Description:
Base B Exterior Stucco Finish is a factory-prepared portland cement-based exterior finish coat designed for application over properly cured portland cement plaster basecoats. The product is manufactured for integrally colored stucco finishes and is compatible with conventional three-coat stucco systems, Western 1-Kote® systems, Western One-Pass® systems, and Crack Resistant System (CRS) assemblies.

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Base B is produced in multiple aggregate blends to achieve a range of architectural textures. Final appearance is dependent upon aggregate selection and field finishing technique.

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Packaging:

• Base B is packaged in 90 lb / 40.8 kg bags.

• 35 bags per pallet. 

Premixed Exterior Stucco packaging is available per regional production. Color Pak units are packaged separately for use with Base B material.

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Product Uses:
Base B is intended for use as an exterior finish coat over cured portland cement plaster basecoats:

• Conventional scratch and brown stucco systems.

• Western 1-Kote® exterior stucco systems.

• Western One-Pass® exterior stucco systems.

• Crack Resistant System (CRS) assemblies.

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Benefits:

• Factory-controlled cementitious formulation.

• Integrally colored mineral finish.

• Multiple aggregate blends for architectural texture variation.

• Compatible with hand or machine application methods.

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Coverage:
Approximately 72 square feet, 8 square yards, and 6.7 square meters @ 1/8" thickness.

Actual coverage will vary depending on aggregate blend and texture profile. Typical field yield ranges from approximately 72 to 108 square feet per 90 lb bag depending on texture selection and application method, including machine dash, skip trowel, sand float, and smooth finishes.

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Mixing:
Dry Bag Base Mixing:

• Add Base B Exterior Stucco Finish to a clean mortar mixer.

• Add approximately 1.5 to 2.0 gallons of potable water per 90 lb bag.

• Mix to a uniform consistency suitable for the selected application method. Do not retemper with additional water after initial set has begun. 

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Premixed Exterior Stucco:

• Premixed Exterior Stucco shall be mechanically mixed prior to application to ensure uniform consistency.

• Minor water adjustment may be made to achieve proper workability. Do not exceed manufacturer’s recommended water addition.

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Base + Color Pak Mixing:

• When using Base B Base material with Color Pak:

• Add Base B Base material to a clean mixer.

• Add full Color Pak contents per batching instructions.

• Dry mix thoroughly to ensure complete pigment dispersion before adding water.

• Add potable water (approximately 1.5 to 2.0 gallons per 90 lb equivalent) and mix to uniform consistency.

Incomplete blending of pigment may result in color inconsistency.

 

Application:
Basecoat plaster shall be fully cured in accordance with ASTM C926 prior to finish application.
Dampen basecoat as necessary to control suction.
Base B Exterior Stucco Finish may be applied by:

• Hand trowel application

• Hawk and trowel methods

• Spray application (machine pump)

• Spray-and-float techniques

• Dash or skip trowel methods depending on specified texture

Application thickness shall be consistent with selected texture and aggregate blend.
Application shall comply with ASTM C926 and manufacturer’s written instructions.

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Curing:
Protect finish from rapid drying, freezing, precipitation, and direct sun exposure during initial cure.
Moist curing may be required under hot, dry, or windy conditions.
Allow sufficient curing prior to application of paints or sealers when specified.
When exterior paint coatings are applied, ensure the surface pH level is neutral prior to application and follow the paint manufacturers' recommendations for pH compatibility and installation guidelines.

 

Finishing:
Base B Exterior Stucco Finish is available in the following aggregate blends:

• Coarse (16/20): Used for heavy skip trowel, sand, or dash finishes. Coarse sands add greater depth and shadowing to stucco textures.

• Medium (20): Used for medium skip troweled textures, lighter sand finishes, and Southwestern-style textures.

• Fine (20/30): Used for less noticeable aggregate finishes.

• Smooth: Used for super smooth finishes. Smooth finishes are more susceptible to visible cracking and uneven color. These characteristics must be discussed with the project owner or design authority prior to installation.

Uniform batching, consistent water measurement, and proper curing practices are essential to minimize color variation.

Field sample panels are recommended, particularly for Fine and Smooth finishes.

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Limitations:

• For exterior use only. 

• Not a waterproofing membrane.

• Does not prevent cracking caused by structural movement, substrate instability, or improper joint placement.

• Smooth finishes are more susceptible to cracking and color variation.

• Control joints shall comply with project drawings and specifications prepared by the design authority, or ASTM C1063.

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Do not apply when surface or ambient temperatures are at or below 40°F / 4.4°C or above 100°F / 38°C. Do not apply to surfaces that are contaminated with bond breakers, oils or other matter that may affect the performance of the product. Do not apply if conditions are expected to be above or below the specified temperature range within 24 hours of application. Do not add additional ingredients without specific written approval from an authorized manufacturer of Western Blended Products.

 

Storage:
Base B shall be kept indoors or if stored outdoors, shall be adequately covered to keep dry and be stored off the ground.

 

Applicable Standards, Specifications and Codes:

• ASTM C150 – Portland Cement

• ASTM C926 – Application of Portland Cement-Based Plaster

• 2024 International Building Code (IBC)

• 2024 International Residential Code (IRC)

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Conditions of Use and Limited Warranty:

Specifications for this product are based on optimal environmental conditions (70°F ambient temperature with 50% humidity) for preparation, mixing, application and curing. Specification parameters may vary as environmental conditions change. Consult the product’s Safety Data Sheet or GHS Section located on the product package for hazard identification and first aid measures. KEEP OUT OF REACH OF CHILDREN.

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Western Blended Products (WBP) warrants that its products are of merchantable quality and suitable for the general purpose for which they are intended when applied in accordance with WBP instructions. The manufacturers of WBP products do not warrant the products to be suitable for any purpose or use other than that for which they are intended. Liability under this warranty is limited to supplying new material without charge or, at the option of the manufacturer of the WBP product, refunding the purchase price. In the event of a claim under this warranty, written notice must be provided to the originating plant of the WBP product at the address shown herein. This limited warranty is issued and accepted in lieu of all other express warranties and expressly excludes liability for consequential damages. Some states do not allow the exclusion or limitation of incidental or consequential damages, or limitations on how long an implied warranty lasts; therefore, the above limitations or exclusions may not apply.