Description:
Plastic Cement is a specially manufactured hydraulic cement designed for plastering applications. The product complies with ASTM C1328 requirements for plastic (stucco) cement.

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When combined with plaster sand and potable water, Plastic Cement produces portland cement plaster suitable for scratch and brown coat applications in exterior stucco assemblies.

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Plastic Cement contains workability-enhancing components that improve board life, plasticity, and pumpability compared to standard portland cement, making it well-suited for vertical plastering applications.

Plastic Cement must be combined with plaster sand and water to produce plaster suitable for field application in accordance with ASTM C926.

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Packaging:
Product is packaged in 94 lb / 42.6 kg bags.
35 bags per pallet.

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Benefits:

• ASTM C1328 compliant plastic (stucco) cement

• Improved plasticity and workability for plaster applications

• Extended board life compared to standard portland cement

• Suitable for hand or machine-applied plaster

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Coverage:
Coverage of plaster produced with Plastic Cement will vary depending on plaster mix proportions, sand gradation, and application thickness.

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Plastic cement plaster is produced by combining cement with plaster sand and water in accordance with ASTM C926 proportion requirements. Final yield and coverage are determined by the selected mix design and jobsite batching procedures.

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Coverage may also vary depending on substrate condition, application method and waste.

 

Mixing:
Plastic Cement shall be mixed with plaster sand and potable water to produce portland cement plaster.

 

Plaster sand shall comply with ASTM C144 or ASTM C897.

 

Typical plaster mixing procedure:

• Add plaster sand to a clean mortar mixer.

• Add Plastic Cement.

• Dry blend materials until uniformly mixed.

• Add potable water to achieve a workable plaster consistency.

• Mix until the plaster is uniform and suitable for application.

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Final mix proportions shall comply with ASTM C926 plaster requirements.

 

Application:
Plaster produced using Plastic Cement shall be applied in accordance with ASTM C926.

 

Typical applications include:

• Scratch coat plaster

• Brown coat plaster

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Application may be performed using standard plastering methods including:

• Hawk and trowel

• Pump or spray application

• Rod and darby methods

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Substrate preparation, lath installation, plaster thickness, and control joint placement shall comply with ASTM C926 and ASTM C1063.

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Curing:
The product requires a minimum of forty-eight (48) hours moist curing. Environmental conditions such as heat, wind and low humidity will require additional curing.

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Finishing:
Plastic Cement is used to produce basecoat plaster and is not intended as a finish coat material.

After proper curing of the basecoat plaster, compatible stucco finish materials may be applied in accordance with manufacturer recommendations.

Limitations:

• Plastic Cement is a plaster cement binder and must be combined with plaster sand and water to produce plaster.

• Not a ready-to-use stucco basecoat product.

• Performance of plaster produced with this material depends on proper jobsite batching, sand quality, and application procedures.

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

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

• 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. 

 

Storage:
Plastic Cement 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 C1328 – Plastic (Stucco) Cement

• ASTM C926 – Application of Portland Cement-Based Plaster

• ASTM C1063 – Installation of Lathing and Furring to Receive Portland Cement-Based Plaster

• ASTM C144 – Aggregate for Masonry Mortar

• ASTM C897 – Aggregate for Job-Mixed 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.