FAQ

Quick Tips for Installation
Installing The Second Row Of Sheets.
The second row can be installed so that all
side-laps meet lower sheets in the middle, or so that
all side-laps line up from row to row up the slope of
the roof to offset the side lap of one row from the
other.
To stagger the side laps from row to row,
begin the second row with a sheet cut in half along
its length (see Fig. 4). Be certain to cut the sheet in
its valley. Since the edge of this first sheet will not
line up with the chalk line of the first row, make a
new line half a sheet’s distance from the rake. Now
install the remainder of the second row using full
sheets and new chalk lines every 44 inches (112cm)
for alignment. Lap the lower end of the second row
7 inches (17,8 cm) over the upper end of the first
row. Be certain that the center of each lap is over the
center of the purlin beneath.
To have all side laps of all rows line up,
simply begin the second row with a full sheet and
install this and all subsequent rows in the same man-
ner as in the first row (see Fig. 5).
Fig. 4
Fig. 5
Installing Ridge Caps.
Install all sheets on both sides of roof before
laying the ridge. At the ridge the upper end of the
sheets should be no more than 2 inches (5,08cm)
apart to properly support the ridge cap.
Place the first ridge cap at the end of the
ridge away from the prevailing wind, allowing it to
project out 3 to 6 inches (7,62 to15,24cm) from the
ridge end. Insert closure strip then drive ONDURA
nails through ridge piece, closure strip and every
Crown (Not Valley) of the underlying sheets. Now
cut in 3 to 6” inches (7,62 to 15,24cm) along the
crown of the portion of ridge cap projecting out from
the end. Fold down the resulting flaps for a weather
guard. Position the subsequent ridge caps with a 7
inch (17,8cm) end lap.
Information for Quick Estimating.
ONDURA Sheets are 79” x 48” (200cm x 122cm)
ONDURA Ridge Caps are 79” x 19” (200cm x
48cm)
Sheets needed to cover 100 square feet = 4.5
End lap each ridge cap by 7” (17,8cm)
Use 24 nails per sheet
Use 38 nails per ridge cap
Closure strips needed:
Total the length in inches of the eaves plus twice the
length of the hips, ridges, and valleys. Divide the
total inches by the 44 (the length of the closure
strips) to get the number of closures needed.
For more installation information consult the
complete Ondura Installation Guide or visit our web
page at www.ondura.com.
Onduline North America
4900 Ondura Drive
Fredericksburg, VA 22407 – USA
Tel: [phone], Fax: [phone]
www.ondura.com
Fig. 6 Ridge Cap at Gable End
Fold down flaps on end of Ridge Cap.