Full Product Manual

needed. In addition, Grace Ultra
™
underlayment is the appropriate
product for use under certain types of metal roofs (those employ-
ing copper, zinc, or Cor-Ten
®
panels). These metal roofs tend
to readily conduct heat to the underlayment making them more
likely to expose the membrane to high temperatures. It is up to
the contractor and specier to decide what level of performance
is required based on the guidelines provided.
Wind-Driven Rain
Sloped roofs are not waterproof. They protect structures by
shedding rain water. Storm-driven winds can cause sloped roof
coverings to lift. Rain can be easily driven under the roof cover-
ing directly to the unprotected deck where it causes leaks and
damage to the interior of the structure. Grace Ultra
™
membrane
applied beneath the sloped roof covering helps prevent wind-
driven rain from entering the structure. For wind-driven rain
protection, full coverage with Grace Ultra
™
underlayment is
recommended. Since Grace Ultra
™
underlayment is a vapor
barrier, the roof construction must allow for proper ventilation in
full roof coverage applications.
Ice Dams
For ice dam protection, Grace Ultra
™
membrane should be
adhered at the edge of the roof deck by the eaves. The membrane
should be applied to a point on the roof deck above the highest
expected ice dam. Several variables inuence the height of ice
dams and the membrane coverage required. Local building codes
should be consulted for specic requirements. Variables inuenc-
ing the height of ice dams include climate (particularly the annual
snowfall), slope, overhang, valleys, how well the structure is
insulated and ventilated, and exposure (sun vs. shade). In addition
to placement along the eaves, Grace Ultra
™
membrane can be
used to help prevent roof leaks in a handful of danger zones like
in valleys, at the rake edges, and around chimneys and skylights.
Installation Procedure
Surface Preparation
Install Grace Ultra
™
membrane directly on a clean, dry, continu-
ous structural deck. Some suitable deck materials include
plywood, wood composition, wood plank, metal, concrete,
or gypsum sheathing. For all other substrates, contact your
local Grace representative. Remove dust, dirt, loose nails, and
old roong materials. Protrusions from the deck area must be
removed. Decks shall have no voids, damaged, or unsupported
areas. Repair deck areas before installing the membrane.
Prime concrete, masonry surfaces and DensGlass Gold
®
with
Perm-A-Barrier
®
WB Primer. Prime wood composition and
gypsum sheathing with Perm-A-Barrier
®
WB Primer if adhe-
sion is found to be marginal (refer to Technical Letter 12, Use
on Oriented Strand Board (OSB) Roof Sheathing). Apply Perm-
A-Barrier
®
WB Primer at a rate of 250–350 ft
2
/gal (6–8 m
2
/L).
Priming is not required for other suitable surfaces provided that
they are clean and dry.
Membrane Installation
Apply Grace Ultra
™
membrane in fair weather when the air, roof
deck, and membrane are at temperatures of 40°F (5°C) or higher.
Apply roof covering material at temperatures of 40°F (5°C) or
higher.
Cut the membrane into 10–15 ft (3–5 m) lengths and reroll
loosely. Tack/secure the end of the roll with a nail. Peel back
1–2 ft (300–600 mm) of release liner, align the membrane, and
continue to peel the release liner from the membrane. Press the
membrane in place with heavy hand pressure. Side laps must be
a minimum of 3.5 in. (90 mm) and end laps a minimum of 6 in.
(150 mm). For valley and ridge application, peel the release liner,
center the sheet over the valley or ridge, drape, and press it in
place. Work from the center of the valley or ridge outward in each
direction and start at the low point and work up the roof.
Alternatively, starting with a full roll of membrane, unroll a
3–6 ft (1–2 m) piece of membrane leaving the release liner in
place. Align the membrane and roll in the intended direction
of membrane application. Carefully cut the release liner on
top of the roll in the cross direction being careful not to cut the
membrane. Peel back about 6 in. (150 mm) of the release liner
in the opposite direction of the intended membrane application
exposing the black adhesive. Hold the release liner with one hand
and pull the roll along the deck with the release liner, leaving the
applied membrane behind. Use the other hand to apply pressure
on the top of the
Use Grace Ultra
™
underlayment on all of these
critical areas
Confined
Rake Edge
Rake Edge
Eave
Low Slope Area
Chimney
Skylight
Valley
Eave
Ridge
Hip
Dormer
Corners
Flanged Windows
Sill
Exterior
Doors
Sill Plate
Ledger Board
Deck Joists
Grace Ultra™ Roofing Underlayment
Grace Vycor
®
Plus Flashing
Grace Vycor Deck Protector
®
Flashing
44