What performance criteria must asphalt emulsion meet for use as a vapor barrier under slabs?

As a vapor barrier, the cured film must be continuous, pinhole-free, and durable under concrete placement and service. Key criteria include low water vapor permeance, strong adhesion to the substrate, resistance to alkalinity from concrete, and puncture and abrasion resistance. The system must also tolerate minor substrate movement and not re-emulsify or soften with intermittent moisture. Application must achieve the specified dry film thickness and curing time before concrete placement. Many projects require system testing or certification to relevant building standards for vapor retarders.