Sidewall Flashing

Purpose of Flashing: Flashing prevents water from penetrating into the building structure by directing water away from vulnerable areas, such as windows, doors, and joints. Critical Areas to Flash: The most critical areas to flash are around windows, doors, roof intersections, and any other penetrations through the exterior wall (e.g., vents, decks). Window Flashing Process: Install sill flashing with a downward slope. Apply flashing tape to the sides (jamb flashing). Install head flashing over the window and tape. Ensure all flashing layers overlap properly to direct water outward. Common Materials for Flashing: Aluminum, copper, and galvanized steel are common. PVC and rubberized asphalt are also used for their flexibility and adhesion properties. Copper is highly durable and recommended for longevity. Roof vs. Window Flashing: Roof flashing often involves more rigid materials and needs to handle greater water flow, requiring careful integration with shingles and gutters. Window flashing generally focuses on sealing around the frame. Consequences of Inadequate Flashing: Improper flashing can lead to water intrusion, which causes mold, rot, and structural damage. Capillary Action and Prevention: Capillary action refers to the movement of water within small spaces due to surface tension. Properly overlapped and sealed flashing prevents this by blocking pathways for water to enter. Integration with Weather-Resistant Barriers: Flashing should overlap with weather-resistant barriers by at least 6 inches, or according to manufacturer’s specifications, to ensure a continuous moisture barrier. Recommended Overlap for Flashing Materials: Flashing materials should overlap at least 2 to 4 inches, depending on the type of material and the specific area of application. Sealing Flashing Around Doors and Windows: Use a high-quality sealant compatible with both the flashing material and the substrate. Seal all edges and joints thoroughly. Code Requirements: These can vary by region, but generally, flashing must be corrosion-resistant, must be installed so water is directed outwards and away from the structure, and must cover all potential water entry points. Influence of Siding Material: Different siding materials may require different flashing techniques, particularly in terms of thermal expansion and contraction, as well as how the siding overlaps with the flashing. Chimney Flashing Considerations: Flashing around chimneys must include both step flashing along the sides of the chimney and counter flashing that embeds into the masonry to ensure water flows away from the chimney. Importance of Kick-out Flashing: Kick-out flashing is essential at the lower roof edge where it meets a vertical sidewall; it directs water into the gutter, preventing it from running down the wall. Testing Flashing Effectiveness: Use a water test after installation to check for leaks. This can be done by flowing water on the exterior while checking the interior for any water infiltration. Signs of Failing Flashing: Look for peeling paint, signs of mold or mildew, water stains on interior walls or ceilings, and any visible corrosion or damage to flashing material. Climate Factors in Flashing Selection: In colder climates, consider materials that resist contraction and expansion. In areas with heavy rainfall, prioritize robust water management features. Common Mistakes in Installation: Overlooking proper overlaps, improper sealing, and using incompatible materials are common mistakes that compromise the effectiveness of flashing. Construction of End Dams: End dams should be constructed at the ends of the flashing runs to prevent water from leaking around the edges. They should be made of durable, non-corrodible material. Ongoing Maintenance: Homeowners should regularly inspect flashing for damage, clear debris from areas near flashed sites, and ensure sealants and joints remain intact.