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Foil Scrim Kraft Tape, also known as FSK tape, is a type of adhesive tape commonly used in the HVAC (Heating, Ventilation, and Air Conditioning) industry. It is designed for sealing and joining insulation materials, such as fiberglass duct board, rigid board, and flexible ducting.

FSK tape consists of three layers: a backing layer made of reinforced foil, a scrim (fiberglass) layer for added strength, and a kraft paper layer on the adhesive side. The foil layer provides excellent resistance to moisture, heat, and chemicals, making it suitable for various applications.

The primary purpose of FSK tape is to create an airtight seal and provide insulation for HVAC systems. It is commonly used to seal seams and joints in ductwork, ensuring that air leakage is minimized and the system operates efficiently. The tape’s adhesive backing allows it to adhere firmly to different surfaces, including metal, insulation materials, and flexible ducting.

Foil-scrim-kraft (FSK) is a flame retardant, vapor-barrier, and it is one of the most commonly used facings in the insulation industry. High-strength foil-scrim-kraft paper all laminated together using a flame-retardant adhesive. Foil scrim kraft tape has a combined backing of aluminum foil, kraft paper, and fiberglass scrim. The combined backing properties result in a strong tape that provides a barrier against vapor.

Aluminum Foil Tape Applications:

  • Foil scrim kraft tape is used for sealing HVAC duct seams and joints where FSK is the basic insulation facing.
  • It is used for sealing and patching FSK ductwork and insulation and provides a finished look for exposed HVAC systems.

Aluminum Foil Tape Features:

  • Scrim layer bends with the primary facing providing integrity to the insulation and a strong, finished, appearance.
  • Release liner provides easy removal for efficient application on the job site.
  • High-tack synthetic rubber adhesive forms an instant bond.
  • Moisture-, mold-, and UV-resistant design.

Tape Properties:





Backing Thickness



PSTC-133 / ASTM D 3652

Total Thickness

170 Micron


PSTC-133 / ASTM D 3652

Adhesion to Steel



PSTC-101 / ASTM D 3330

Tensile Strength

120 N/25mm


PSTC-131 / ASTM D 3759




PSTC-131 / ASTM D 3759

Service Temperature

-30℃ to +80℃

-22℉ to +176℉


Applying Temperature

+10℃ to +40℃

+50℉ to +105℉


Tape Roll Size:

Finish Roll:

50mm x 50m 2” x 55yds

75mm x 50m 3” x 55yds

Log Roll: 1200mm x 50m
Jumbo Roll: 1200mm x 900m