Lambro Industries 354R Black Plastic Roof Cap 4 Inches

Product Description

The LAMBRO INDUSTRIES 354R is a 4-inch black plastic roof cap designed for ducted exhaust ventilation systems in residential and light commercial applications. It mounts at the roof termination point of a duct run, providing a weather-resistant exit for dryer exhaust, bathroom fan exhaust, kitchen range exhaust, or similar ventilation airflows. The cap features a positive-connection design that simplifies attachment to the duct collar during installation. Its plastic construction and black finish make it a practical choice for installations in areas prone to condensation, where metal caps may corrode or allow moisture intrusion over time.

This roof cap is suited for residential construction and renovation projects where a 4-inch exhaust duct terminates through the roof deck. It is commonly installed on dryer exhaust systems, bathroom ventilation fans, and energy recovery ventilator (ERV) or heat recovery ventilator (HRV) exhaust ports. The positive-connection fitting reduces the chance of separation at the duct joint, which is especially important in high-moisture or freeze-thaw environments. Each unit is individually boxed, making it easy to handle on the job site.

Key Features

• 4-inch duct opening fits standard residential exhaust duct runs
• Positive-connection design for secure, simplified duct attachment
• Black plastic construction resists corrosion in high-condensation environments
• Suitable for dryer exhaust, bath fan, and similar ventilation applications
• Individually boxed for clean job-site handling and storage

Compatibility

Designed as an OEM-style replacement or new-installation roof termination cap for 4-inch round exhaust duct systems in residential and light commercial ventilation applications.

Installation Notes

Installation is typically performed by HVAC technicians, sheet metal contractors, or licensed general contractors working under applicable mechanical codes. Ensure the duct run is fully de-energized and any associated appliance is powered off before beginning roof penetration work. Follow local building codes and manufacturer flashing requirements to maintain a watertight roof seal around the cap base. Do not operate connected exhaust equipment until the cap is fully secured and sealed.

Technical Specifications

• Duct Size: 4 inches
• Material: Plastic
• Color: Black
• Weight: 1 pound
• Package Quantity: 1
• Unit of Measure: BX

Standard Information

• Brand: LAMBRO INDUSTRIES
• Manufacturer Part Number: 354R