Velux skylight flashing is critical for creating a weather-tight seal around a skylight. This guide delivers clear, step-by-step instructions and best practices for installing Velux skylight flashing, addressing common models, tools, and tips to prevent leaks. It covers preparation, material choices, and proper sealing to help both DIYers and professionals achieve durable results.
What Your Velux Skylight Flashing Includes
Velux flashing kits are designed to integrate with specific skylight sizes and roof types. Typical components include the top flashing, side flashing, bottom flashing, a step flashing system for shingle roofs, underlayment, sealants, and fasteners. Understanding what comes in the flashing kit ensures a correct fit and prevents water intrusion. Always verify model compatibility with the skylight and roof pitch before starting installation.
Safety And Preparation
Safety is paramount when working on roofs. Use a sturdy ladder, harness if necessary, and weather-appropriate gear. Inspect the roof for damaged shingles or existing flashing that could complicate installation. Prepare the work area by clearing debris and laying down a drop cloth. Have all tools ready before removing the skylight’s existing flashing to minimize exposure. If the roof is steep, consider hiring a professional for safety and compliance reasons.
Tools And Materials You’ll Need
- Velux flashing kit compatible with the skylight model
- Measuring tape and marker
- Utility knife and scissors
- Caulking gun and high-quality sealant compatible with roofing materials
- Roofing nails or screws as required by the kit
- Roof sealant or flashing adhesive
- Putty knife and roof cement for edge sealing
- Chalk line or straightedge for alignment
- Safety equipment: gloves, eye protection, and fall protection if needed
Understanding Roof Type And Model Compatibility
Velux flashing varies by roof material (shingle, metal, tile) and skylight size. The flashing must match the skylight model and the roof pitch. Misalignment can cause leaks or wind-driven water intrusion. Refer to Velux installation manuals for model-specific diagrams and required underlayment. If the roof has unusual features, such as curb-mounted skylights or vented units, check for any additional flashing accessories required by Velux.
Step-By-Step Installation Process
The following steps outline a typical Velux skylight flashing installation for a shingle roof. Adjustments may be needed for metal or tile roofs; consult the kit instructions for roof-specific steps.
- Prepare The Opening: Remove interior coverings and clean the skylight opening. Verify dimensions align with the flashing kit. Ensure the roof surface around the opening is dry and free from debris.
- Install The Underlayment: For most Velux kits, an underlayment or peel-and-stick membrane is applied to shed water away from the opening. Align it with the roof slope and trim excess material to fit under the top flashing.
- Fit The Top Flashing: Position the top flashing against the roof deck, ensuring it sits flush with the shingles and has proper overlaps. If using self-adhesive flashing, remove the release film gradually to avoid trapping air.
- Attach Side Flashings: Install the side flashings along each side of the skylight, sliding them under or over shingles according to the kit instructions. Use corrosion-resistant fasteners as specified by Velux.
- Apply The Bottom Flashing: Attach the bottom flashing, ensuring a smooth seal along the lower edge. This piece often overlaps the underlayment and side flashings to create a continuous seal.
- Seal Joints And Corners: Apply a continuous bead of sealant along joints, critical corners, and any seam intersections. Allow the sealant to cure per manufacturer guidelines before exposing to weather.
- Install Step Flashing For Shingle Roofs: If applicable, install step flashing where the skylight meets the shingles. Interlace the step flashing with shingles to direct water away from the opening.
- Check Alignment And Seals: Verify the skylight is level and the flashing sits properly against the roof plane. Re-check all seals, edges, and fasteners for tightness and even contact with the roof surface.
- Finish Interior Sealing: Inside the mounting flange, apply interior sealant to close any minor gaps and to enhance interior moisture control, following Velux guidelines.
Common Installation Pitfalls And How To Avoid Them
- Using Incompatible Flashing: Always confirm model compatibility. Incompatible kits can fail to seal properly, leading to leaks.
- Poor Siding And Overhang: Inadequate overhang can direct water toward the skylight. Ensure proper lateral sealing and sufficient shingle coverage over the flashing.
- Inadequate Sealant Curing Time: Do not expose fresh sealant to rain or foot traffic until it cures as recommended by Velux.
- Skylight Misalignment: Small misalignments can compromise the seal. Use level and measurement tools to verify alignment during installation.
- Neglecting Roof Penetrations: If there are roof penetrations nearby (vents, chimneys), plan flashing to avoid interference and ensure proper flashing overlaps.
Maintenance And Longevity
Velux skylight flashing is designed for durability, but regular checks help prevent leaks. Inspect flashing for cracks, lifting edges, or damaged sealant after severe weather or at least twice a year. Clear any debris from around the skylight. Replace damaged flashing components promptly using Velux-approved parts to maintain warranty coverage. Clean the skylight glass and seals to keep a clear view and proper seal integrity.
Weather Considerations And Seasonal Timing
Install flashing during dry weather with moderate temperatures to maximize sealant performance. Avoid installation in freezing conditions or during heavy rain. If summer heat affects sealant curing, allow for extended curing times per product guidelines. In regions with rapid weather changes, plan installations to minimize exposure of open seams to precipitation.
Frequently Asked Questions
- Do I need underlayment with Velux flashing? Yes, most kits require underlayment or membrane to direct moisture and seal edges properly.
- Can I install Velux flashing myself? For capable DIYers with roofing experience, it is feasible. Always follow the manufacturer’s instructions and safety guidelines.
- How do I know which flashing kit to buy? Check the skylight model number, roof type, and pitch. Velux provides a compatibility chart with most kits.
- What if I notice a leak after installation? Inspect seals, reapply sealant if necessary, and verify flashing overlaps and fasteners. If leaks persist, contact Velux support or a roofing professional.
Additional Resources
For installers seeking precise diagrams and model-specific steps, consult Velux official installation manuals and product sheets. Local building codes may require permits or specific flashing practices, so confirm compliance before starting. High-quality Velux replacement parts are recommended to maintain system performance and warranty coverage.