Help Me Decide… Flashings
What Are They?
Flashing refers to pieces of sheet metal or other impervious material installed to prevent the passage of water into a structure from an angle or joint on the roof surface. These areas typically include the following; valley, chimney, plumbing stacks, side wall (step), front wall (apron), drip edge, and skylights.
Minimum Building Code Requirement:
- Flashings shall be installed in such a manner to prevent moisture entering the wall and roof joints at roof intersections, gutters, perimeter edges, pitch or directional changes, and around all roof openings.
- Base flashings shall be of either corrosion–resistant metal of minimum nominal 0.019inch thickness or mineral surfaced roll roofing weighing a minimum of 77 pounds per 100 square feet.
- Valley linings shall be installed in accordance with manufacturer’s instructions. Open valley linings will be of a corrosion-resistant metal of minimal nominal 0.024inch thickness or any other corrosion-resistant metal listed in table 1507.2.9.2. Closed valley lining application will have one ply of smooth roll roofing at least 36inches wide or items described above prior to installing shingle covering.
- Crickets or saddle shall be installed on the ridge side of any chimney or penetration greater than 30inches wide as measured perpendicular to the slope.
- Provide drip edge at eaves and gables of shingle roofs. Overlap to be a minimum of 2inches on gable ends and extend a minimum of 0.25inches below sheathing and extend back on the roof a minimum of 2inches.
What Flashing Options Do I Have?
Copper flashing
- 16 Oz. copper
- Custom fabricated to fit the pitch of the roof
- Joints are soldered together to create a completely watertight seal.
- Enhanced curb appeal
Heavy Gauge flashings
- .032/.040 rust resistant Kynar finish aluminum
- Custom fabricated to fit the proper pitch of the roof
- Heavier product will limit “oil canning” to give a much cleaner appearance.
- Sturdier product will not move as much as thinner products, which will reduce the risk of fracturing.
Standard gauge flashing
- .024 pre painted aluminum
- Custom Fabricated to fit the proper pitch of the roof
Minimum gauge flashings
- .019/.024 pre painted aluminum
- Preformed “out of box” to fit standard roof pitch