Bostik EFA - 4 Gal

Bostik EFA+ is a high-performance, one-part, moisture-cure urethane adhesive designed specifically for hardwood flooring installations. It also serves as a moisture-vapor control membrane, making it a versatile solution for bonding and protection in one product.

Key Features & Benefits

• Easy to trowel & apply — The adhesive flows smoothly and allows for efficient installation. 

• Flexible, durable bond — Thanks to its elastomeric properties, EFA+ moves with the wood as it expands and contracts, minimizing stress and risk of delamination. 

• Built-in moisture protection — When applied per manufacturer directions, EFA+ acts as a moisture vapor retarder that can reduce moderate moisture vapor transmission from the subfloor. 

• Low VOC / No water content — The formulation contains no added water and maintains low volatile organic compound levels, supporting healthier indoor air quality. 

• Versatile substrate compatibility — Suitable for many common subfloors including concrete, plywood, OSB, well-bonded vinyl, ceramic tile, gypsum underlayments (above grade), radiant-heat systems, and terrazzo when prepared properly. 

• Wide flooring type compatibility — Works with engineered wood, solid hardwood (adhesive-only), bamboo, cork, and parquet flooring. 

Typical Applications

• Interior residential and light commercial hardwood flooring installations

• Projects where moisture protection is a concern but full moisture mitigation systems may not be required

• Subfloors with moderate moisture levels (for example, up to 15 lbs per 1,000 sq ft/24h MVER or up to ~87% RH in certain cases) when used as specified.