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As the popularity of concrete countertops continues to increase, concrete countertop fabricators and designers are looking for new and innovative ways to market and offer concrete countertops. One emerging application of concrete countertops is in the area of outdoor kitchens. With this new area of the market comes a new set of challenges and design opportunities, one of which is how to handle colored concrete for the outdoors. Here are a few points to remember for colored concrete for outdoor applications:

1. Not all concrete or concrete colorants are equal—especially when exposed to direct outdoor sunlight and/or weather conditions. Therefore, if concrete countertops are going to be used in these outdoor conditions, it is essential that a suitable colorant is used in order to lessen or avoid fading and loss of color intensity. Generally speaking, carbon black and some organic blues and violets are particularly prone to color shifts and are best avoided in outdoor applications.



2. And, while all concrete countertops should be sealed to avoid staining, those used outside may require periodic sealing and maintenance in order to help resist fading or loss of color intensity. However, even when sealed, some color change can be expected over time. Part of this shift occurs in all colored concrete; however when the intensity of the color is very high (as with strong blues and violets), the perceived color shift seems far more severe. On the other hand, color shifts in earth tones and lighter color shades are more subtle and are not as easily noticeable—sometimes resulting in the perception that the concrete has not changed in shade or color.



3. Finally, color stability of the concrete is directly related to the quality and durability of the concrete. The denser and less porous the concrete, the less likely colors will be affected by exposure to weathering and fading. It is also worth noting that all concrete goes through color changes. Concrete will "yellow" slightly over time and will lighten for some length of time after the initial casting and de-molding of the piece. This is especially evident during the first few weeks after de-molding.
   
   Sealing at about 7-10 days after de-molding will tend to slow the process and yield a slightly darker color than waiting several weeks before sealing the concrete piece. Concrete continues to cure and lighten over time and will do so as long as there is any moisture available in the concrete (in humid environments, it is not unusual to see slight lightening for the first 6 months, although in most cases it will not be noticeable as it is a gradual process).

Cheng NeoMix Colors in Outdoor Settings

Our Cheng NeoMix colors have been blended and designed for use in interior applications (with no reported color stability issues other than normal color lightening from loss of moisture which is well within acceptable limits). Not all of NeoMix colors are well-suited for outdoor use and the following guidelines should be considered before using a NeoMix color for an outdoor application.

Greens: "Forest"

• Good Outdoor Color Stability
• Reasonably stable over time. With proper sealing and maintenance, you should see only normal lightening of the concrete itself.

Blues: "Aquamarine"

• Reasonable Outdoor Color Stability

Blacks / Black-Blues: "Charcoal, Indigo"

• Poor Outdoor Color Stability
• Carbon Black-based colors should be used with caution outdoors

Naturals: "Stone"

• Good Outdoor Color Stability
• Slight color shifting due to the concrete curing process

White: "Platinum"

• Good Outdoor Color Stability
• Tendency to get "dirty" and very slight yellowing over time

Tans: "Sand"

• Good Outdoor Color Stability
• Long term yellowing (very slight in most cases)

Green Blends: "Olive"

• Reasonable to Good Outdoor Color Stability
• Long term yellowing (very slight in most cases)

Reds: "Brick" and "Wine"

• Good Outdoor Color Stability
• Long term yellowing (very slight in most cases)

Browns: "Saddle"

• Good Outdoor Color Stability
• Long term yellowing (very slight in most cases)

Special Colorants: "Amethyst"

• Color Stability is variable and greatly dependant on the integrity of concrete and sealer

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