Description

About SPEC MIX Scratch & Brown Stucco

SPEC MIX Scratch & Brown Stucco is a scientifically computer-batched, dry, pre-blended cementitious material designed for professional construction applications. It is engineered to serve as the base layers in conventional three-coat stucco systems. The mixture combines Portland cement, hydrated lime, and oven-dried sand with proprietary admixtures to ensure consistency and workability. This product is formulated to replace job-site mixing, providing a uniform material that integrates established quality controls during manufacturing.

As a factory-blended stucco base, this material eliminates the variability often associated with field-batched sand and cement. It is suitable for application over installed metal lath or solid masonry substrates, functioning effectively as both the initial scratch coat and the subsequent brown coat processes. The material allows for specific formulation adjustments, such as the inclusion of synthetic fibers, depending on project requirements.

SPEC MIX Scratch & Brown Stucco Technical Specifications

• Composition: Portland Cement (ASTM C 150), Hydrated Lime (ASTM C 207), Sand (ASTM C 897), Proprietary Admixtures
• Compliance Standard: Meets ASTM C 926 requirements
• Compressive Strength: 1,900 PSI at 28 days (ASTM C 109)
• Water Retention: Greater than 75% (ASTM C 1506)
• Yield (80 lb Bag): Approximately 0.70 to 0.75 cubic feet
• Coverage (80 lb Bag): Approximately 18 to 20 square feet at 1/2 inch thickness
• Packaging Types: 80 lb (36.2 kg) paper bags, 3,000 lb (1,360.7 kg) bulk bags

Applications & Material Features of SPEC MIX Scratch & Brown Stucco

SPEC MIX Scratch & Brown Stucco is primarily utilized in the installation of three-coat stucco wall systems. It is applied directly to metal lath or prepared concrete and masonry surfaces to build the necessary thickness and structural plane before the application of finish coats. The pre-blended nature of the product ensures sand gradation consistency, which aids in trowelability and application efficiency.

The material features high water retention properties, which are essential for proper hydration and curing of the cementitious components. It is compatible with mechanical pumping equipment as well as traditional hand-application methods. By using oven-dried and double-screened aggregates, the mix reduces the risk of deleterious materials affecting the final stucco integrity. This product serves as a foundational substrate for various exterior finishes.