HydraShell™ MaxGrip

Hydrashell® Max-Grip is a high-performance, self-adhesive roofing underlayment engineered for superior protection against ice and water intrusion. Built with a durable glass mat carrier and coated with a premium blend of SBS polymers, asphalt, and additives, it delivers the perfect balance of flexibility and toughness. Its sanded top surface allows for confident foot traction during installation, while the underside features a highly adhesive asphalt layer protected by a silicon-based release film for a clean, efficient application.

Benefits

Leak-Free Protection – Its seamless design helps prevent roof leaks and water intrusion, protecting the home from moisture damage.
Dual-Purpose Venting – Designed to vent both bathroom fans and dryers through the roof, reducing the need for multiple roof penetrations.
Improved Airflow – Helps efficiently remove moisture, heat, lint, and odors from the home.
Built-In Flapper – The flapper helps prevent backdrafts, outside air intrusion, pests, and debris from entering the vent system.
Installation Flexibility – Available with or without an attached collar to fit different installation needs and duct connections.
Cleaner Roof Appearance – The low-profile, seamless construction provides a more finished and professional look on the roof.
Durability – Made to withstand outdoor weather conditions while maintaining reliable performance over time.
Reduced Moisture Problems – Properly exhausting bathroom humidity can help reduce mold, mildew, and condensation buildup inside the home.

VIEW SPECS

Maximum Load (ASTM D2523): 4.4 KN / m

Elongation at Break (ASTM D2523): 10%

Adhesion to Plywood at 4°C (ASTM D903): 0.92 KG/30.5 cm

Adhesion to Plywood at 23℃ (ASTM D903): 5.44 kg/30.5 cm

Thermal Stability (ASTM D1204): 3 mm

Flexibility Temperature (ASTM D1970): -29℃

Tear Resistance (ASTM D4073): 89 N

Waterproof Integrity of Lap Seam (ASTM D1970): Pass

Sealability Around Nail (ASTM D7349): Pass

Moisture Vapour Permeance (ASTM E96): 5.7 ng/Pa.S.M²

Slip Resistance (ASTM D1970): Pass

How To Install

Step 1

Lay out horizontally on the eave, printed side up, with 3” horizontal laps and 6” vertical laps.

Step 2

Fasten with 1” diameter plastic cap roofing nails or staples according to pre-printed nail pattern.

ADDITIONAL RESOURCES

VENTILATION CALCULATOR

Calculate the exact amount of ventilation needed for a well-balanced system.

TECHNICAL TOOLS

Dive deep into product sheets, diagrams, and full spec breakdowns.

Roofing FAQ

Learn everything you need to know about ventilation.

HydraShell™ MaxGrip

Benefits

VIEW SPECS