FLORPRUFE® Bonded Vapor Barrier

An integrally bonded vapor barrier for on-grade concrete.


It’s not easy to work with on-grade concrete. Water vapor can easily migrate up from the ground, through cracks in the concrete, and into carpet, vinyl tiles, hardwood floors and more. This causes expensive and unsightly problems in turn. The solution is to put a vapor barrier between the concrete slab and the ground itself — so what are the characteristics of a top-of-the-line vapor barrier?

Comply with ACI recommendations

Most flooring and finishes are sensitive to moisture—they will stain, warp, or become moldy if not kept dry. For on-grade construction, the American Concrete Institute recommends that a concrete slab should have a vapor barrier underneath it if there’s a moisture-sensitive covering on top. A high-performance vapor barrier will adhere to concrete as closely as possible—and FLORPRUFE®  is the only system that uses Advanced Bond Technology™.


Permanent, continuous adhesive bond to concrete

When concrete is poured over the FLORPRUFE® vapor barrier, it reacts with the barrier’s non-tacky adhesive coating. The adhesive forms a permanent integral seal with the concrete itself. Not only does this prevent water from infiltrating the underside of the slab, it also prevents the barrier from losing contact with the slab due to settling. Loose-laid systems can’t approach the performance of the fully-bonded GCP system, which offers long-lasting performance for critical areas and sensitive applications.

Installs easily

In addition to providing a nearly impermeable seal against vapor, FLORPRUFE® is designed to make life easier for contractors. A simple kick-out design lets builders install the barrier with the smallest possible team. In the meantime, workers can easily form laps using either mechanical fasteners or PREPRUFE® tape. A sturdy polyolefin backing resists both job-site conditions and moisture infiltration. All in all, workers can achieve a waterproofing solution that vastly exceeds industry standards for slab-on-grade concrete without putting in any additional effort or expense.

Products & Accessories


  • Product Name
  • Description
  • Key Benefits
  • Applications Type
FLORPRUFE® 120 Data Sheet

FLORPRUFE® 120 is a high performance vapor barrier with GCP’s Advanced Bond Technology™ that forms a unique seal to the underside of concrete floor slabs.

Key Benefits
  • Forms a powerful integral seal to the underside of concrete slabs
  • Protects valuable floor finishes
  • Direct contact with the slab
Application Type

FLORPRUFE® 120 is engineered for use below slabs on grade with moisture-impermeable or moisture-sensitive floor finishes that require the highest level of vapor protection.