Lambro Industries 109R Round Aluminum Roof Cap 4 Inches

Product Description

The LAMBRO INDUSTRIES 109R is a round aluminum roof cap designed to terminate 4-inch diameter duct runs at the roofline. It includes an integral damper screen that blocks backdraft, debris, and pest intrusion when the ventilation system is idle. The cap features a 1.75-inch mounting flange for secure attachment to roof decking. Constructed from aluminum, it resists corrosion in outdoor exposure. This cap is installed by HVAC technicians, sheet metal contractors, and qualified mechanical contractors as part of residential or light-commercial exhaust and ventilation systems. Note: this cap is not rated or designed for dryer exhaust applications.

The 109R suits exhaust and supply ventilation terminations that require a 4-inch round duct connection at the roof penetration point. Typical applications include bathroom exhaust fans, kitchen range hoods vented through the roof, and general mechanical ventilation outlets. It is sold as a single unit and is compatible with standard 4-inch round flexible or rigid duct. It is not approved for dryer exhaust service, which requires a dedicated dryer vent cap meeting applicable code requirements.

Key Features

• Fits 4-inch diameter round duct for direct termination at the roofline
• Integral damper screen blocks backdraft, debris, and pest entry when system is off
• 1.75-inch mounting flange provides a secure attachment surface to the roof deck
• Aluminum construction resists outdoor corrosion
• Not designed for dryer exhaust use

Compatibility

Designed as an OEM-style replacement or new-installation roof cap for residential and light-commercial ventilation systems using 4-inch round duct. Not suitable for dryer exhaust applications.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified mechanical contractor following local building codes and IFGC or IMC requirements as applicable. Power down the associated fan or ventilation unit before beginning roof penetration work. Seal the flange perimeter with appropriate roofing sealant to prevent water intrusion. Do not use this cap on dryer exhaust ducts, as dryer exhaust requires a listed dryer vent termination.

Technical Specifications

• Duct Diameter: 4 inches
• Flange Size: 1.75 inches
• Shape: Round
• Material: Aluminum
• Damper Screen: Included
• Weight: 1.3 pounds
• Package Quantity: 1

Standard Information

• Brand: LAMBRO INDUSTRIES
• Manufacturer Part Number: 109R