Vent Cap Features & Specs

Features & Technical Specs

How it's built, what it fits, and why roofers across the country trust it on every job.

Technical Specifications

Specification	Details
Material	Polyethylene Polymer
Duct compatibility	4 inch flex or rigid duct
Minimum roof pitch	3/12 or greater
Colors available	Black and bronze
Flange size	14 x 14 inches
Height of Cap	6.78 inches
UV protection	UV additives for extended durability

Diagram of Robert's Roof Cap revealing all components.

Key Componets

Vent Cap - Impact Resistant + removable for maintenance and inspections.

Hose Clamp - Tightens securely by hand.

Duct Connector - Reduces alignment issues and speeds up bath vent and roof cap connections.

Base Flange - Oversized 4" flange creates a watertight, error-resistant seal.

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How it's made

Frequently Asked Questions

What material is Robert's Roof Cap made from?

Robert’s Roof Cap is constructed from durable, impact resistant, polyethylene polymer. It is formulated for long term rooftop performance.

Does Robert's Roof Cap work with rigid ductwork?

Yes. Robert's Roof Cap is designed for both flexible and rigid ductwork. For rigid tubes, the duct connector pushes directly through the base flange into the rigid tube for a snug fit. The hose clamp is required for rigid duct systems.

What makes the flange different from standard vent caps?

Robert's Roof Cap features an oversized base flange compared to industry-standard vent caps, which typically are 2 inches and can be a recipe for callbacks. The larger flange creates a more secure, watertight seal around the roof penetration.

Can the vent cap be removed for maintenance?

Yes. The vent cap attaches to the base flange via four locking tabs, allowing it to be removed with a claw of a hammer for inspection or maintenance without damaging the flange or shingles.

Material Testing & Verification

Independent Lab Analysis Through The Madison Group

Third-party testing by The Madison Group verified that Roberts Roof Cap vents use advanced polypropylene blends reinforced with additives for superior durability, strength, and weather resistance—proven through scientific evaluation for lasting roof protection.

For additional details or access to the full report, please contact us.

Engineered Material Solutions for Long-Life Roof Vent Performance by Michael P. Sepe, LLC

This test provides the technical foundation for selecting materials that ensure Roberts Roof Cap products resist cracking, fading, and deformation—critical for maintaining long-term roof integrity and performance. Roberts Roof Cap has conducted extensive material testing to validate these selections, ensuring proven durability and reliability in real-world conditions.