Use Bostik EFA+™ for an easy-to-trowel elastomeric urethane hardwood floor adhesive & moisture vapor retarder.

Wood Flooring Adhesive and Moisture Vapor Retarder

Request Pricing  |  Download TDS  |  Specifications  |  Request SDS  |  Technical Support

Bostik EFA+™ is an easy-to-spread, low-VOC urethane hardwood flooring adhesive

Bostik EFA+™ is an easy-to-trowel urethane adhesive and moisture control membrane. It provides a tough, flexible, tenacious bond to a variety of surfaces. Its elastomeric characteristics allow EFA+™ adhesive to move with the wood as it expands and contracts over the life of the floor. Bostik EFA+™ exhibits a long open time making installation easier and faster. This adhesive has low VOC’s and does not contain any water.

EFA+™ provides moisture protection

Bostik EFA+™ has low moisture vapor permeability and is not adversely affected by moisture. As a result, it will reduce moderate amounts of moisture vapor transmission through the concrete. When applied as directed as a moisture vapor membrane, it will prevent damages caused by subfloor moisture beneath dimensionally stable, engineered wood flooring only.

EFA+™ may be used for concrete slabs with elevated moisture levels up to 6 lbs. per 1,000 square feet per 24 hours (using an anhydrous calcium chloride test kit according to ASTM F-1869 test method), and up to 80% RH (tested in accordance with ASTM F-2170). For substrates that have an MVER of greater than 6 lbs or 80% RH, use Bostik MVP4™ prior to the application of EFA+™ for unlimited moisture vapor protection, or use Bostik Ultra-Set® SingleStep2™ or GreenForce™.

EFA+™ provides superior elasticity and anti-fracture performance

The elastomeric characteristics of Bostik EFA+™ establish an anti-fracture membrane that can bridge cracks up to 1/8" (3mm), which can occur in the substrate prior to or after installation. This superior elasticity allows the adhesive to move with the wood as it expands and contracts with changes in humidity and temperature over the life of the floor.

Use Bostik EFA+™ for ultimate versatility

EFA+™ may be used to adhere all engineered, solid (adhesive only), bamboo (adhesive only), cork, and parquet hardwood flooring (adhesive only) to appropriate substrates. Bostik EFA+™ can also be used to install plywood as described, as well as ceramic tile, marble, and stone inlays for light commercial or residential applications.

EFA+™ may be used over all properly prepared substrates common to hardwood flooring installations including: concrete, plywood, OSB, well bonded vinyl/VCT and ceramic tile, cement backer board, gypsum underlayments (dry, above-grade), cement patch/underlayments, radiant-heat flooring, and properly prepared terrazzo.

Where to Use Substrates Materials
Residential Concrete Solid hardwood flooring
Offices and light commercial Plywood Engineered hardwood flooring
Heavy commercial OSB Bamboo flooring
  Well-bonded vinyl Cork flooring
  Terrazzo Parquet flooring
  Ceramic tile Plywood
  Cement backer board Ceramic tile, marble, and stone inlays (in residential or light commercial only)
  Gypsum underlayments (dry, above-grade)  
  Cement patch/underlayments  


back to top