AirSTOP for CMU
Master Wall® AirSTOP for CMU is a premium dry polymer-modified Portland cement-based air and water barrier that integrates into approved Cemplaster Fiberstucco and approved Cobrand stucco products for a complete air and water solution over concrete and masonry substrates. AirSTOP is a dual-purpose product that may be applied under ASTM C926 stucco as a concealed application or as a skim or leveling coat on the surface.
Features & Benefits
- Air Control
- Adds Water Resistance
- Engineered Stucco Scratch Coat
- Stucco Leveler
- Vapor Open
- Convenient Bags for easy storage
Master Wall Inc.® AirSTOP for CMU Typical Details
| MWAS-01 | STANDARD AND IMPACT CROSS SECTION | |
| MWAS-02 | DETAIL AT GRADE | |
| MWAS-03 | DETAIL AT GRADE WITH WATERPROOFING | |
| MWAS-04 | TYPICAL WINDOW HEAD | |
| MWAS-05 | RECESSED WINDOW HEAD | |
| MWAS-06 | WINDOW JAMB | |
| MWAS-07 | RECESSED WINDOW JAMB | |
| MWAS-08 | WINDOW SILL | |
| MWAS-09 | RECESSED WINDOW SILL | |
| MWAS-10 | MASONRY CONTROL JOINT | |
| MWAS-11 | TYPICAL PENETRATION | |
| MWAS-12 | ROOF CAP | |
| MWAS-13 | AIRSTOP OVERLAY | |
| MWASSD-01 | AIRSTOP WITH CR (CRACK RESISTANT MESH) OVERLAY – SPECIAL DETAIL |
Coverage per bag (sf/m2)*
Skim & Scratch Coat: 90-100 ft2 (8.4 – 9.3 m2)
Skim Coat: 130-150 ft2 (12.1 – 13.9 m2)
*Coverages are approximate and will vary depending on mix ratio with water, application technique, waste factor, surface conditions, and other variables that may exist. Construct a mock- up under actual conditions of use to verify proper surface preparation, coverage, and method of application, for approval by the appropriate authority.
Packaging/Shelf Life/Storage
Packaging: 50 lb (23 kg) bag
Shelf Life: 1 year
Storage: Store off the ground in a cool, dry area. Protect from extreme heat, moisture, and direct sunlight.
Technical Data
Compression (ASTM C270): 24 hours – 500 psi (3447 kPa), 7 day – 2700 psi (18,615 kPa), 28 day – 3350 psi (23,097 kPa)
Tensile Strength (average): 7 day – 310 psi (2137 kPa), 28 day – 395 psi (2723 kPa)
Shear Strength (average): 7 day dry – 467 psi (3219 kPa), 7 day wet – 395 psi (2723 kPa), 28 day dry – 537 psi (3702 kPa)
Sag Resistance: 0-.485
Water Vapor Transmission: Vapor Permeable
·Air Leakage Resistance (ASTM E2178): <0.004 cfm/ft² @ 1.57 psf, (< 0.02 L/m²·s @ 75 Pa)
Complies with 2018, 2021 and 2024 IBC, IRC, and IECC requirements as an air barrier material
Complies with 2020, 2023 FBC requirements as an air barrier material
Complies with 2020, 2023 FBC requirements as an air barrier assembly when used with Master Wall® SuperiorShield components and other components specified by the code