Understanding the Rainscreen Principle
A rainscreen assembly creates a ventilated air space, or drainage cavity, between the exterior cladding and the underlying weather barrier. This cavity allows any moisture that penetrates the cladding to drain downwards and away, while also promoting airflow to dry out the wall structure. It's a critical strategy for managing bulk water, especially in regions prone to heavy rain or high humidity.
Unlike traditional siding that relies solely on the outer layer to shed water, a rainscreen acknowledges that some water will inevitably get behind the cladding. By providing a clear path for drainage and drying, it helps prevent moisture accumulation, which can lead to rot, mold, and other moisture-related issues within the wall assembly.
Key Components of a NORX Rainscreen Assembly
A complete NORX cladding rainscreen assembly involves several layers, each serving a distinct purpose:
1. **Structural Sheathing:** The base layer, typically plywood or OSB, providing structural rigidity.
2. **Weather-Resistive Barrier (WRB):** Applied over the sheathing, this material acts as the primary defense against water penetration. It must be continuous and properly flashed around openings.
For NORX cladding, the hidden clip system typically mounts to furring.
4. **NORX Cladding:** The exterior finish layer, providing aesthetic appeal and initial protection against weather. NORX offers various collections like Paris, Rio, and London, in composite or PVC (Barcelona Collection), all designed for exterior application.
Each component plays a vital role in the overall performance, and proper installation of each layer is critical for the system's success.
The Drainage Cavity: Ventilation and Drying
The drainage cavity is fundamental to a rainscreen. For NORX cladding, this cavity is typically established by installing furring strips vertically or horizontally over the weather barrier, depending on the desired cladding orientation. The NORX hidden clip system then attaches to these furring strips. This creates a continuous air space behind the cladding.
Adequate ventilation within this cavity is crucial. It helps to equalize pressure across the cladding, reducing the driving force of wind-driven rain, and facilitates the drying of any moisture that enters the cavity. The width of the drainage cavity is an important design consideration, often specified by local building practices or manufacturer recommendations.
Weather-Resistive Barrier (WRB): The Last Line of Defense
The weather-resistive barrier (WRB) is the critical layer that prevents water from reaching the structural sheathing. It is installed directly over the sheathing, beneath the furring strips that support the NORX cladding. The WRB must be robust, continuous, and properly integrated with flashing around windows, doors, and other penetrations.
Choosing the right WRB is important. Options include house wraps, building felts, or fluid-applied membranes. Regardless of the type, ensure it is compatible with the overall wall assembly and local building codes. Its primary function is to shed any water that bypasses the cladding and drains through the air cavity.
Worked Example: NORX London Collection Rainscreen Wall
Consider a hypothetical 10-foot by 20-foot exterior wall section on a new construction project, to be clad with NORX London Collection wide slat panels in the Big Ben color. The goal is to implement a rainscreen system.
**1. Sheathing:** The wall is framed with standard OSB sheathing.
**2. Weather-Resistive Barrier:** A continuous, self-adhered WRB membrane is applied over the OSB, with all seams and penetrations properly taped and flashed according to manufacturer specifications.
**3. Furring Strips:** Vertical furring strips (e.g., 1x3 pressure-treated lumber) are installed over the WRB, spaced to align with the NORX hidden clip system. This creates a nominal 3/4-inch drainage cavity. Starter strips and insect screens are installed at the bottom of the wall to ensure proper drainage and ventilation while preventing pest entry.
**4. NORX Cladding Installation:** NORX London Collection panels are then installed horizontally, attaching to the furring strips using the specified hidden clips. The clips ensure the panels are securely fastened while maintaining the integrity of the drainage plane. Proper detailing is applied around windows and doors, integrating the cladding with the flashing system to direct water out and away from the wall.
This assembly ensures that any moisture that might penetrate the NORX cladding is managed by the drainage cavity and the WRB, protecting the building structure over time. The London Collection's wide slat profile offers a modern aesthetic while benefiting from this robust wall system.
NORX cladding is available in various collections, including Paris, Rio, Rome, Los Angeles, New York (all composite), and Barcelona (PVC). Each offers distinct colors and profiles, but the underlying rainscreen principles remain consistent for exterior applications.
Before you order
- Confirm local building codes and specific rainscreen requirements for your region.
- Select a weather-resistive barrier (WRB) compatible with your sheathing and climate conditions.
- Determine the appropriate depth and configuration of the drainage cavity (e.g., furring strip dimensions).
- Plan for ventilation at the top and bottom of the rainscreen cavity, including insect screens.
- Detail all window, door, and penetration flashing to integrate seamlessly with the WRB and drainage plane.
- Choose the NORX cladding collection (e.g., London, Paris, Barcelona) and profile suitable for your aesthetic and performance goals.
- Ensure the chosen NORX fastening system (hidden clips) is correctly installed onto the furring strips.
- Consider the long-term maintenance implications for the entire wall assembly, not just the cladding surface.
Confirm installation details, approved uses and warranty terms in the current instructions for the exact product and profile. Your installer should verify the substrate, structure and applicable project requirements.
Questions to help you decide
Why is a rainscreen important for NORX cladding?
A rainscreen assembly with NORX cladding helps manage moisture by creating a ventilated air space behind the exterior panels. This allows any water that penetrates the cladding to drain away and promotes airflow to dry out the wall, protecting the underlying structure from moisture damage, rot, and mold. It enhances the durability and longevity of the entire wall system.
What is the typical thickness of a drainage cavity for NORX cladding?
The typical thickness of a drainage cavity for NORX cladding, when using furring strips, is often around 3/4 inch to 1 inch. This dimension is usually determined by the thickness of the furring strips used (e.g., 1x3 lumber). Always consult local building codes and NORX installation guidelines for specific recommendations, as requirements can vary.
Can NORX cladding be installed directly over sheathing without a rainscreen?
While NORX cladding provides an exterior finish, for most exterior wall applications, especially in areas with significant rainfall or humidity, a rainscreen assembly is a recommended best practice. Installing cladding directly over sheathing without a drainage cavity can trap moisture, potentially leading to issues. Always follow manufacturer installation instructions and adhere to local building codes, which may mandate rainscreen systems.
Plan Your NORX Rainscreen Cladding Project
Ready to specify NORX cladding for a rainscreen assembly? Request a material quote with your project dimensions, exact NORX profile, and ZIP code. We can confirm current availability and service options for your project.
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