Full Product Manual

exposed for up to 6 months. It doesn’t dry out or rot at high
temperatures. It doesn’t crack or become brittle at low tempera-
tures.
It’s slip resistant—Grace roong underlayment is formulated for
excellent skid-resistance even in wet conditions.
Suitable for use under all major roof
coverings—Grace Tri-Flex
®
mechanically-attached underlayment
can be used under shingles, tiles, slate, metal and cedar shakes.
Refer to subsequent sections for more details.
Facilitates faster and easier installation—The lighter rolls
make the one-person application fast and easy. It also means
fewer trips up the ladder and lower labor costs.
Grace technical support—Grace Tri-Flex
®
underlayment is
backed by a team of local technical support personnel that help
ensure every application goes smoothly.
Installation Guidelines
1. The roof deck must be swept clean and be smooth and dry
before installation begins.
2. Grace membrane is laid horizontally (parallel to eave), starting
at the bottom of the roof, with printed side up and with 4-inch
side laps and 6-inch end laps. Side laps run with the ow of
water in a shingling manner.
3. Grace underlayment should not be used at slopes less than
2:12, provided the slope is also acceptable to the primary roof
covering. On slopes of less than 3:12, Grace membrane should
be half-lapped a full 24 inches over the underlying course,
shingle style.
4. Grace Tri-Flex
®
underlayment is attached to the roof with
roong nails or staples both having 1-inch diameter plastic/
metal caps or other fasteners approved by Grace, spaced at 8
inches on center (oc) on both side and end laps in normal wind
zones. In high wind zones or coastal applications, double the
fastening to 4 inches oc. In all cases fasten at 24 inches oc
down the middle of the roll in the eld of the roof. Capped
nails and staples may be hand or machine applied. Nails or
staples without caps cannot be used.
5. Where seams or joints require sealant or adhesive, use a high
quality, low solvent, asbestos free plastic roong cement
meeting ASTM D4586 Type 1, Federal Spec SS-153 Type 1
(Asbestos Free). Consult your local Grace representative for
more details.
6. Install drip edge at eaves under underlayment and at rake over
underlayment.
7. Installation of the roof covering can proceed imme
Used only capped nails or capped staples.
Lay with a minimum 6 inches end lap.
Use a 4 inch side lap. Follow
printed guidelines for easy
installation.
Fasten at 24 inches oc
in the middle of the roll.
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