4BVF – DuraVent 4-Inch Adjustable B-Vent Roof Flashing

4BVF DuraVent Adjustable Roof Flashing

4BVF by DuraVent is an adjustable roof flashing designed for compatible 4-inch Type B gas vent systems. It creates a properly formed transition around the vent pipe where the system passes through a compatible roof.

This flashing accommodates roof pitches ranging from 0/12 through 6/12. Its adjustable design allows it to fit several common roof slopes while helping direct rainwater away from the vent penetration when correctly integrated with the roofing material.

4BVF Adjustable Roof-Pitch Design

The 4BVF is designed for roofs with pitches from flat or 0/12 through a maximum slope of 6/12. A 6/12 slope corresponds to an angle of approximately 26.57 degrees.

Before ordering, confirm the actual roof pitch and the diameter of the installed vent system. The flashing must match the vent product line, nominal pipe size and roof configuration.

The adjustable collar should be positioned carefully around the vent pipe without crushing, puncturing or placing lateral pressure on the vent. Correct alignment helps maintain required vent clearances and supports a weather-resistant roof penetration.

Compatible 4-Inch Type B Vent Systems

The 4BVF is intended for compatible 4-inch DuraVent Type B gas vent components. It should not be selected solely because another pipe has the same nominal diameter.

Different venting systems may use different exterior dimensions, clearances and listing requirements. Combining incompatible products may prevent proper installation and affect the safety or weather resistance of the completed system.

Confirm compatibility using current DuraVent documentation before purchasing. A complete roof termination may also require additional pipe sections, a storm collar, supports and an approved Type B termination cap.

Durable Metal Construction

The 4BVF uses aluminum and galvanized steel components. The metal construction provides a durable base that can be integrated with compatible roofing materials using appropriate installation practices.

The flashing measures approximately 17.5 inches wide by 17.625 inches high, with an additional listed dimension of approximately 8.5 inches. Its approximate weight is 1.99 pounds.

This product is identified as UL Listed when used as intended within a compatible DuraVent system. Installation must follow the manufacturer’s current instructions to preserve the integrity of the listed assembly.

Protection Around Roof Penetrations

The primary purpose of the 4BVF is to help manage water around the point where a Type B vent passes through the roof. The flashing base must be correctly layered with shingles or other approved roofing materials so water flows over and away from the opening.

Roofing cement or sealant alone should not be treated as a substitute for correct flashing integration. The exact installation method depends on the roof material, slope, local climate and manufacturer instructions.

A compatible storm collar may be required above the flashing. The collar and approved sealant help reduce water entry through the space surrounding the vent pipe.

Professional Installation Required

The 4BVF should be installed by a qualified professional familiar with roofing and Type B gas vent systems. The installer must confirm the vent size, roof pitch, required clearances, flashing placement and complete termination assembly.

The roof opening should be only as large as necessary to install the listed vent system while maintaining all required clearances from combustible materials. Wood framing, insulation, wiring and roofing components must not interfere with these clearances.

The flashing must be positioned so that the vent remains vertical and adequately supported. It should not be used to support the weight of the complete vent system unless specifically permitted by the manufacturer.

Weatherproofing Considerations

Correct shingle placement and flashing integration are essential for limiting water intrusion. The upper portion of the base is generally positioned beneath the roofing material, while the lower portion directs water over the finished roof surface.

The exact technique varies according to roof construction. Tile, metal, membrane and asphalt-shingle roofs may require different accessories or installation procedures. Confirm that this flashing is suitable for the specific roofing material.

Do not cut, drill or reshape the 4BVF unless expressly permitted by DuraVent instructions. Unapproved modifications may weaken the component, damage its protective finish or affect the product listing.

Inspection and Maintenance

Inspect the roof flashing periodically and after severe weather. Look for loose fasteners, lifted roofing material, damaged sealant, corrosion or openings that could allow water to enter.

Also inspect the storm collar, termination cap and accessible vent connections. Any sign of water entry, movement or physical damage should be evaluated and corrected promptly by a qualified professional.

The complete gas vent system should be inspected along with the connected appliance. Carbon monoxide alarms should also be installed and maintained according to applicable requirements and manufacturer instructions.

Product Specifications

• Manufacturer: DuraVent
• Model: 4BVF
• Product type: Adjustable B-Vent roof flashing
• Compatible nominal vent size: 4 inches
• Roof-pitch range: 0/12 through 6/12
• Maximum listed pitch angle: Approximately 26.57 degrees
• Approximate width: 17.5 inches
• Approximate height: 17.625 inches
• Additional listed dimension: 8.5 inches
• Approximate weight: 1.99 pounds
• Construction: Aluminum and galvanized steel components
• Approval: UL Listed
• Country of origin: USA

Product and Installation Resources

Browse additional Type B venting and installation supplies from Xpress Supply. Review the official DuraVent Type B Gas Vent information before installation.

Choose the 4BVF when a compatible 4-inch DuraVent Type B system requires adjustable roof flashing for a pitch between 0/12 and 6/12. Confirm the vent system, roof pitch, roofing material and installation requirements before ordering.