Cure For Contaminated Cement: Encapsulate With Epoxy

Many state and local pollution control agencies have found that encapsulating contaminated concrete is the most economical and long-lasting solution for preventing the contaminants from entering the environment.

Durall Industrial Flooring's Dura Poxy provides an ideal solution for this purpose. Dura Poxy is a 100% solid epoxy capable of sealing contaminants into the concrete when applied with a thickness of 10 to 100 mils. The encapsulation works much like an insect trapped in amber. Solids, gasses, and liquids are all trapped inside a solid, hard capsule. Contaminants are thus able to be left in place, with no danger to crews that might have had to work in close proximity to remove them.

Durall recommends choosing a white, yellow, or red color for the first coat, or "seal coat." Subsequent topcoats are a contrasting color like gray or brown. In this way, workers moving around the contaminated surfaces are alerted when wear has made re-coating necessary. The contrasting colors thus provide a "wear meter."

When applying floor seals that can be 20 to 500 mils thick as they repair and level imperfect floor surfaces, it is critical to consider the height of the coating in addition to the length and width issues of normal roll-on applications. When water is poured on glass, it protrudes above the surface at the edges. Pulling a finger though the water, one sees flattening at the entry and exit points due to its surface tension. When leveling floors, these same effects of the epoxy's surface tension must be dealt with. In other words "self-levelling," which is incomplete even for liquids like water, will not produce a flat top layer of epoxy.

Dura Poxy does not shrink and will harden at any height it is left at after being catalyzed. But special procedures are needed in order to assure a flat surface while filling uneven anomalies in the substrate. Durall has found that using a squeegee-like motion with a very short nap roller (3/16") creates a pool of epoxy that can be pulled towards you to leak into low spots while keeping the surface flat. Care must be used to apply an even coat at the surface, and too much rolling can cause the surface to try to contour along the floor's imperfections.

SOURCE: Durall