Adding a skylight or sun tunnel is a popular way to brighten Oregon homes naturally, but avoiding leaks is critical due to the region’s frequent rain. Whether you’re a homeowner planning a DIY project or a contractor tackling a client’s roof, careful installation is essential to keep interiors dry and protected.
Choosing the Right Option: Skylight vs. Sun Tunnel
Before planning the installation, consider the benefits and limitations of each option:
- Skylights create a direct window to the sky, offering expansive views and abundant daylight. They are best for rooms with access to the roof structure and ceiling space.
- Sun tunnels (also called tubular skylights) funnel sunlight through a reflective tube, making them ideal for smaller rooms, hallways, or interior spaces where a traditional skylight won’t fit or would be cost-prohibitive.
In Oregon, both options must be able to withstand heavy rain and wind, so product selection and installation methods matter as much as the design.
Common Causes of Leaks
Leaks around skylights or sun tunnels are almost always the result of improper installation or aging roof components. These are the most frequent culprits:
- Flashing errors: Incorrect or missing flashing is the most common cause. Flashing must be integrated with roofing material, not just lapped over it.
- Poor sealing: Relying only on caulk or sealant, instead of proper step flashing and underlayment, leads to eventual failure.
- Incompatible products: Some roofing materials require specific skylight flashing kits. Using generic or mismatched kits can create gaps.
- Improper placement: Installing too close to valleys, eaves, or roof transitions increases leak risk.
Key Steps for Leak-Free Installation
Whether you’re installing yourself or hiring a contractor, these steps help ensure a watertight result:
- Start with the right curb or flashing kit. Use manufacturer-supplied flashing kits designed for your roof type (asphalt shingle, metal, tile, etc.).
- Inspect and prepare the roof deck. Repair any rot, delamination, or mold before cutting your opening. Damaged decking cannot hold fasteners securely and may allow water intrusion.
- Integrate flashing with underlayment. Run self-adhering waterproof underlayment (such as ice and water shield) up the sides of the opening and onto the roof, lapping it in the correct direction for water runoff. Step flashing should be woven into the shingles, not merely tacked on top.
- Install counter-flashing and sealants as specified. Use high-quality sealant only where specified, such as at fastener heads or certain joints. Overuse of caulk is a common mistake and can trap water rather than shed it.
- Check for proper slope and positioning. Install skylights and sun tunnels on a slope (not flat) unless the unit is specifically rated for flat installations. Position away from roof valleys or areas where snow and debris accumulate.
- Finish with weatherproofing details. For sun tunnels, ensure the dome and flashing are set above the finished roofline to prevent pooling. Use the supplied storm collar and sealant on exposed fasteners.
Oregon-Specific Installation Considerations
Oregon’s wet climate places extra demands on roof penetrations. Here are practical adjustments and tips for local conditions:
- Choose high-flange or curb-mounted skylights. These shed water more effectively than low-profile models, especially on low-slope roofs common in the region.
- Inspect roof age and condition. Installing on an old or failing roof can lead to future leaks, even if the skylight is installed perfectly.
- Pay close attention to flashing underlayment at the top edge. Oregon storms often bring wind-driven rain; extra attention to the head flashing and underlayment prevents backflow leaks.
DIY or Hire a Contractor?
Many handy homeowners can tackle sun tunnel installations or basic curb-mounted skylights on shingle roofs. However, consider hiring a professional if:
- The roof pitch is steep or the roof is high off the ground.
- The roof uses specialty materials (metal, tile, etc.) that require specialized flashing and tools.
- You need to reroute framing, wiring, or plumbing vent lines.
- There are existing signs of leaks or moisture damage.
A qualified contractor brings experience in integrating roof penetrations with various roof types and can often offer longer leak-free guarantees.
Inspection and Maintenance Tips
Even a perfectly installed skylight or sun tunnel needs periodic checks. Here’s a practical schedule:
- Inspect annually, especially after heavy rain or windstorms. Look for water stains, peeling paint, or bubbling drywall near the opening.
- From the roof, check for cracked or missing shingles, lifted flashing, or debris buildup. Clean off leaves, moss, and dirt that can trap moisture.
- Check sealant beads and fastener heads. Reapply only if you see visible cracking or separation. Don’t rely on caulk alone to stop leaks.
Next Steps: Leak-Free Skylight Success Checklist
- Choose the right skylight or sun tunnel product for your roof material and slope.
- Use complete manufacturer flashing kits and follow instructions precisely.
- Inspect the roof deck and underlayment for moisture or rot before cutting.
- Integrate underlayment and flashing with the roofing system—don’t shortcut steps.
- Inspect and maintain yearly to catch minor issues before they become leaks.
- If unsure, especially with complex roofs, contact a local installer experienced in Oregon’s climate.
With careful planning and attention to proven installation details, you can enjoy natural daylight in your home—without the headache of leaks.