Grace Ice & Water Shield®
Grace Ice And Water Shield® Is the roofers preferred underlayment in extreme climate areas
such as the northern states, where winters are very harsh and 4-6 ft snow
drifts are quite common on every roof.
The leading self-adhered roofing underlayment, Grace Ice & Water Shield
offers premium leak protection for sloped roofs in climates subject to ice
dams and wind-driven rain. It is applied to the roof deck prior to the
application of the finished roof covering, which is most often shingles but
can also be tile or metal. The membrane goes under shingles and seals around
nails that hold the shingles in place, so water that doesn't drain properly
cannot penetrate the roof. It also creates a weather-tight barrier against
wind-driven rains that cause shingles to lift and leak. Affordable and easy
to install, it provides added peace of mind for many years, even in the most
Grace Ice & Water Shield should be used in conjunction
with designs which minimize ice dam formation.
It is particularly important to provide proper insulation
and ventilation to reduce the size of ice dams and to
avoid interior condensation.
Cathedral ceilings must include
ventilation (1" Air Space) between rafters to allow for air flow to a ridge vent.
Well ventilated cold roof designs are particularly
important in alpine regions to reduce the size of ice dams
which could contribute to structural damage.
Several variables will influence the height of ice dams and
the membrane coverage required.
- Climate—The annual snow fall will affect the amount of
- Slope—On a low slope, ice dams will extend farther
inward from the roof edge.
- Overhang—A wide overhang will require more
membrane to reach the appropriate point on the roof.
- Insulation and ventilation—A very well insulated
building with a cold, well ventilated attic will have
smaller ice dams.
- Valleys—Any valleys formed by projections such as
dormers or roof direction changes are likely to trap more
snow and cause larger ice dams.
- Exposure—A northern exposure or shaded areas will
generally contribute to larger ice dams.
In General: 24" inside the exterior wall(typically 6ft
complete perimeter), 12" around every penetration, 36" in every valley,
At least 4" up wall intersections and 24" onto Roof Decking
Local building codes should be consulted for specific
While gutters may
make it easier for an ice dam to start, large dams can
occur on roofs with no gutters.
Removing snow from a roof edge or installing heat cables
may not prevent ice dam formation, but may shift the
location of the ice dam. Under certain conditions, a dam
can form at the edge of the remaining snow.
|2.25 Sq Roll
||1 Sq Roll
|Roll length||75 ft (22.9 m)
|| 36 ft (11.0 m)
|Roll width ||36 in. (914 mm)
||36 in. (914 mm)
|Roll size ||225 ft2 (20.9 m2)
|| 108 ft2 (10.4 m2)
|Packaging ||Corrugated cartons
|Roll weight ||61.4 lbs (27.9 kg)
|| 33.6 lbs (15.3 kg)