Introduction
Kickout flashing is a metal or plastic piece that redirects roof water away from a wall at a roof-to-wall transition. It helps keep water from getting behind siding and causing damage.
To install it, fit the kickout snugly against the wall framing and under the roofing edge, then fasten according to the material you’re using. Make sure water sheds away from the wall and into the gutter or flashing system. Check the product label, manufacturer instructions, and local rules for any requirements.
Key takeaways
- Kickout flashing directs runoff from roof to siding to prevent leaks.
- Verify compatibility with roofing, siding, and local codes before install.
- Use proper sealant and flashing lap details per manufacturer instructions.
- Prepare the wall edge and fascia to accept kickout without gaps.
- Secure all components, keep work area clear, and wear PPE during installation.
- Inspect from ground and ladder line for proper integration and water shedding.
Table of Contents
- Introduction
- Key takeaways
- What Is Kickout Flashing and Why It Matters
- Building Codes, Standards, and When It Is Required
- Types, Materials, and Material Specs Explained
- Tools and Materials Checklist
- Pre-Installation Preparation and Visual Checkpoints
- Step-by-Step Installation — Standard Asphalt Shingle Roof to Vertical Siding
- Installation Variations: Masonry, Metal Roofs, and Complex Rooflines
- Common Mistakes, Troubleshooting, and Inspection Checklist
- Conclusion
- FAQ
What Is Kickout Flashing and Why It Matters
Kickout flashing is a metal boot that directs roof runoff away from the wall where the roof meets siding. Its shape and placement are designed to bridge the gap between the roof edge and the vertical surface. The basic function is to prevent water from traveling behind siding and under roofing materials.
When kickout flashing is missing or installed incorrectly, water can intrude at the wall line, leading to rot, mold, and eventual exterior damage. The consequences can show up gradually, but they all trace back to misdirected runoff and failed water control. Always verify the manufacturer’s instructions for how your kit should be installed.
Definition and function
Kickout flashing is a crucial component at roof-to-wall transitions. It’s an L-shaped metal strip that diverts water from the roof edge, preventing it from running down the wall.
Unlike step or counterflashings which protect joints between different building materials, kickouts direct water away from walls to protect them from moisture damage.
Key point: Kickout flashing isn’t just about aesthetics; it’s a vital part of your home’s defense against water intrusion.
Failure modes and risks
Missing or improperly installed kickout flashing can lead to serious issues. Water running down walls can seep into gaps, causing rot, mold, and mildew.
You might not notice these problems immediately. They often hide behind siding or within wall cavities, growing worse over time. By the time you see signs, repairs can be costly and extensive.
Tip: Regularly inspect your roof-to-wall transitions for any signs of water damage to catch potential issues early.
Building Codes, Standards, and When It Is Required
Most jurisdictions and manufacturers expect kickout flashing at roof terminations where the roof meets a vertical wall or siding. Check the local code book or the authority having jurisdiction for specifics in your area. The goal is to ensure the flashing is integrated with both the roofing and wall assemblies as intended.
Inspectors commonly look for flashing at roof terminations against vertical walls, and many codes reference installation in accordance with manufacturer instructions. If you’re unsure, compare the installation with the product data sheet and your local rules before proceeding. Always document the code references you rely on for future inspections.
Relevant codes and best practices
To ensure your kickout flashing meets standards, consult these documents:
Local Building Code: Check for specific requirements in your area. Most codes mandate flashing at roof-to-wall intersections.
Roofing Manufacturer Instructions: Follow their guidelines for proper installation and placement of kickout flashing.
WRB (Water-Resistive Barrier) Guidelines: Ensure the WRB extends up the wall and is properly flashed to prevent water intrusion.
Typical locations inspectors check
Inspectors commonly look for kickout flashing at these critical points:
Exterior Wall Junctions: Where the roof meets exterior walls, especially at corners and intersections.
Eaves: At the overhanging edge of the roof where it meets the wall below.
Dormers and Other Roof-Wall Intersections: Inspectors will check for proper flashing where dormers or other roof features meet vertical walls.
Types, Materials, and Material Specs Explained
Common kickout flashing materials include aluminum, galvanized steel, copper, and PVC-coated options. Each has its own balance of durability, corrosion resistance, and ease of work in different climates. Consider how it will respond to sun exposure and heat cycles on your roof edge.
When selecting material, verify properties that affect compatibility with your roof and cladding, such as thickness, coating, and corrosion resistance. Ask about how it bonds with sealants and with the WRB system you’re using. If in doubt, check the label, product data sheet, or manufacturer guidance for your climate and materials.
Profiles and Prefab vs Field-Formed
Kickout flashings come in two main types: prefabricated and field-formed.
Prefab: These are factory-made, shaped to specific profiles. They’re easy to install, fit well, but may not suit complex roof lines perfectly.
Field-Formed: Metal sheets bent on-site. They offer a custom fit but require more skill and time for installation.
Compatibility and Corrosion Concerns
When different metals meet, galvanic corrosion can occur. This happens when one metal acts as an anode, sacrificing itself to protect the other.
Prevent it: Use compatible materials or add protective barriers like tape or paint between them.
