Posted by Spycor Building on Dec 22nd 2025
In the competitive landscape of commercial construction, architectural innovation often pushes the boundaries of building envelope design. One of the most striking trends is the use of open-joint cladding—a system that offers unparalleled depth and modern aesthetics but presents a significant challenge: the underlying structure is permanently exposed to wind-driven rain, snow, and punishing UV radiation.
To maintain structural integrity while achieving these design goals, professionals require a specialized water-resistive barrier (WRB). DELTA®-FASSADE S is engineered specifically for this purpose, providing a high-performance secondary defense that ensures the building envelope remains airtight, watertight, and durable for the long term.
The Challenge of Open-Joint Cladding Systems
Open-joint cladding systems, such as those utilizing fiber cement, metal, or high-pressure laminates (HPL) like Trespa® or Swisspearl®, feature intentional gaps between panels. These joints—often up to 2” (50 mm) wide—enhance ventilation and create a sophisticated "shadow line" effect. However, these same gaps allow UV light and bulk water to reach the insulation and the weather-resistive barrier.
Standard housewraps or WRBs are not designed for this level of exposure. Without a UV-stable membrane, the barrier will eventually degrade, crack, and fail, leading to catastrophic moisture infiltration and mold growth within the wall cavity.
Why DELTA®-FASSADE S is the Standard
for Commercial Envelopes
DELTA®-FASSADE S is a premium, UV-stable water-resistive barrier designed to survive where others fail. It consists of a highly tear-resistant polyester substrate with a special, highly UV-stabilized acrylic coating.
1. Unmatched UV Stability
The primary differentiator for DELTA®-FASSADE S is its ability to withstand permanent UV exposure. It is the only membrane on the market that allows for up to 50% open area in cladding systems with joints up to 2 inches wide. While traditional barriers would crumble under these conditions, the acrylic coating on DELTA®-FASSADE S ensures the membrane remains flexible and intact for decades.
2. Advanced Moisture Management
Effective moisture management in a building envelope requires two things: keeping liquid water out and letting water vapor escape.
-
Watertight Protection: It acts as a durable drainage plane, channeling wind-driven rain and snow to the outside of the structure before it can reach the sheathing.
-
High Vapor Permeability: With a rating of over 300 perms, it is one of the most breathable membranes in the industry. This allows moisture trapped within the wall cavity to escape swiftly, preventing the "sick building syndrome" often caused by trapped condensation.
3. Enhancing Energy Efficiency and Airtightness
As a certified air barrier, DELTA®-FASSADE S contributes significantly to a building's energy performance. By preventing uncontrolled air leakage, it helps maintain a stable interior climate and reduces the load on HVAC systems, making it an essential component for projects seeking LEED® certification.
Technical Specifications and Compliance
For architects and specifiers, performance data is non-negotiable. DELTA®-FASSADE S meets the most rigorous standards for commercial construction:
-
Flame Spread: NFPA Class A; IBC Class A (ASTM E84).
-
NFPA 285 Compliant: Safe for use in many types of non-combustible commercial wall assemblies.
-
Air Permeance: 0.9 l/(s x m²) @ 75 Pa (ASTM E2178).
-
Temperature Range: Remains stable from -40 °F to +176 °F (-40 °C to +80 °C).
Best Practices for Installing DELTA®-
FASSADE S
The performance of a building envelope is only as good as its installation. To ensure a continuous air and water barrier, follow these industry-best practices:
-
Substrate Preparation: Ensure the sheathing (OSB, plywood, or exterior gypsum) is clean and dry.
-
Strategic Overlapping: Start at the bottom of the wall to create a "shingle" effect. Horizontal seams should overlap by at least 4 inches, and vertical seams by 6 inches.
-
Use Compatible Accessories: Only use UV-stable accessories like DELTA®-FASSADE TAPE and DELTA®-FASSADE FLASHING. Standard tapes will fail behind open joints. For liquid flashing around windows and doors, use DELTA®-LFS 100% silicone.
-
Avoid Surfactants: Do not use sealants or chemicals containing surfactants, as they can compromise the water-hold-out properties of the membrane.
Aesthetic Versatility: The "Blackout"
Effect
Beyond performance, DELTA®-FASSADE S provides an aesthetic advantage. The membrane is a deep matte black, which creates a clean, uniform background behind open-joint cladding. This eliminates the "distraction" of seeing insulation or shiny silver foil through the gaps, ensuring the architect's vision is the focal point of the building.
Protecting the Future of Architecture
Open-joint cladding is the future of modern commercial facades, but it requires a specialized approach to weatherproofing. By choosing DELTA®-FASSADE S, developers and contractors are investing in a system that offers the highest level of UV protection, breathability, and airtightness available today.
Order Now at spycorbuilding.com to get the best pricing and expert support for your next commercial project.
Frequently Asked Questions (FAQ)
Can DELTA®-FASSADE S be used with any open-joint cladding?
Yes, it is compatible with most premium systems, including fiber cement, metal panels, and HPL (High-Pressure Laminate) systems such as Trespa®, Swisspearl®, and Fundermax®. It is designed for joints up to 2” (50 mm) wide.
What is the difference between DELTA®-FASSADE S and DELTA®-FASSADE S PLUS?
DELTA®-FASSADE S PLUS features an integrated self-adhesive border, which allows for faster installation and more secure, windproof laps without the need for additional tape on every horizontal seam.
How long can the membrane be left exposed before the cladding is installed?
While it is designed for permanent UV exposure once the cladding is in place, it is recommended to install the final cladding within a reasonable timeframe (typically 6 months) to protect the membrane from physical damage during construction.
Is DELTA®-FASSADE S vapor permeable?
Yes. It has an industry-leading vapor permeance of over 300 perms, which is critical for allowing the wall assembly to dry out and preventing mold growth.
Where can I buy DELTA®-FASSADE S?
You can purchase the full range of DELTA® products, including the specialized UV-stable tapes and flashings, at
