HydraShell Max

HydraShell MAX

Synthetic Roof Underlayment

The reliable underlayment choice with a 30-year limited warranty.

  • Won’t wrinkle or absorb water
  • Stays flexible in cold weather
  • 25 times stronger than #15 felt
  • 12 times stronger than #30 felt
  • More coverage per roll
  • Less weight per roll
  • Requires fewer fasteners
  • Cool Gray surface to reduce heat build-up
  • 90-day UV exposure rating
  • Class A fire rating
  • Use under asphalt shingles, synthetic shingles, cedar shakes, and metal
  • Miami-Dade County Code approved
  • Made in the USA

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HydraShell Max


When you need a high-strength, lightweight synthetic roof underlayment, HydraShell™ MAX is the choice for you. Manufactured from 100% synthetic materials, HydraShell MAX has a four-layer construction making it 25 times stronger than #15 felt and 12 times stronger than #30 felt. It requires significantly few fasteners, and provides a tough, durable deck cover. Less weight per roll and a non-woven walking surface makes for a simple and easy installation. Backed by a 30 year limited warranty, HydraShell MAX is designed for use under all types of roofing materials including asphalt shingles, synthetic shingles, cedar shakes, and metal.


Roll Dimensions: 40”/300’
Permeability: 0.1 perms
Water Transmission: Pass
Tear Strength: 33 lbs MD/24 lbs CD
Tensile Strength: 95 lbs MD/85 lbs CD
Burst Strength: 160 psi
Elongation: 20%
Weight Per Square: 1.96 lbs
Nominal Thickness: 6.2 mils
Temp. Range (Internal): -70° F to 240° F

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Easy Installation

HyrdraShell MAX is lighter than felt so its easier to handle. It offers more coverage per roll, and is pre-printed with a nailing pattern for easier installation.

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.