NORX Cladding at the Base of a Wall: Clearance and Drainage

Why Base Clearance Matters for NORX Cladding

The primary reason for maintaining adequate clearance between NORX Cladding and the ground or adjacent surfaces is moisture management. Even though NORX composite and PVC materials are designed for exterior applications and are resistant to rot and termites, direct and prolonged contact with standing water or saturated ground can lead to several problems.

Moisture splashing up from the ground can carry dirt, debris, and even mold spores onto the cladding surface, requiring more frequent cleaning. While NORX products are low maintenance, designed for rinsing rather than painting or staining, minimizing dirt accumulation is always beneficial. Furthermore, ensuring air circulation behind the cladding, part of a rainscreen assembly, helps dissipate any moisture that might penetrate the outer layer, and this airflow is compromised if the bottom edge is too close to the ground.

Recommended Clearance Distances

This distance helps prevent splash-back from rain and snowmelt, allows for proper drainage away from the wall, and reduces the likelihood of insects or pests finding a pathway behind the cladding.

This allows any water that drains behind the cladding to exit freely and prevents the cladding from wicking moisture from the hard surface. Always consult the specific NORX installation guidelines for the chosen collection, as recommendations can vary based on the profile and intended use.

Designing for Effective Drainage

Beyond vertical clearance, the overall design of the wall base must facilitate drainage. This involves ensuring that the ground slopes away from the foundation, directing water away from the wall. For NORX Cladding, which is typically installed as part of a rainscreen system with a hidden clip on furring, an open space behind the boards allows for vertical drainage of incidental moisture.

Consider incorporating a starter strip or J-channel at the bottom of the cladding system that allows moisture to exit while providing a secure base for the first course of cladding. This component should be designed to prevent insects from entering the cavity while still allowing for ventilation and drainage. The specific details of these components will depend on the chosen NORX profile and the overall rainscreen design.

Worked Example: Calculating Base Clearance for a Patio Wall

Let's consider a hypothetical project: a 10-foot wide exterior wall clad with NORX New York Collection in Empire State dark brown, terminating above a concrete patio. The finished patio surface is 4 inches above the surrounding lawn. We need to determine the optimal cladding termination height.

This means the bottom edge of the NORX cladding should be at least 1 inch above the finished patio surface. If the patio surface is 4 inches above the lawn, the cladding's lowest point would be 5 inches above the lawn.

However, to provide an additional buffer against splash-back from the adjacent lawn area, especially during heavy rain, it would be prudent to aim for a slightly greater clearance. This offers a good balance between aesthetics and practical moisture management.

The total height of the wall section to be clad would then be measured from this chosen base clearance point up to the top termination, ensuring that the NORX boards can be cut and installed efficiently. This example highlights the need to consider all adjacent surfaces and potential water sources when determining the final base clearance.

Considerations for Different Site Conditions

Different environmental and site conditions may influence your base clearance decisions:

For areas with heavy rainfall or snow accumulation, consider increasing the minimum clearance to provide an extra margin of safety against moisture exposure. This helps ensure that the cladding remains dry, even during prolonged periods of wet weather.

In coastal environments, salt spray and wind-driven rain can be factors. A greater clearance can help reduce the impact of these elements on the lower sections of the cladding. NORX materials are designed for resistance, but minimizing direct exposure to harsh conditions is always beneficial.

If the wall is adjacent to landscaping with irrigation systems, ensure that sprinklers are directed away from the cladding. The base clearance should also account for the growth of plants, preventing them from coming into direct contact with the cladding surface, which can trap moisture and impede airflow.

For walls adjacent to driveways or walkways that are regularly cleaned with pressure washers, ensure sufficient clearance to prevent direct, high-pressure water spray from penetrating behind the cladding system.

Before you order

• Identify the finished grade or adjacent hard surface level at the base of the wall.
• Consider local climate and site conditions (e.g., heavy rain, snow, irrigation, coastal spray) to adjust clearance upwards if necessary.
• Plan for positive drainage away from the foundation (e.g., sloping grade, weep screeds).
• Select appropriate starter strips or base trim details that allow for drainage and ventilation.
• Ensure any landscape elements (soil, mulch, plants) will remain below the determined clearance level.

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

Keep planning your project