CASE STUDIES

Composite Vapor
Barrier Protects Flooring

Centura Health Hospital

Barrier-Bac composite vapor barrier provides long-term protection for on-grade flooring systems of a medical facility in a mountain soil environment.

Project Owner: Centura Health, Englewood, CO.
Architect: Hunton Brady Architects, Orlando, FL.
Contractor: GE Johnson Construction Company, Greenwood Village, CO.
Product: Barrier-Bac, VBC-350, 31 mil, Composite Class A vapor barrier

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Background

Centura Health, Colorado’s largest healthcare provider, built several new hospitals in Colorado during the last decade. One facility, located in Castle Rock, offers state-of-art health care to better meet the needs of the growing community in the Castle Rock area.

Conditions

Because of shifting soil conditions and the high-quality epoxy flooring systems used in the construction of this facility, Hunton Brady chose Barrier-Bac’s VBC-350, 31 mil composite for use beneath the concrete slab-on-grade portion of this project.

In previous experience, standard vapor barriers without peel adhesion to concrete, resulted in poor performance with high-end flooring.

Vapor barrier “pocketing” occurs when the vapor barrier separates from the bottom of the slab, which occurs during regular subgrade settlement, thereby forming areas between the concrete slab and vapor barrier where water condensation pools. The moisture then migrates upward through the slab, potentially damaging the sensitive flooring system. Facility was imperative to ensure the problem of vapor barrier “pocketing” would not occur. Specifying a composite vapor barrier with peel adhesion to the concrete was critical to protect this flooring.

How it works

Barrier-Bac VBC-350 is composed of a 16-mil polyethylene ASTM E 1745 Class A vapor barrier membrane, which is laminated to a polypropylene non-woven geo-textile fabric. This particular composite vapor barrier is installed with the non-woven side facing the concrete pour, and as the concrete cures, fibers of the non-woven material become mechanically bonded to the slab. This ensures integral bonding of the vapor barrier system to the concrete and eliminates any problem which might be caused by separation of the vapor barrier from the bottom of the concrete slab.

Conclusion

By integrating Barrier-Bac VBC-350 composite vapor barrier into its project, the designer — Hunton Brady Architects — helped ensure that the staff and clients at this facility will experience a first-class medical care building free from flooding and health issues created by water vapor moisture migration through the concrete slab-on-grade.