Lead and Flashing

Common Flashing Materials:

• Metal Flashing: Lead, aluminum, copper, stainless steel, and zinc alloys are the most common metals used. Each has unique benefits, such as copper's longevity and malleability and aluminum's resistance to corrosion.

• Rubberized and Flexible Flashing: Materials like rubberized asphalt, butyl rubber, and polyvinylidene fluoride offer flexible, adhesive-backed solutions for easier installation, especially in non-standard roof penetrations or complex configurations.

Types of Flashing:

1. Roof Flashing: Used around chimneys, vents, and roof valleys to prevent water from entering at discontinuities.

2. Wall Flashing: Directs water away from wall intersections, often at window and door openings, to prevent water infiltration.

3. Sill Flashing: Placed under windows and door thresholds to prevent water entry at these points.

4. Step Flashing (Soaker Flashing): Installed at roof-to-wall intersections, overlapping in "steps" to shed water away from vulnerable areas.

5. Pipe Flashing (Boots/Flanges): Specifically designed to seal around pipes or vent penetrations on the roof, preventing water from entering at these openings.

Installation Considerations:

• Proper Overlap: Flashing pieces should overlap to ensure a continuous barrier against water infiltration.

• Materials Compatibility: Care should be taken not to use incompatible metals that could cause galvanic corrosion, such as copper in contact with aluminum.

• Movement Allowance: Expansion joints should be included in long runs of metal flashing to accommodate thermal expansion and contraction.

• Seam Integrity: Flashing should be properly sealed, particularly in joints, to prevent leaks, especially in high-stress areas like valleys or at penetration points.

Special Flashing Types:

• Kickout Flashing: Installed at the junction of a roof and wall to direct water away from the building.

• Drip Edge Flashing: Installed at the roof edges to prevent water from running under the shingles or tiles.

• Chimney Flashing: Used around chimneys to prevent water infiltration where the chimney meets the roof.

Flashing must be engineered and installed correctly to ensure that water is directed away from a structure, preventing water damage. Improper flashing installation can lead to leaks and the opposite effect, allowing water to penetrate the building envelope.

Do you have a specific application or project in mind where you're considering flashing? We'd be happy to provide further guidance! So contact us below.