See Fig. 22 and 25 for Ondura installation at a slope change. Flashing width should be increased as slope differences increase or whenever water build-up on the lower slope can be substantial.

See Figures 23 and 24 on how to flash when Ondura roofing meets a sidewall.

The Ondura pipeflashing accessory is available in two sizes, can be used with hot or cold pipes, and is ideal for flashing turbine ventilators, metal chimneys, and ventilation pipes. Read the instructions on the following page and choose the correct model for your flashing needs. These instructions apply to both Ondura sheet and tile installations.

NOTE: Please also see Photos and Installation for Pipeflashing PDF under INSTALLATION GUIDELINES.

The Small Pipeflashing Accessory (12" x 12" Flat Center)

The small pipe accessory can be used for cold pipes up to 10 inches in outside diameter or for hot pipes with a maximum of 6 inches in outside diameter. To install, line up the corrugations of the accessory with those of the Ondura sheet so the pipe to be flashed will come through the center of the accessory. Cut a 15" x 15" square hole in the Ondura sheet so the accessory will nest well. Apply two beads of rubberized elastomaric caulking around the square hole before placing the accessory.

Cold Pipes -- Cut a hole in the center area of the accessory to fit the pipe. Insert the pipe. Slip en Ondura pipe flashing boot with rubber collar over the pipe, caulk the boot to the flashing accessory and then fasten it to the accessory with sheet metal screws.

Hot Pipes -- Cut a hole in the center area of the accessory that is 2 inches bigger all around than the hot pipe. Install the hot pipe manufacturer's boot with caulk and sheet metal screws. Then install the pipe manufacturer's storm collar per their instructions.

Finishing Up -- Cut a full-sized Ondura sheet to a seven-corrugation width. Cut an opening 20 inches deep from the bottom edge of the sheet and three corrugations wide. Fit the sheet over the flashing accessory so that it will cover the top and both side corrugations. This sheet should fit directly over the sheet to which the accessory is applied, be caulked to the accessory, and its upper end should be under the lap of the next higher row of Ondura sheets. Fasten with Ondura nails (see Fig. 26).

Large Pipeflashing Accessory (20" x 20" Flat Center)

The large pipeflashing accessory can be used for cold pipes up to 18 inches in outside diameter or for hot pipes with a maximum of 14 inches in outside diameter. To install, line up the corrugations of the accessory with those of the Ondura sheet so the pipe to be flashed will come through the center of the accessory. Cut a 23" x 23" square hole in the Ondura sheet so the accessory will nest well. Apply two beads of rubberized elastomaric caulking around the square hole before placing the accessory.
Cold Pipes -- Install the same as the small pipeflashing accessory.

Hot Pipes -- Install the same as the small pipeflashing accessory.

Finishing Up -- Cut a full-sized Ondura sheet to a nine-corrugation width. Cut an opening 27 inches deep from the bottom edge of the sheet and five corrugations wide. Place the sheet over the flashing accessory so that it will cover the top and both side corrugations. This sheet should fit directly over the sheet to which the accessory is applied, be caulked to the accessory, and its upper end should be under the lap of the next higher row of Ondura sheets. Fasten with Ondura nails (see Fig. 26).

The following is only a suggestion and is not intended to be a set of instructions. Each flashing situation will be slightly different. The goal is to let water run down the roof and around the chimney or skylight.

NOTE: Please also see Photos and Installation for Chimney Flashing PDF under INSTALLATION GUIDELINES.

Cut the hole from corrugation valley to corrugation valley in the Ondura sheet surrounding the chimney or skylight. Remove all the material from the hole and the material up the slope, behind the chimney or skylight. If the chimney should fall at a corrugation crown instead of a valley, the flashing must be adjusted to fit.

The down slope or front flashing should be bent down into the corrugation valley (see Fig. 27) in line with both sides of the chimney or skylight. Use Ondura closure strips and caulk between the flashing and the Ondura sheet.

Make and install the left and right side flashings (see Fig. 27). These side flashings can be bent to the corrugation shape with a pipe or a wooden dowel. Caulk side flashing in the chimney or skylight to the front flashing, and to the Ondura sheet.

Make and install the back flashing. Use rubberized elastomaric caulking to seal to all surfaces. Cut the width of the chimney or skylight from the lower end of another Ondura sheet so it will fit into place over the sheet around the chimney/skylight (see Fig. 29). Use closure strips and caulk between this sheet and the back flashing. Leave space between back of the chimney and the Ondura sheet so the water will not pond.

For valleys, install a minimum 24" wide metal valley flashing. Cut sheets or tiles at an angle to fit the valley; then turn over, and on the undersides along the valley edge, caulk two-corrugation pieces of closure strip in an overlapping pattern (Fig. 28). Then put a 1/2" bead of rubberized elastomaric caulking on the flat side of the closure strips and on the sheet between the closure strips. Turn sheets or tiles right side up, carefully lay in place so caulked closures seat on flashing, and nail in place.

CAUTION: Never rely on closures to make joints capable of resisting substantial water pressure.