To finish strong you need a strong insulation adhesive. EPSA is a 100% pure acrylic one-part adhesive for wood or gypsum surfaces. EPSA offers excellent initial grab that improves over time.


VOC: <1% by Weight
Manufacture Locations: 30058 • 77474 • 84651
Recycled Content: 0%

Packaging: 5 gallon (19L) pail

Pail Weight: 45 lbs (20.4 kg)

Coverage (estimated)
150-225 sf (14-21 sm)

Working Time: 1/4 hour @ room temperature

Drying Time: 24 hours @ room temperature

Application Range: 45º-110ºF (7º-43ºC)

Shelf Life: 2 years

Approved Substrates

Exterior gypsum sheathing
(ASTM C1396, C1177)
Dens Glass Gold®
Gold Bond e2xp®
Exterior Plywood
Oriented Strand Board (OSB)
Others approved in writing

Application Procedure

Job Conditions – Air and substrate temperature for application of EPSA must be 45°F (7°C) or higher and must remain 45°F (7°C) or higher for a minimum of 24 hours. Provide temporary protection to protect the wall system from damage until permanent flashings, caps and sealants are installed. Store materials within prescribed temperature limits and out of direct sunlight. Working and drying times are based upon normal room temperature conditions and will vary with temperature and humidity.

Preparation – The substrate must be approved by Master Wall Inc., clean, dry, structurally sound and free of efflorescence, oil, grease, form release agents and curing compounds or anything that would affect bond. Painted surfaces or treated wood panels are not acceptable. For installation of wood-based sheathings, follow the American Plywood Association guidelines.

Mixing – Thoroughly stir EPSA using a heavy duty 1/2” (12.7 mm) drill at 400 – 500 rpm and a heavy duty mixing paddle. Do not add water.


Adhesive application – Apply the EPSA directly to the back of the insulation board using a 3/8” x 1/2” (9.5 mm x 12.7 mm) U-notched trowel with the ribbons no further than 2” (50.8 mm) o.c. With the trowel at a 45º angle, cover the entire surface of the back of the insulation board with full beads of adhesive formed by the notched trowel.

Immediately place the prepared insulation board on the substrate. Make sure that all edges of the insulation board are abutted tightly and that no EPSA gets into the board joints. Do not allow the EPSA mixture to form a skin prior to placing the insulation board on the substrate. Apply firm pressure to the entire surface of the insulation board to ensure solid contact between the insulation board and the substrate. Do not apply the EPSA mixture directly onto the substrate.

Clean Up—Tools and equipment can be cleaned with soapy water while the EPSA is still wet.

Limitations – Not intended for use with Drainage EIFS or for adhering foam shapes to insulation board.

Information contained in this product data sheet conforms to the standard detail recommendations and specifications for the installation of Master Wall® Inc. products and is presented in good faith. Master Wall Inc. assumes no liability, expressed or implied as to the architecture, engineering, or workmanship of any project. This information may be concurrent with, or superseded by other applicable documents, such as specifications and details. Contact Master Wall® Inc. for the most current product information.

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