System: WBP Conventional
A traditional stucco system (scratch & brown) assembly for residential & commercial buildings complying with ASTM C926 & C150.
System Downloads & Links:
WBP Component Links:

System Overview
WBP Conventional System typical installation with minimum components
Warranted Systems & Components Drawings
System Information
System description:Western Blended Products (WBP) Conventional Systems are traditional stucco system assemblies for residential & commercial buildings. WBP Conventional systems are typically applied in a three-coat style (scratch & brown + finish), in which a cementitious basecoat such as Western 1-Kote, Western One-Pass Plaster, Top Gun Premium Plaster or Insulite Lightweight Stucco, is applied in a 3/8” thick layer (scratch), creating a mechanical key for the second 3/8” thick layer (brown) in order to receive the final 1/8” thick layer of Exterior Stucco Finish or Premium Acrylic Finish (finish). Western One-Pass Plaster may be installed in a single installation at 1/2”, 3/4” or 7/8” thick coating.
Systems Recognition:
Western Blended Products Conventional Systems are compliant with ASTM C926 & C150 and are recognized in both IBC/IRC Building Codes.
System Components.
Western Blended Products Conventional Systems may consist of following components:
-
Steel or Wood Framed Construction with an approved substrate (or open framing), Concrete or Masonry. Consult Chapter 25 - Table 2506.2 of IBC for sheathing compliance and related ASTM’s.
-
A water-resistive barrier. Weather-resistive barriers shall comply IBC with Sections 1404.2 and 2510.6, IRC Section R703.2” [AC11], or the ICC-ES Acceptance Criteria for Water-resistive Barriers (AC38).
-
Woven Wire or Metal Lath. Lath shall be regular or self-furring wire fabric lath or metal lath and shall comply with the ICC-ES Acceptance Criteria for Metal Plaster Bases (Lath) (Ac191). Consult ASTM C1063, C1032, C933 & C847 for Standard Specifications.
-
Scratch & Brown Cementitious Basecoats. Western 1-Kote, Western One-Pass Plaster, Top Gun Premium Plaster, and Insulite Lightweight Stucco may be used for the scratch & brown coats. Western 1-Kote & Top Gun Premium Plaster is available in both Concentrated & Sanded versions. Insulite Lightweight Stucco is a pre-sanded material. Consult ASTM C926 & C150 for Standard Specifications.
-
A BPS Kote, Skim Coat with embedded fibermesh - Crack-Resistant System (CRS) (optional). BPS Kote must be applied at a minimum thickness of 1/16” with an approved alkali-resistant reinforcing fibermesh fully embedded within the coating.
-
A PAF Primer Coat (optional). PAF primer may be tinted to match the desired finish.
-
A Finish Coat. Acceptable finishes for Western 1-Kote, and the products noted in the latest Western 1-Kote Evaluation Report include Western Blended Products (WBP), WBP Premium Acrylic Finishes (PAF), WBP Exterior Stucco Finishes, WBP Elastomeric Paints, and WBP PAF Specialty Products.
System Overview:
Typically, WBP Conventional Systems are stucco assemblies in which an approved water resistive barrier (if present) is installed over open framing or an approved sheathing substrate. The system may also be applied over concrete or masonry surfaces. Woven Wire or Metal Lath is then fastened to the existing framing. Two basecoat layers (scratch & brown) of Western 1-Kote, Western One-Pass Plaster, Top Gun Premium Plaster or Insulite Lightweight Stucco are then applied over the wire or lath, at a minimum thickness of 3/8” per layer. Western One-Pass Plaster may be installed in a single installation at 1/2”, 3/4” or 7/8” thick coating. An optional 1/8” thick Skim Coat of BPS Kote with embedded fibermesh may be applied over the installed scratch & brown basecoat as part of a Crack Resistant System (CRS). A variety of WBP finish coats may be applied over the installed basecoat or Crack Resistant System. All Western Blended Products Exterior Stucco Finishes: Base A & B Stucco and Paint Base Exterior Stucco Finish, as well as all Premium Acrylic Finishes (PAF) and PAF Specialty Finishes are suitable exterior finish coats for all WBP Conventional System assemblies. Please consult Table 1 in this document for all available options and warranty information.
System Limitations and Requirements:
Ensure the following is taking place before the application of the system components:
-
All components must be installed per code requirements.
-
Wood-based sheathing shall be gapped 1/4” to allow for expansion.
-
Substrates are structurally sound, free of loose materials, voids, projections or other conditions that may interfere with the installation of the components.
-
Substrates are dry, clean, free of oils, grease, efflorescence, or other liquid or solid debris.
-
There are no projections or planar irregularities greater than 1/4” within any 4' radius in the substrate.
-
Masonry or Concrete surfaces are sealed or prepared with a bonding agent prior to the application of any basecoat.
-
All penetrations & openings are properly flashed.
-
All components are stored above ground under optimal conditions, or if stored outdoors, shall be adequately covered to keep dry.
-
Components shall be installed as instructed by the manufacturer and must be in compliance with the latest Western 1-Kote Evaluation report references.
-
Components shall not be installed when surface or ambient temperatures are at or below 40°F / 4.4°C or above 100°F / 34°C.
-
Cementitious components require a minimum of forty-eight (48) hours moist curing. Environmental conditions such a heat, wind and low humidity will require additional curing.
-
Protect all installed components from freezing and inclement weather until dry.
-
Consult the latest existing codes & regulations prior to the installation of any WBP System assembly.
System Assembly Options and Warranties:
All available WBP Conventional System Assemblies are listed in the following Table. System Warranties are different and dependant upon the selected assembly. Contact WBP for more information.
