Drive shingle nails through the valleys 4 1/2" from the top edge of the tile so that the lapping tile covers heads. Drive perpendicular into roof decking - not at an angle - so nail head is snugly in contact with tile. See Fig. 14. Don't overdrive or underdrive nails. You can also use a roofing nail gun: however, never use a staple gun.

Use only genuine 3" Ondura nails to drive through corrugation crowns at the eave, through ridge cap at corrugation crowns, and at the lower corners and center of end lap of each tile to protect against wind lift. See Fig. 16.

All roofing requires ventilation. It's a false economy to try to conserve heat in an uninsulated building by closing off ventilation openings. That's because poor ventilation can cause severe condensation problems and dripping, which in turn can cause deterioration of roof framing and covering materials.
See Fig. 36* for suggestions on how to take advantage of Ondura's corrugated design and Ridgeline Ridge Vents and Ondura Ventilated Closure Strips to assist ventilation.

*This may not be sufficient ventilation for all buildings, especially animal confinement structures. Check with an engineer.

1. From the corner where the eave and rake meet, measure along the eave 48 inches and mark.

2. From the corner of the rake and the ridge, measure along the ridge 48 inches, plus or minus the out-of-square distance determined earlier, and mark.

3. Snap a chalk line between these marks for tile alignment.

4. Now you can install the first tile with a 1" overhang. Starting at the rake edge of the tile, nail down the first corrugation so that this edge is aligned with the rake.

5. Now flex the tile (1" or less) so its opposite edge aligns with the chalk line. (See Figure 15 or 18.) With a shingle nail, nail in the first valley from this edge. Place a closure strip between the tile and drip-edge and nail tile in place with shingle nails (4 1/2" from top) and Ondura nails (through closure at eave). See Fig. 16 and 21. Check eave alignment to insure installation is straight.

NOTE: The flexibility of Ondura sheets and tiles may lead to misalignment or "spreading" if care is not taken to keep sheet and tiles at nominal width (48") during installation.

1. From the corner where the eave and rake meet, measure along the eave 48 inches and mark.

2. From the corner of the rake and the ridge, measure along the ridge 48 inches and mark.

3. Snap a chalk line between these marks for tile alignment.

4. Now you can install the first tile with a 1" overhang. Starting at the rake edge of the tile, nail down the first corrugation so that this edge is aligned with the rake.

5. Place a closure strip between the tile and drip-edge and nail tile in place with barbed roofing nails (4 1/2" from top of tile) and Ondura nails (through closure at eave). See Fig. 16 nailing pattern. Check eave alignment to insure installation is straight.

NOTE: The flexibility of Ondura sheets and tiles may lead to misalignment or "spreading" if care is not taken to keep sheet and tiles at nominal width (48") during installation.

1. From the first chalk line, mark off successive 44-inch spaces along the eave. Do the same at the ridge. This distance allows for a 1-corrugation side lap.

2. Snap chalk lines between the eave and ridge marks for tile alignment.

3. Now lap the second tile one corrugation over the first, fastening it as you did the first one (See Fig. 19).

4. Continue fastening tiles until you are five tiles from the end of the Cave row. Lay the last five into position to see if you have a tile valley flush with the rake. (See Fig. 20.) If you do not have a valley flush with the rake, shift all five unnailed tiles left or right until you have a valley flush with the rake. Fasten these tiles in place with closure strips beneath eave edge.

1. Snap a chalk line (or pull a string line) 14" from the lower edge of the first row of tiles (See Fig. 17).

2. Begin the second and all even-numbered rows with a tile cut along a valley with a knife so that this tile has only six crowns. (See Fig. 21.) Doing this staggers side-laps from row to row so there are never four tiles thick at any point.

3. Place this six-corrugation tile flush with the rake edge, butting the chalk line snapped on the first row. This will give you an even exposure along the roof.

4. Nail this tile in place and install the remainder of the second row using full tiles.

5. Continue installing rows on both sides of roof until reaching the ridge. (See Fig. 21.)

NOTE: With roof valley, always flash the valley first, then work from the rake edge to the valley.