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StoPowerwall® ExtraSeal®
StoPowerwall® ExtraSeal®
StoPowerwall® ExtraSeal®

    StoPowerwall® ExtraSeal®

    StoPowerwall® ExtraSeal is a portland cement stucco wall covering that is intended for use over code compliant concrete and concrete masonry wall construction. It incorporates Sto ExtraSeal® , a trowel applied water-resistive air barrier, StoPowerwall® portland cement stucco, Sto primers, and Sto textured or StoCast finishes.

    Sto ExtraSeal is the water-resistive air barrier component of the system and is applied as a skim coat and scratch coat directly to concrete and concrete masonry. StoPowerwall stucco is applied as a brown coat over the Sto ExtraSeal scratch coat. StoPowerwall stucco is ASTM C9261 compliant and is installed in conformance with ASTM C926 practices. StoPowerwall stucco is available as a concentrate to which graded sand is added at the job site, or pre-sanded to simplify mixing in the field.

    Sto proprietary integrally colored textured finishes or StoCast finishes are used in lieu of portland cement stucco finish to achieve brighter, richer colors and textures, and offer a wide variety of finish looks such as stone, brick, or wood on a single substrate.


      • Commercial or Residential
      • Vertical, above grade wall construction
      • Exterior and Interior environments
      • Approved for Concrete Masonry, Core-filled CMU
      • Air and Moisture Barrier Performance:  ICC ESR 2323, ASTM E 2178, ASTM E 514, ASHRAE 90.1-2019
      • Fire Compliance: Suitable for Types I-V construction and ASTM E119
      • Uses ASTM C 926 compliant stucco scratch and brown coat
      • Air Quality and VOC Compliance: US EPA (40 CFR 59) and SCAQMD (Rule 1113)
      • LEED Credit Eligibility: EA, MR, IA
      • R-Value: 0.15 – 0.18 ft2•h•°F / Btu (0.026 – 0.031 m2 •K/W)
      • System Weight: < 7 psf (34.2kg/m2)
      • 10 Year Limited Warranty, with Sto Crack Defense 
      Concrete barrier commercial residential masonry drainage wood stud façade cladding walls water barrier drain screen
    Technical specification
    • Unique ref.sto_powerwall_extraseal
    • Product familyWalls
    • Product groupWall Cladding Sheets
    • TypeAssembly (multiple objects)
    • Date of publishing2022-09-12
    • Edition number1
    • Material mainPolymer-modified cementitious
    • Material secondaryFibreglass reinforced polymer composite
    • Designed inUnited States
    • Manufactured inUnited States
    • BIMobject CategoryWalls - Cladding
    • IFC classificationWall
    • UNSPSC nameSiding and exterior wall materials
    • UNSPSC code301518
    • Uniclass 2015 CodeEF_25_10
    • Uniclass 2015 DescriptionWalls
    • CSI MasterFormat 2014 Code09 24 23
    • CSI MasterFormat 2014 TitleCement Stucco
    • OmniClass Number23-13 33 15
    • OmniClass TitleWall Exteriors
    • CSI UniFormat II CodeB2010
    • CSI UniFormat II TitleExterior Walls

    Region availability

    North America
    United States