Shurtape sf686-3spt Shurmastic Roll Mastic Tape 3in X 100ft

Product Description

The SHURTAPE sf686-3spt is a roll mastic tape designed for air-tight and moisture-free sealing in HVAC duct systems. Measuring 3 inches wide and 100 feet per roll, it works on Class 1 Flex Duct, sheet metal, PVC coated duct, and duct wrap vapor barriers. It is UL 181B-FX Listed, tested to UL 723 with a Flame Spread Index of 15 and Smoke Developed Index of 10, and meets SMACNA pressure classes 1/2, 1, 2, 3, 4, and 6 across Seal Classes A, B, and C. Licensed HVAC technicians and sheet metal contractors rely on this tape for both indoor and outdoor duct sealing applications.

This tape is suited for residential and light commercial HVAC ductwork installations where code-compliant sealing is required. It applies to Class 1 flexible duct connections, sheet metal seams, and PVC coated duct assemblies. The product is also approved for subgrade application on PVC coated duct, making it useful in below-grade mechanical spaces and crawlspace installations where moisture exposure is a concern. It is a practical choice wherever a single tape must handle multiple duct substrate types on the same job.

Key Features

• UL 181B-FX Listed for use on Class 1 Flex Duct
• Meets SMACNA pressure classes 1/2, 1, 2, 3, 4, and 6
• Seal Class A, B, and C rated
• FSI 15 and SDI 10 per UL 723 testing
• Approved for subgrade application on PVC coated duct
• Suitable for indoor and outdoor use on sheet metal, flex duct, PVC duct, and vapor barriers

Compatibility

Designed for use with Class 1 Flex Duct, sheet metal ductwork, PVC coated duct, and duct wrap vapor barriers in HVAC air distribution systems.

Installation Notes

This tape is installed by licensed HVAC technicians and sheet metal workers during duct fabrication or repair. Shut down the air handling system and verify zero pressure in the duct before applying tape to seams or connections. Surface should be clean and dry for proper adhesion, particularly in subgrade or high-moisture environments. Work should comply with applicable mechanical codes including SMACNA duct construction standards and local jurisdiction requirements.

Technical Specifications

• Width: 3 inches
• Roll Length: 100 feet
• Listing: UL 181B-FX
• SMACNA Pressure Classes: 1/2, 1, 2, 3, 4, 6
• Seal Classes: A, B, C
• Flame Spread Index (FSI): 15
• Smoke Developed Index (SDI): 10
• Application Environment: Indoor and outdoor, including subgrade on PVC coated duct

Standard Information

• Brand: SHURTAPE
• Manufacturer Part Number: sf686-3spt