Epoxy primer inhibits moisture vapor emissions

Series 208 Epoxoprime MVT is a two-component, clear agent with low viscosity to penetrate and adhere to new and existing concrete slabs. Series 208 is specially formulated to resist high pH and help protect the bond line between the floor topping system and concrete surface.

The high-solids epoxy primer, Series 208 Epoxoprime MVT, reduces the potential for coating failure due to the high alkalinity typically associated with moisture vapor transmission.

“Moisture vapor-related coating failures in new and existing concrete are common,” notes Tnemec StrataShield Flooring Division Joe Schmit. “Bubbling and blistering, which can lead to delamination of a coating system, occurs when moisture vapor travels upward through the concrete floor—carrying with it various highly alkaline components, such as salts and chlorides which raise the pH and attack the coating system at the bond line.”

Applied at 16-20 mils dry film thickness, Series 208 penetrates the concrete surface to provide excellent adhesion and ultra-low permeability, helping to reduce moisture from escaping new and existing slabs where elevated moisture vapor transmission levels are of concern. The primer can be applied as early as 10 days after newly placed concrete is installed versus the standard 28-day cure time. The 100 percent solids primer conforms to the volatile organic compound requirements of every air district in the U.S. and its low odor allows it to be used in occupied areas.

“Even when concrete is at full strength and fully cured, the substrate is still porous, so moisture vapor transfer and high alkalinity may still be a concern,” Schmit observes. “Series 208 offers added assurance for existing concrete where MVT levels exceed the capabilities of other concrete flooring primers.”

Series 208 withstands moisture vapor transmission up to 15 lbs. in accordance with ASTM F1869 Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Chloride. The primer withstands relative humidity up to 95 percent in accordance with ASTM F2170 Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes. The primer also offers resistance to high alkalinity levels up to pH 14.

Following application, Series 208 can be topcoated after six to eight hours of cure time at ambient temperatures. The product has been used successfully in combination with epoxy and epoxy-urethane topcoat systems for color and gloss retention. Tnemec Co., Kansas City, Mo., 800/863-6321; www.tnemec.com