


Q. Why does my colored concrete have much darker spots than other areas?

A. If the concrete is new, that is less than two weeks old, it could still be drying. However, if some of the dark spots seem to be staying dark while the rest of the concrete is drying out, you may have areas of “Entrapped Moisture”. Entrapped moisture is a condition that appears as random dark areas which can be completely different in shad from unaffected areas. It may also precisely follow areas that were “hard troweled” or where edging and jointing tools were used. Remedy entrapped moisture by scrubbing the dark spots with a stiff bristle brush and flushing with water. Repeat the process over a few days and they should lighten up. If your concrete is older than two weeks, wet the dark spots with water, then pour on some white vinegar and scrub with the stiff brush. Entrapped moisture takes a few treatments to disappear.


Q. Do I need to apply a sealer?

A. Not necessarily. Colored concrete will get good and hard just like normal concrete. However, all concrete benefits from being sealed against stains and water damage. So even though it’s not necessary, sealing your colored concrete will make it look good longer and will help prevent dusting of the surface.


Q. Can you guarantee the final color will match the color card?

A. Unfortunately, Not. The final color is a function of the cement color, sand color, the amount of water used as well as finishing methods. We only guarantee that our color additives will match our standard, that is, they will be the same from batch-to-batch and year-to-year.


Q. What Does Sack Content Or 5-sack Mean?

A. Sack content/mix is specified when ordering concrete, the amount of 94 lb sacks of cement in a cubic yard of concrete. Concrete is typically referred to as a 5-sack mix (or 5-1/2-sack, 6-sack etc.).


Q. What Are The Advantages Of Dust On Colors And In The Mix Colors?

A. Dust on color, also known as color hardener, offers several advantages over integral color. While some contractors use integral color because it is easy to use, the colors are limited. Using color hardener produces a stronger, brighter, more durable and uniform concrete surface compared to integral color.


Q. What Is Color Hardener?

A. Color hardener is used to add a dense layer of vibrant color into the surface of freshly placed concrete. The use of color hardener forms a long lasting color that can be more uniform, repeatable and is more abrasion and impact resistant than integral color.


Q. What Is Release Powder?

A. Release powder is a dry pigmented powder that allows the clean release of stamping tools, while at the same time creates a highlighting color (also known as an antiquing effect).


Q. What Are My Options For Coloring Existing Gray Concrete?

A. There are generally two different types of stain for existing concrete: Water based stain and acid chemical stain. There are several brands and a wide variety of colors available.


Q. What Types Of Concrete Stain Are Available?

A. There are basically two types of stain available, reactive and nonreactive. The reactive (also called acid stain) consists of an acid and water solution mixed with metallic salts that react with the lime in the concrete. This chemical reaction forms a bond with the top layer of the concrete creating the color of your choosing. Acid stained concrete has a marbled translucent finish that some call an old world effect. Since the color comes from a chemical reaction and there is a finite amount of chemicals you are limited to about eight colors per manufacture.

There are a few types of nonreactive stain on the market today, all of which consist of water, pigment and some kind of binder like an acrylic or polymer. Water based stains can mimic an acid stain effect, or be opaque to completely change the color of your concrete. Color choices range from bright to subdued colors or opalescent, even metallics. With layering techniques the color pallet is nearly unlimited, it is easy to see why water based stains have been gaining in popularity.