Fiberglass FSK Duct Wrap Insulation

Johns Manville MicroLite FSK Fiberglass Duct Wrap is a thermal and acoustical insulation blanket for use as an external insulation on commercial or residential heating or air conditioning ducts. Fiberglass Duct Wrap is suitable for the exterior of rectangular or round sheet metal ducts where temperature and condensation must be controlled. FRK Duct Wrap Insulation is ideal for cooling, heating or dual temperature service ducts.

Duct Wrap insulation is 1-1/2" thick fiberglass blanket with FSK (Re-inforced Foil, aka FRK) laminate facing. It has a 3/4# density and an out of package R-Value of 5.1

Product Dimensions

Thickness: 1-1/2"
Width: 4 ft
Length: 25 ft
SF/Roll: 100 sf
Facing: FRK (Reinforced Foil)

*NOTE: FRK Tape should be purchased in conjunction with FRK Faced Fiberglass Duct Wrap

Product Installation

1. Measure the circumference or perimeter of the duct.
1. Circular Ducts add approximately 10" to duct circumference.
2. Rectangular/Square Ducts add approximately 8" do duct perimeter.
2. Install 1-5/8" Self-Stick Insulation Hangers on the bottom of horizontal duct work 18" on center (prevents sagging).
3. Cut a 2" strip of fiberglass off on one of the 4ft wide ends leaving the FRK facing (Tape Flap).
4. Use strips of tape to temporarily hold the one 4ft wide end to the duct.
5. Pull the duct wrap around the duct making sure the overlap lines up on one side of the duct (same side for all pieces).  Do not pull tight, duct wrap should not be compressed at corners.
1. Pierce the duct wrap over the insulation hangers on the bottom of the duct, install a lock washer without compressing the duct wrap, cut pin head flush with washer.
2. Tape the seam and the overlaps with FRK Insulation Tape.
3. Tape over all lock washers on the bottom of the duct to seal up the pierced/torn FRK facing.
6. Staple the overlap closed with Outward Clinching Staples
7. For leaky ducts (not sealed with Duct Sealant or Hardcast Mastic Tape) we recommend spiraling wire around all of the installed duct wrap to make sure air leaks do not blow the duct wrap off the ductwork.