Instructions / Assembly
3
Roof sheathing is a plywood or OSB (oriented strandboard)
layer on top of the roof supports. If your roof has sheathing,
we recommend using standard felt paper or an ice water shield
over the sheathing.
If your roof has purlins instead of sheathing, then the maximum
purlin spacing is 24 inches on center. If your roof may be
exposed to heavy snow loads, then the purlin spacing should be
reduced to 12 inches on center.
While stored at the job site, ONDURA-9 sheets must be
covered to protect from damage that may be caused by
rainwater trapped between sheets. Do not allow stacked
sheets to get wet while stored.
ONDRUA-9 sheets are 36 inches wide and 79 inches long. We
recommend an overhang at the roof eave of 1 to 1-3/4 inches
(Note: 1-3/4 inches is the maximum overhang relave to the
edge of the roof sheathing). Measure the roof from eave to
ridge and add the overhang length to determine the total length
of coverage.
If the total length of coverage is greater than 79 inches, then
you will need a second row of ONDURA-9 sheets. The sheet
overlap from row to row should be at least 7 inches.
The slope of the roof can be calculated from measurements
of the rise and run of the roof. The rise is the vercal distance
of the ridge above the eave. The run is the horizontal distance
of the ridge from the eave. A roof slope is oen stated as the
inches of vercal rise per 12 inches of horizontal run length. The
minimum appropriate slope for an ONDURA-9 roof is a 3 inch
rise over a 12 inch run.
Always wear eye protecon when cung.
n To cut an ONDURA-9 sheet parallel to the corrugaons, use
a ulity knife with a sharp blade. Always cut sheets in the
valley of a corrugaon with the painted side up.
n To cut an ONDURA-9 sheet perpendicular to the
corrugaons, use a circular saw with a carbide-pped blade
or a hand saw. Apply a lubricang oil on the saw blade
to aide in a smoother cut. For best results, work with the
painted side down and mark the
cut line with a pencil on the
unpainted side.
Cut through the valley with ulity knife.
Slope = amount of rise per run
Example: 3-in rise per
12-in run = 3:12
Minimum slope required: 3:12
Run
Rise
Slope
Ridge
Eave
The rake edge of the roof should be covered to prevent water
intrusion or damage to the sheathing. The rake edge should be
covered with drip edge ashing. The drip edge ashing goes
over the felt paper on the rake edge and under the
ONDURA-9 sheet.
Drip edge ashing
on top of felt paper
on rake
Felt paper
Drip edge ashing
under felt paper
on eave
Note: At the ridge of the roof, the gap across the ridge, between
the upper ends of the ONDURA-9 sheets on each side of the
roof, will be covered by the ridge cap; and the gap should be no
more than two inches.
If your roof is wider than 36 inches, then you will need
to account for the single corrugaon overlap for adjacent
ONDURA-9 sheets. The rst ONDURA-9 sheet will provide
36 inches of coverage. Each addional ONDURA-9 sheet will
provide 32 inches of coverage with one corrugaon overlap.