Vycor Ice & Water Shield HT

CertainTeed Vycor Ice & Water Shield HT is a high temperature self-adhered roofing underlayment. It combines a proprietary rubberized asphalt adhesive with a polymeric film that has ultraviolet barrier properties. The HT version is the variant for metal roofs and other high temperature assemblies, and it withstands temperatures up to 260 degrees F (127 degrees C).

The membrane is an underlayment for sloped roofs, used to resist water penetration from water back-up behind ice dams and from wind-driven rain. It also protects valleys, skylights, protrusions and other flashing areas. It is used under standing seam metal, slate, tile, cedar shakes, metal and conventional asphalt shingles.

The membrane bonds to the deck without heat or added adhesives. The product SKU is prfa-666.

The rubberized asphalt surface is backed by a foldless release paper. A RIPCORD embedded in the adhesive gives a split release on demand for detail areas. The membrane has a slip resistant embossed surface.

The membrane contains recycled ground rubber tires. It resists attack from fungus and bacteria. Membrane color is gray-black.

Two roll sizes are published, both 36 in (914 mm) wide and packed in corrugated cartons.

• 75 ft (22.9 m) roll: 225 ft2 (20.9 m2), 61.4 lbs (27.9 kg), 35 rolls per pallet
• 66.6 ft (20.2 m) roll: 200 ft2 (18.6 m2), 56 lbs (25.4 kg), 35 rolls per pallet

• Thickness: 40 mil (1.02 mm), ASTM D3767 method A
• Tensile strength: MD 25 lbf/in, CD 25 lbf/in, ASTM D412 (Die C modified)
• Elongation: 250%, ASTM D412 (Die C modified)
• Low temperature flexibility: unaffected at -20 degrees F (-29 degrees C), ASTM D1970
• Adhesion to plywood: 3.0 lbs/in width (525 N/m), ASTM D903
• Permeance (max): 0.05 perms (2.9 ng/m2 s Pa), ASTM E96
• Installed material weight (max): 0.22 lb/ft2 (1.3 kg/m2), ASTM D461

The membrane is installed directly on a clean, dry, continuous structural deck of plywood, wood composition, wood plank, metal, concrete or gypsum sheathing. Concrete, masonry and DensGlass Gold are primed with Perm-A-Barrier WB Primer at 250-350 ft2/gal (6-8 m2/L). Application is at 40 degrees F (5 degrees C) or higher.

Pieces of 10-15 ft (3-5 m) are cut and loosely re-rolled, and the liner is peeled back 1-2 ft (300-600 mm) at a time. Side laps are at least 3.5 in. (90 mm), set by aligning the liner edge with the dashed line printed on the membrane, and end laps are at least 6 in. (150 mm). Work runs from the low point up the roof, with eave membrane first and valley membrane lapped over it.

The membrane can stay exposed for up to 120 days before the final roof covering goes on. For retrofit, a new layer of the HT membrane goes directly over old CertainTeed self-adhered underlayment, except CertainTeed granular underlayment. A double layer can be used at eaves and valleys where severe ice dams are expected.

• It is not installed under copper, COR-TEN or zinc metal roofing at high altitudes; Vycor Ultra butyl underlayment is named for those roof types.
• It is not installed directly under roof coverings especially sensitive to corrosion, such as zinc, without proper ventilation.
• The membrane is not compatible with EPDM or TPO, and Vycor Ultra is named for tie-ins.
• It is not compatible with polysulfides, flexible PVC or high concentrations of resin (pitch) in some wood plank decks.
• It is an air and vapor barrier and is not applied where exposed to interior living space, because of a slight asphaltic odor.
• The HT membrane is stored in original unopened packaging between 40 and 90 degrees F (5-32 degrees C) and used within one year of manufacture.

• Meets ASTM D1970
• Meets AC 48
• Meets AC 188
• Florida State Product Approval FL-298 including HVHZ
• Texas Department of Insurance Product Evaluation Listed
• Underwriters Laboratories Classified Sheathing Material Fire Resistance Classification with roof designs P225, P227, P230, P237, P259, P508, P510, P512, P514, P560, P701, P711, P717, P722, P723, P732, P734, P753
• Underwriters Laboratories R13399, UL 790/ASTM E108 Class A under fiber-glass shingles and Class C under organic felt shingles