Full Product Manual
41
Fire Resistance
Classication with Roof Designs: P225, P227, P230, P237,
P259, P508, P510, P512, P514, P701, P711, P717, P722, P723,
P732, P734, P736, P742, P803, P814, P818, P824
• Meets ASTM D1970
• ICC-ES ESR-3121, per AC 48 Acceptance Criteria for Roof
Underlayments
• Miami-Dade County Code Report NOA
#11-0912.14
• Florida State Approval Report No. FL289-R3
• CCMC Approval No. 13671-L
in critical areas, such as along the eaves or in valleys and in
climates where severe ice dams are anticipated. Apply the
membrane to the entire roof deck for wind-driven rain protection.
Apply a new layer of Grace Ice & Water Shield
®
HT membrane
directly over the old Grace underlayment in retrot applications
following the standard membrane application procedure.
Precautions & Limitations
• Slippery when wet or covered by frost.
• Consistent with good roong practice, always wear fall protec-
tion when working on a roof deck.
• Release liners are slippery. Remove from work area immedi-
ately after membrane application.
• Do not leave permanently exposed to sunlight. Cover within
120 days.
• Place metal drip edges or wood starter shingles over the
membrane.
• Do not fold over the roof edge unless the edge is protected by a
drip edge, gutter or other ashing material.
• Do not install on the chamfered edges of wood plank.
• Do not install directly on old roof coverings.
• Certain product applications are prohibited in hot desert areas
in the southwestern United States. Check with your Grace
Construction Products representative.
• Check with the manufacturer of the metal roong system for
any special requirements when used under metal roong. Do
not install directly under roof coverings especially sensitive to
corrosion, such as zinc, without providing proper ventilation.
• Do not install under copper, Cor-Ten
®
, or zinc metal roong in
high altitudes. These roofs can reach extremely high tempera-
tures due to the low reectivity, high absorption, and high
conductivity of the metals. Use Grace Ultra™ butyl-based
underlayment for these roof types. Check with your Grace
Construction Products representative.
• Provide proper roof insulation and ventilation to help reduce
ice dams and to minimize condensation. Grace Ice & Water
Shield
®
HT underlayment is an air and vapor barrier.
• Repair holes, shmouths, tears, and damage to membrane with
a round patch of membrane extending past the damaged area 6
in. (150 mm) in all directions. If fasteners are removed leaving
holes in the membrane, they must be patched. The membrane
may not self-seal open fastener penetrations.
• Do not install fasteners through the membrane over unsup-
ported areas of the structural deck, such as over the joints
between adjacent structural panels.
• Due to its slight asphaltic odor, do not apply where the
membrane is exposed to interior living space. Refer to product
literature for more complete information.
• Not compatible with EPDM or TPO; use Grace Ultra
®
for
tie-ins (refer to Technical Letter 5, Chemical Compatibility).
• Not compatible with polysuldes, exible PVC, or high
concentrations of resin (pitch). For more information, refer to
Technical Letter 5.
Code Compliance
Grace Ice & Water Shield
®
HT underlayment meets all key code
performance requirements for self-adhered
underlayments.
• Underwriters Laboratories Inc. R13399- Class A re classica-
tion under ber-glass shingles and Class C under organic felt
shingles (per ASTM E108/UL 790)
• Underwriters Laboratories Inc. Classied Sheathing Material