Preblended Cement Base Coat

Standard (SU-05)



  • Computer batched for consistency and performance unmatched by traditional field mixed stucco.
  • Custom blended sand gradation that increases the wall flexural strength while reducing cracking and crazing.
  • Excellent workability an finishing properties for the applicator over a traditional field-mixed source
  • Reduced shrinkage and increases long term durability and bond strength of the application

SPEC MIX® Fiber Base Coat (FBC) is a dry, preblended cement based stucco engineered with proprietary admixtures and fibers that are computer batched for consistency and performance unmatchedby traditional field mixed stucco. SPEC MIX FBC has a custom blended sand gradation that increases the wall flexural strength while reducing cracking and crazing. The custom sand gradation also provides excellent workability and finishing properties for the applicator over a traditional field-mixed source.

Designed for both One Coat and traditional Scratch & Brown Coat systems, SPEC MIX FBC reduces shrinkage and increases long term durability and bond strength of the application. When gun or hand applied by a qualified applicator, SPEC MIX FBC is approved by Intertek as a one-hour fire rated wall when applied as a One Coat application, CCRR-0231. Submittals are available upon request for certification to applicable ASTM standards.

What separates SPEC MIX Fiber Base Coat from other stucco products is our international team of manufacturers providing sophisticated batching facilities ensuring SPEC MIX FBC’s total product quality control. No matter if the project is a single-family home, multi-family complex or a commercial building, quality assurance and applicator satisfaction is our objective.

Raw material selection is another key to making SPEC MIX FBC the industry’s top performing preblended stucco. SPEC MIX manufacturers consistently select and blend the finest raw materials available to eliminate contaminants entering the mixture that can lead to efflorescence, color variations, sagging and low strength. Because the quality of stucco sand varies from source to source, SPEC MIX product engineers uniquely focus on sands that comply with ASTM standards. Since the sand makes up as much as 70 percent of the final mix, using the best possible aggregates is imperative to manufacturing a high performance product. When the preblended SPEC MIX FBC is mixed and applied, the end result is a stucco wall with a tensile strength that reduces the risk of cracking and crazing in the system. As for application, the plasterer is equipped with a mix that provides superb workability and excellent finishing properties.

When contractors combine a SPEC MIX silo delivery system with SPEC MIX FBC stucco production on their job site, material quality and consistency, as well as the level of efficiency and productivity gained, cannot be equaled by traditional field-mixing methods. Unlike fieldmixed stucco, there is no room for error with SPEC MIX FBC—just add water and mix as instructed, no other materials need to be added. While traditional field-mixing methods can lead to inconsistent product, testing issues, wasted labor and materials as well as poor productivity, the SPEC MIX system increases product quality, cuts waste and risk of back injury while improving material production by as much as 50 percent.

SPEC MIX is an innovator in preblended stucco development. For over 20 years SPEC MIX has lead the preblended construction products industry with this type of innovation and by meeting these three objectives for all our professional products: Quality. Consistency. Efficiency. If the brand says SPEC MIX you are assured it delivers on all three.


The driving force behind our commitment to quality and our statement to the design community is: “What you specify is what you get!” Our process embraces our commitment to supply superior products. Quality control starts at the beginning of the material manufacturing process. That means it starts with the raw materials. The SPEC MIX quality control process requires that each raw material is pre-weighed and computer batched and blended for optimal consistency and field performance. Every batch of SPEC MIX FBC is produced using this unique production process. Only high quality local materials are selected. This process makes the optimum blend of material, and each mix constituent is required to meet ASTM standards. Our state of the art licensed manufacturing facilities ensure only designated formulation is packaged and delivered. Unlike field-mixed stucco, to validate our quality control, a digital printout displaying the actual proportions of materials in each batch may be kept as a permanent record by the contractor.

SPEC MIX Fiber Base Coat outperforms conventional stucco. The data shows it conclusively provides superior physical properties including: consistent compressive strength, reduced shrinkage as well as having increased flexural and tensile strength as a basecoat stucco. As a part of a system, SPEC MIX FBC successfully passed the rigorous requirements of ICC AC11 Acceptance Criteria for Cementitious Wall Coatings, as reflected in Intertek code compliance research report CCRR 0231. SPEC MIX FBC is flexible in its application and when used as a One Coat Stucco, it will reduce labor and scaffolding time and increase your efficiencies by reducing installation costs by as much as 50 percent. The physical properties and the workability of SPEC MIX FBC stucco, coupled with increased productivity using our silo systems ensures maximum system performance delivering material that’s ready when you are.

The quality, workability and durability standards for SPEC MIX Fiber Base Coat stucco starts with the special sand specification we demand. Only SPEC MIX utilizes an optimized sand gradation that combines calculated percentages of masonry sand and concrete sand to achieve an optimal gradation as show in the graphs and table to the right. To ensure the FBC stucco made from every production facility is topquality, the aggregates from each SPEC MIX plant are analyzed and documented based on particle shape, composition, and gradation. Then the specific properties of the cementitious materials, special additives and fibers are analyzed to determine the proportions of each needed for the final mix design. This gives SPEC MIX the particular advantage of providing superior quality SPEC MIX FBC with minimal shipping costs compared to single or regional plant locations. As a result, the finished product can be hand troweled, spray applied, and finished by applicators with extreme efficiency while constructing a wall with shear strength, fire ratings, and toughness equivalent to conventional Three-Coat stucco systems. To minimize shrinkage cracks of SPEC MIX FBC stucco, our engineers and lab technicians performed extensive field testing to verify this specialized sand gradation and formulation would outperform other stuccos—especially field-mixed stucco.
Estimated Yields
Package WeightFBC ThicknessCoverage
80 lb (36.2 kg)3/8" (9.5 mm)20 - 24 ft² (1.8 to 2.2 m²)
80 lb (36.2 kg)1/2" (13 mm)15 - 18 ft² (1.4 to 1.7 m²)
80 lb (36.2 kg)3/4" (19 mm)10 - 12 ft² (0.9 to 1.1 m²)
3,000 lb (1,360.7 kg)3/8" (9.5 mm)750 - 900 ft² (to to 84 m²)
3,000 lb (1,360.7 kg)1/2" (13 mm)560 - 675 ft² (52 to 63 m²)
3,000 lb (1,360.7 kg)3/4" (19 mm)375 - 450 (35 to 42 m²)
Depending upon surface conditions, workmanship and technique as as waste, square foot coverage may vary. Above are only estimates for 80 lb (35.2 Kg) and 3,000 lb (1,360.7 kg) coverage rates.
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