Even the best laid plans run afoul. Due to mixing and application mistakes, faulty materials, poor planning, or just bad luck, it is always possible that something can go wrong and negatively impact the color on a project. With something as fundamental as integral color, your first instinct may be to tear out and start again. Fortunately, that’s seldom necessary.
As with most things, the first step is to figure out what went wrong. Only then can you appropriately repair the color. Here a few common problems and their fixes:
White deposits form on the surface of the concrete. It is typically caused by jobsite water addition, environmental water, calcium chloride, or subgrade contamination. For mild cases of efflorescence, scrub the surface with a mild detergent. If that does not work or the efflorescence is more severe, sandblast or acid etch the concrete to remove the contamination. Always neutralize and seal the concrete after the efflorescence has been removed.
Light or Bleached Color
Uneven color, with lighter or bleached areas, often indicates entrapped moisture. This can be caused by any number of factors – finishing technique, environmental moisture, “blessing” the surface with water – that increase water content in the concrete. You may be able to simply wait the problem out by allowing 4 to 6 weeks after placement for the concrete to fully cure and color to even out. If that does not work, you can try light powerwashing, scrubbing with a detergent, and acid etching. If you use any acidic materials to etch or clean, make sure to neutralize!
Broom finishes are commonly used with colored concrete. Discoloration when brooming is often caused by excessive moisture, “wet-brooming,” worn tools, using different types of brooms on the same job, or inconsistent technique. The best way to prevent these issues are to avoid them! Use the same tool and technique as much as possible and avoid adding any moisture. To remedy broom-related issues, you will likely need to acid etch, sandblast, or soda blast the surface. This could alter the texture of the slab.
Most of the above solutions involve etching and mechanically removing some of the concrete to repair color. This does not always work. In those cases, you may need to rely on other coloring techniques to repair, obscure, or cover up blemishes and discoloration:
Adding a tint pack, such as Brickform Tinta’ Seal, to your sealer is a quick and easy way for minor color correction. By tinting the sealer, you give a slight, transparent color to the surface of the concrete. It is good for evening out inconsistent color and obscuring minor defects. Tinted sealer is also good for temporary coloration, as the color will only last as long as the sealer.
Stains and Dyes
Much like tinted sealers, stains and dyes give transparent color to the concrete surface, but on a more permanent basis. They are good for evening out and obscuring uneven color and minor blemishes. Getting creative with stains, you can create a mottled look and incorporate uneven coloration into a pleasant design feature.
If you desire a “clean slate” or the discoloration is too significant, consider an opaque cover up. Brickform Cem-Coat is an opaque, cementitious “paint” that essentially creates a new surface. Applying Cem-Coat gives you a solid color surface that can be stained, sealed, and otherwise treated just like the original concrete – somewhat like a microtopping, but thinner and easier to apply. Alternatively, for more textured concrete surfaces, Brickform also offers FreeStyle Pro, an opaque stain. FreeStyle Pro is a thin-build, self-sealing stain that works wonderfully with stamped and textured concrete.