Colored Concrete Finishes

Colored concrete fi nishes can involve applying a color-hardening agent to the concrete after the slab is placed or may require adding an integral pigment to the concrete mixture. The integrally colored technique requires a clear coating to provide protection. The color-hardening agent strengthens the slab surface while providing the desired color and texture. This technique requires more experienced skilled labor to perform the application correctly.

Integral Color
Preparation: Installed with slab.
Price: $3-$4 per sq. ft.
Life Expectancy: Life of slab
Pro/Con: Integral color throughout the slab thickness, but no added slab protection or resistance to chemicals.

Color Hardened
Preparation: Clean and provide texture.
Price: $2.50-$4 per sq. ft.
Life Expectancy: N/A
Pro/Con: Good protection but expensive and susceptible to chemical attack.

Painted Concrete Finishes
Painted finishes use an epoxy paint, which is durable and more economically installed than a typical epoxy coating.
The compromise comes in the protection provided. Moisture in the slab may cause bubbling and cracking, and combined with hot apparatus tires the surface can delaminate. The thin coating provides minimal long-term protection against heavy abuse associated with apparatus bays.

Preparation: Clean slab, test for moisture and provide texture by acid etching or shot blasting.

Price: $.75-$1.25 per sq. ft.
Life Expectancy: 1-2 years
Pro/Con: Economical but provides little protection.

Concrete Sealers
Concrete sealers, another thin application, may be clear or colored and provide protection against moisture and chemicals. Sealers tend to be an economical option, but don’t provide the same durability as other systems. Sealers also require a higher degree of maintenance as warm tires may pull up sealed areas and cause some flaking. This may be easily repaired, but is susceptible to the same attack in the future. Sealers also don’t provide the long-term protection against abuse and wear that is associated with the type of heavy equipment that occupies apparatus bays.

Preparation: Clean slab, test for moisture and provide texture.
Price: $1-$1.50 per sq. ft.
Life Expectancy: 1-2 years
Pro/Con: Economical with slightly more protection, but requires more maintenance and provides less protection than thicker systems.

Polymer Coated Concrete Finishes
Polymer coatings, generally thicker installations, provide the opportunity for less maintenance and longer-lasting protection but at a higher expense. The two most commonly used types are epoxies and polyurethanes. These two systems offer a variety of color and texture options, as well as a wide range of protection. The level of protection, however, varies with the thickness of the system; in general, a thicker systemprovides more protection for the
concrete slab.

Epoxy systems adhere well to surfaces. This makes these systems less susceptible to flaking or pulling away from the concrete when the surface is prepared properly.
Improper preparation of the concrete slab may lead to bubbling and cracking as moisture attempts to leave the system.

Polymer coatings use an epoxy base to maintain strong adhesion properties. Differing from epoxy coatings, polyurethane systems contain volatile organic chemicals (limited by some authorities). These systems also resist yellowing—a concern with epoxy systems constantly exposed to ultraviolet light. While manufacturers of polymerbased systems provide possibilities for seamless installations, it is a common misconception it will not crack when applied without joints. It is wise to provide control/expansion joints in the system, coordinated with slab joints, to accommodate the same movement that occurs in
the slab.

Preparation: Clean slab, treat for moisture and provide texture.
Price: $2.75-$4 per sq. ft.
Life Expectancy: 10-15 years
Pro/Con: Good protection but expensive.

Installing Floors
Whether it is a new or existing slab, a quality coating can only be accomplished  with a quality concrete slab installation. During installation of your apparatus bay
floor, compliance with manufacturer’s requirements and preparation of the concrete surface is crucial. Clean the slab and check to ensure it contains acceptable
moisture levels appropriate for the product and testing authority.

The American Society for Testing of Materials (ASTM) has a standard for testing moisture (D4263), but this test is focused on moisture at the top of the slab. It may be necessary to test the moisture levels deeper in the slab thickness. Also, ASTM has developed standards for providing a clean surface in preparation for coatings. These standards range from simple cleaning of the top of the slab surface (D4258) to physically or chemically removing the surface layer to provide a rough bonding surface (D4259 and D4260). Finally, any concrete surface with imperfections such as cracks and chips must be repaired prior to coating application.

Non-slip Surfaces
In a recent Cole + Russell survey, 24.3% of fire officials indicated that slip hazard was a primary flooring concern. Nearly all the
systems described have the capability of providing varying levels of non-slip surfacing.

Integrally colored, colored-hardened and sealed concrete may take advantage of the texturing of the concrete itself to provide a non-slip surface. The polymer coatings provide the capability of a non-slip surface by using varying levels of coarse sand cast in the finish coat to produce varying grits. The slip resistance varies among products and finishes, but you can make comparisons using the standard test methods ASTM F-489 and ASTM F-609.

Floor durability, treatment, chemical usage, the appearance desired and cost all factor into choosing the right floor finish. To determine which of the various
options is best for your department, first identify your needs and preferences. Remember, the system you choose is an investment in your station, your equipment, and your personnel. For additional information or assistance regarding floor finishes, please contact Cole + Russell Architects.