Installation Guide
roll. Stop frequently to press the membrane in place
with heavy hand pressure. When nished with the roll
go back to the beginning, reroll and pull the remaining
release paper from the material, nishing the installation.
Consistent with good roong practice, install the
membrane such that all laps shed water. Always work
from the low point to the high point of the roof. Apply
the membrane in valleys before the membrane is
applied to the eaves. Following placement along the
eaves, continue application of the membrane up the
roof. The membrane may be installed either vertically
or horizontally.
Use smooth shank, electroplated galvanized nails for
fastening shingles. Hand nailing generally provides a
better seal than power-activated nailing. If nailing of
the membrane is necessary on steep slopes during hot
or extreme cold weather, backnail and cover the nails
by overlapping with the next sheet.
Extend the membrane on the roof deck above the
highest expected level of water back-up from ice
dams and above the highest expected level of snow
and ice on the wall sheathing on vertical side walls
(dormers) and vertical front walls for ice dam protec-
tion. Consider a double layer of membrane 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 Ultra
™
underlayment 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 protection when working on a roof deck.
• Release liners are slippery. Remove from work area
immediately after membrane application.
• Do not leave permanently exposed to sunlight.
Maximum recommended exposure is 60 days.
• Place metal drip edge or wood starter shingles over
the membrane.
• Place metal drip edges or wood starter shingles over
the membrane (refer to Technical Letter 15, Roof
Eave Application).
• 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.
• 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.
• Provide proper roof insulation and ventilation to
help reduce ice dams and to minimize condensation.
Grace Ultra
™
underlayment is a vapor barrier.
• Repair holes, shmouths, tears, and damage to
membrane with a round patch of membrane extend-
ing 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
unsupported areas of the structural deck, such as over
the joints between adjacent structural panels.
• Due to its slight rubber-like odor, do not apply where
the membrane is exposed to interior living space.
• Compatible with EPDMs (refer to Technical Letter
5, Chemical Compatibility). Also for use in tie-ins in
EPDM with other Grace underlayments.
• Not compatible with polysuldes, exible PVC or
high concentrations of resin (pitch). For more infor-
mation, refer to Technical Letter 5.
Standard Compliance
Grace Ultra
™
meets the following standards:
• ICC ESR-1677 approval according to AC-48 Accep-
tance Criteria for Self-Adhered underlayments used
as Ice Barriers
• Underwriters Laboratories, Inc. R13399 Class A re
classication under berglass shingles and Class C
under organic felt shingles
• Underwriters Laboratories, Inc. Classied Sheath-
ing Material Fire Resistance Classication Design
Numbers P225, P227, P230, P237, P259, P508, P510,
P512, P514, P701, P711, P717, P722, P723, P732,
P734, P742, P824