Installation Guide for Tower™ Roofing

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7. Metal Drip Edge and Metal Flashings

All metal flashings should be a minimum 26 gauge (0.4 mm) galvanized steel, pre-painted galvanized steel, or 16 oz copper. It is recommended that valleys be a minimum of 24” (60 cm) wide. Fasteners should not be placed within 6” (15 cm) of the lowest point of the valley. To ensure no nails within 6" (15 cm) of the lowest point of the valley, when coming into the valley, stop at the second last shingle and cut the valley piece first and then cut the shingle next to it to fit the space remaining to complete the course. Alternatively, if the appearance of the roof is affected with the aforementioned procedure, when a piece of shingle is required that is less than 6" (15 cm) wide such that a nail would be closer than 6" (15 cm) to the lowest point of the valley, those small shingle pieces may be set in place with a urethane adhesive or a silicone adhesive. These small pieces are not part of the water shedding of the roof and are in place for aesthetics only. Ice and Water is to be installed before putting the metal valley into place (refer to detail 001).

Detail 001: Valley Detail

Drip edge must be installed on the bottom edge of the roof (eaves) and on open gable ends. The ‘lip’ of the drip edge must extend 1/2” (1.25 cm) past the edge of the roof (refer to detail 002).

Detail 002: Drip Edge Detail

The drip edge must be installed over the edge of the ice and water protector, and then a minimum of a 6” (15 cm) strip of the ice and water is to be placed over the drip edge from the edge of the roof to 3” (7.5 cm) past the edge of the drip edge in the field of the roof (refer to detail 002). The installation of metal flashing is required in valleys, along side walls of dormers, around chimneys and any protruding structure that may hold a snow load or allow water to penetrate. The metal flashing is to be over top of the ice and water protector installed in those locations.

If there is a change in roof slope, ice and water protector should be used along this juncture (extending 18” (45 cm) on each slope) and the shingles should be brought up to that slope change as if it were a ridge. Metal flashing should be installed in such a way that the bottom of the flashing allows water to flow over the field shingles of the lower roof.

The upper roof should then be treated as an eave. A strip of ice and water should be installed under the drip edge and extending 18” (45 cm) up the slope of the roof. A minimum 6”(15 cm) strip of ice and water protector should be installed over the edge of the drip edge extending up the slope to ensure that ice and water covers the fasteners in place as well as extending 3” (7.5 cm) past the horizontal edge of the drip edge. Install TowerTM Shake or TowerTM Slate from the change in slope of the roof as if you were starting at the eave again (without the need to overhang the eave 1/2” (1.25 cm) ) with starter shingles and field shingles. (refer to detail 004).

Important Reminder:
DO NOT copper flashings with aluminum eaves trough. Sulfites from the copper will corrode the aluminum.

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