Barrier-Bac

Project Owner: Certura 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

Background:

Centura Health, Colorado's largest health care provider, built four new hospitals in Colorado during the last five years. The newest facility, located in Castle Rock, was designed and built to offer state-of-art health care to better meet the needs of the growing community in the Castle Rock area.

Conditions:

Because of shifting mountain 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 to be used beneath the concrete slab-on-grade portion of this project.

Previous experience using standard, smooth-surfaced vapor barrier with no peel adhesion to concrete, in cases where high-end flooding is specified, resulted in poor performance. In their experience, specifying a vapor barrier with peel adhesion to the concrete is critical. A vapor barrier with excellent peel adhesion to the bottom of the concrete slab-on-grade for the Centura Health facility was imperative to ensure the problem of vapor barrier "Pocketing" would not occur.

Pocketing is when the vapor barrier separates from the bottom of the slab, which occurs during regular sub-grade 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.

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 from 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 the practice of health care in a first-class medical care building free from flooding and health issues created by water vapor moisture migration through the concrete slab-on-grade.