With decades of proven performance, stucco is nothing new. But as time moves on and building codes and building science evolves, specifiers must too.
Sto Corp.’s StoPowerwall® family of system-based solutions covers a real performance range, not a single fixed system – allowing specifiers to select the appropriate solution based on project requirements or conditions.
But what separates Sto’s family of stucco systems from traditional 3-coat solutions or other competitors’ solutions?
From Traditional Three-Coat Stucco to an Integrated System
Traditional stucco consists of three layers:
- Scratch Coat:
- The first layer applied over a lath. It is grooved horizontally for the next layer to latch onto.
- Brown Coat:
- The second layer that flattens and evens out the surface to a uniform thickness.
- Finish Coat:
- The final layer that provides texture and color.
StoPowerwall systems build on this traditional stucco assembly by integrating additional performance components.
- StoGuard:
- Modern codes require a water-resistive barrier (WRB).
- StoGuard serves as both the code-required WRB as well as a continuous air barrier.
- Meets 2018 IECC air barrier and IBC water-resistant barrier requirements.
- Sto DrainScreen:
- Sto DrainScreen facilitates continuous ventilation and drainage, effectively removing incidental moisture and helping preserve the integrity of the wall assembly.
- Sto Crack Defense:
- For optional crack resistance on new or existing stucco.
- It’s a glass-fiber mesh embedded in a polymer basecoat that prevents cracks by redistributing stress across the stucco.
What Makes StoPowerwall a System, Not Just a Coating
A finish coat is not a stucco system. The finish coat accomplishes only a limited set of needs for an exterior wall system such as deflection of water off the face of the cladding and curb appeal through color and texture. A system tackles the many different needs and requirements for an exterior cladding.
One requirement is moisture management. StoPowerwall systems are engineered for superior moisture management by implementing three design principles for any exterior cladding: deflection, drainage, and drying.
- Deflection: Sto high-performance coatings and finishes provide a strong, flexible outer layer that deflects water off the face of the cladding.
- Creates a more durable, easier-to-maintain surface
- Stands up to wind-driven rain and UV light degradation
- Resists algae, mildew, and mold growth
- Drainage: The Sto DrainScreen® drainage mat is an essential component of Sto’s fully engineered stucco system.
- Facilitates continuous ventilation and drainage, effectively removing incidental moisture and helping to preserve the integrity of the wall assembly.
- When combined with the StoGuard® air and water-resistive barrier, Sto DrainScreen® offers optimal protection against moisture intrusion.
- Drying: Vapor-permeable system components can support outward drying and help manage moisture that enters the wall assembly.
- Sto DrainScreen advanced cavity wall design when combined with a StoGuard vapor-permeable air and water-resistive barrier helps prevent moisture buildup inside the walls, which can lead to mold, mildew, and structural damage.
StoPowerwall is engineered and tested so all elements work together to meet today’s code and climate demands under a single source and unified warranty.
Insulated Stucco: StoPowerwall® ci
One reason to move from traditional 3-coat stucco to a system like StoPowerwall ci is that it integrates continuous air/moisture protection with continuous exterior insulation to meet advanced energy codes.
Here are some advantages of the StoPowerwall ci integrated system approach:
- Adds continuous air and water-resistive barrier and insulation to the stucco performance base, eliminating the effects of thermal bridging common with traditional insulation.
- Sto® GPS Board offers R5.0 to R10 thermal performance options to meet project requirements.
- The integration of Sto DrainScreen and Sto Gold Coat, a continuous fluid-applied, vapor-permeable air and water-resistive barrier provides water management and air leakage resistance.
Performance for Demanding Conditions
- A patent-pending Sto Fireblocking option complies with the stringent 2022 NYC Building Code by utilizing Sto Lamellas, a non-combustible fireblocking product.
- For projects in High-Velocity Hurricane Zones (HVHZ), the StoPowerwall® GMG family, utilizing a glass mat gypsum substrate, is engineered to withstand severe design pressures up to ±100 psf.
Aesthetic Range Across Systems
Performance requirements don’t have to limit design flexibility. Across the StoPowerwall family, specifiers can select from a broad range of colors, textures and finish aesthetics, from traditional stucco and plaster appearances to looks inspired by stone and concrete, as well as StoCast Brick and StoCast Wood. This allows the wall assembly to be selected for performance while maintaining flexibility in the final architectural expression.
How to Choose the Right StoPowerwall System
When it’s time to find the right system for a project, consider a few factors.
- Does the project have energy code requirements for continuous insulation or is an uninsulated stucco assembly appropriate?
- Is the project located in a high rainfall or coastal area requiring drainage?
- What is the underlying structural wall substrate type?
- Is the project in an HVHZ or high-traffic ground-level area?
Once you’ve identified the requirements, use Sto’s Wall Selector to narrow down the appropriate assemblies and confirm with Sto’s technical team to ensure the right choice for your project.
Same System Approach, Project-Matched System
The StoPowerwall family gives specifiers a range of stucco assemblies that can be matched to project-specific requirements, from traditional stucco applications and enhanced drainage to continuous insulation and specialized performance conditions. By evaluating energy requirements, climate exposure, substrate, drainage and aesthetic goals early in design, specifiers can narrow the system options and identify an assembly appropriate for the project.
To learn more about the StoPowerwall family of solutions, visit our website or download our StoPowerwall family brochure. Technical support is also available to assist with questions on your next project.