Conventional stucco, a time-honored exterior wall finish, has graced buildings for centuries with its distinctive texture and durability. However, in the face of modern construction demands and evolving climate conditions, conventional stucco faces increasing challenges. This is a story about those challenges, particularly with improper application, and the crucial need for a well-trained workforce to ensure the longevity of this valuable trade.

A Legacy of Durability

Conventional stucco is a cementitious mixture typically composed of Portland cement, Lime, sand, and water, often reinforced with metal lath. Its history can be traced back to ancient civilizations, where it was used to protect and beautify structures. Traditional stucco has been praised for its:

• Durability: When properly applied, stucco can withstand harsh weather conditions.
• Design Versatility: Stucco can be textured and colored to achieve a wide range of aesthetic effects.
• Fire Resistance: Its cement composition provides a degree of fire protection.

The Challenges of Today

Despite its inherent advantages, conventional stucco faces several challenges in today's construction landscape:

• Moisture Intrusion: This is a critical issue. Conventional stucco is porous, and if not correctly installed with proper weather resistant barrier and flashing, water can penetrate the system, leading to:
  • Wood rot
  • Mold growth
  • Structural damage
• Cracking: Stucco is susceptible to cracking due to:
  • Settlement of the building
  • Thermal expansion and contraction
  • Improper mixing or curing
  • Structural movement
• Improper Application: A significant factor in stucco failures is poor workmanship. Common issues include:
  • Incorrect mixing ratios
  • Inadequate curing time between coats
  • Insufficient thickness
  • Improper lath installation
• Lack of Trained Workforce: The number of skilled plasterers is declining, leading to a shortage of qualified professionals who can install stucco correctly. This shortage is exacerbated by:
  • Limited vocational training programs
  • Lack of industry recognition for the trade
  • Competition from other trades
  • Demand on workforce

The Importance of Proper Application

The longevity and performance of conventional stucco depend heavily on proper application. Each step of the installation process is crucial:

1. Substrate Preparation: The underlying surface must be clean, sound, and properly prepared to receive the stucco.
2. Lath Installation: Metal lath and Stucco Wire provides a base for the stucco and must be securely fastened to the structure. This is a common mistake made by lathers and Stucco applicators alike. Fasteners should be applied in a 4 by 4 square pattern on the wire, every second nail or staple shall be fastened into a structural stud, unless specified by architect or engineer for a higher standard.
3. Application Layers: Stucco is typically applied in two to three coats:
   • Scratch Coat: Provides adhesion to the lath.
   • Brown or Double Coat: Creates a level surface.
   • Finish Coat: Provides the desired texture and color.
4. Curing: Each coat must be properly cured to achieve its full strength and minimize cracking. Curing times range from 7-28 days depending on the areas climate and warranty specifications.
5. Flashing and Detailing: Proper flashing around windows, doors, and other penetrations is essential to prevent water intrusion. Kickout or Diverter flashings at roofed gable ends if not installed by the roofer must be addressed by the Stucco Contractor before application.

Ensuring the Longevity of the Trade

To ensure the continued use of conventional stucco and address its challenges, the construction industry needs to invest in:

• Comprehensive Training Programs: Apprenticeship programs and vocational schools must provide in-depth training in traditional and modern stucco application techniques.
• Industry Standards and Certifications: Establishing clear standards and certifications for stucco installers will ensure quality workmanship and enhance credibility.
• Code Enforcement: Building codes must be strictly enforced to ensure the proper installation of stucco and prevent defects.
• Continuing Education: Ongoing training for experienced plasterers will help them stay up-to-date with new materials and techniques.
• Promoting the Trade: Active efforts to promote the plastering trade as a viable and rewarding career can attract more young people to this field.

By addressing these issues, the construction industry can ensure that conventional stucco remains a valuable and durable cladding solution for generations to come.