For instance, don’t mix aluminum and copper directly. Always use a barrier or ensure they’re not in direct contact.
Tools and Materials Checklist
Assemble a practical kit: a snips or shears suitable for the flashing material, a hammer or crimping tool, sealant compatible with roofing and siding, and fasteners of the correct type for the substrate. Don’t forget lath or a backing under the edge if your wall requires it.
Include safety gear such as gloves, eye protection, and a stable ladder or scaffolding. Before starting, verify inventory and ensure all parts match the roofing and siding materials you’re tying together. If you’re unsure about fastener type, consult the product instructions or manufacturer recommendations.
Essential tools
Before you start, check off this list to ensure you have everything needed for a smooth installation.
- Snips: For cutting metal. Get both straight and tinsnips for different cuts.
- Seamer: To bend and shape metal flashings as needed.
- Hammer: For tapping down fasteners and shaping metal.
- Caulk gun: To apply sealants and adhesives.
- Fasteners: Nails, screws, or other fasteners that match your siding and roofing materials.
- Tape measure: To ensure accurate cuts and placement.
- Level: For checking the horizontal alignment of your flashing.
- Chalk line: To mark out cutting lines on metal.
Quick rule: Having the right tools saves time and prevents mistakes. Don’t skip this step.
Materials and sealants
Use this checklist to gather all necessary materials before starting your kickout flashing installation.
- Kickout flashing: Pre-formed or field-formed, matching your roofing and siding materials.
- Underlayment: Ice and water shield or felt paper, depending on your roof type.
- Fasteners: Nails, screws, or other fasteners that match your chosen flashing material.
- Sealant/Adhesive: Appropriate for your flashing material (e.g., butyl tape for metal).
- Roofing cement: For securing the top of the flashing to the roof.
- Siding material: Matching siding pieces or trim for finishing the kickout.
- Drip edge: To prevent water from getting behind the flashing at the bottom.
- J-channel or corner trim: For finishing the sides of the kickout.
Quick rule: Using compatible materials and sealants prevents leaks and ensures longevity.
Pre-Installation Preparation and Visual Checkpoints
Start with a thorough visual check of the roof deck, shingles, WRB, and siding terminations. Look for loose or damaged shingles and compromised WRB spots that could impact flashing performance. Address any obvious rot or soft spots before installing the kickout.
Ensure the substrate is flat and dry, with any uneven areas corrected. Confirm WRB continuity at the wall edge and ensure the siding is properly backed to receive the flashing. If anything looks suspect, repair or replace before you proceed.
Assessing the intersection and substrate
Before installing new flashing, use this checklist to inspect the roof-to-wall intersection. This will help you identify any issues that could lead to costly rework or water damage.
- Check for rot at the intersection: Look for soft, crumbly wood or discoloration. Use a screwdriver to poke the area; if it’s soft, there’s rot. What goes wrong if you skip this: Water will continue to seep in, causing further damage and potentially leading to structural issues.
- Inspect sheathing condition: Check for missing, damaged, or loose sheathing. Tap it with a hammer; if it sounds hollow or feels weak, replace it. What goes wrong if you skip this: Inadequate sheathing can’t support flashing properly and may lead to leaks.
- Measure slope of the roof: Use a level to ensure the roof slopes away from the wall at least 1/8″ per foot. What goes wrong if you skip this: Improper slope can cause water to pool and leak into your home.
- Check for proper flashing overlap: Ensure existing flashing overlaps the roofing material by at least 2 inches. What goes wrong if you skip this: Inadequate overlap allows water to get behind the flashing and cause leaks.
- Inspect drip edge: Make sure there’s a drip edge along the roof’s lower edge to direct water away from the building. What goes wrong if you skip this: Without a drip edge, water can run down the sides of your home and cause damage.
- Check for proper ventilation: Ensure there are no obstructions in the roof’s overhang that could trap heat and moisture. What goes wrong if you skip this: Improper ventilation can lead to ice dams, mold growth, and structural damage.
- Look for signs of animal intrusion: Check for nests, droppings, or other signs that animals may have entered the roof. What goes wrong if you skip this: Animals can cause damage to your roof and bring pests into your home.
- Verify attic insulation: Ensure there’s adequate insulation in the attic to prevent ice dams and keep your home energy-efficient. What goes wrong if you skip this: Insufficient insulation can lead to heat loss, increased energy bills, and potential water damage.
Quick rule: Always address any issues found during the inspection before installing new flashing. This will help ensure a durable, long-lasting repair.
WRB, Underlayment, and Siding Tie-In
Use this checklist before installing siding to ensure proper integration with the weather-resistant barrier (WRB) and underlayment. This will help maintain a continuous water shedding plane.
- Check WRB laps: Ensure all WRB layers overlap by at least 4 inches. Check for any tears or punctures.
- Inspect underlayment: Make sure the underlayment is flat, secure, and free of wrinkles. Check that it extends beyond the WRB by at least 2 inches.
- Verify siding starter course: Ensure the siding’s starter course is installed correctly, covering the bottom edge of the WRB and underlayment.
- Check siding laps:<