Skylight Leaks in Rain - Causes and Solutions

Skylights are a great way to bring natural light into your home. But when it rains, skylights can sometimes leak and cause water damage.

Getting to the root of the problem is the first step toward preventing future skylight leaks during rainstorms. With some DIY troubleshooting, maintenance, and repairs, you can stop pesky skylight leaks for good.

Causes of Skylight Leaks in the Rain

There are several potential causes of skylight leaks when it rains:

• Improper installation - If the skylight or flashing was not installed correctly, gaps can allow water intrusion.
• Sealant or gasket issues - Cracked, deteriorated, or missing sealant around the skylight can lead to leaks.
• Faulty flashing - Corroded, poorly fitted, or improperly installed flashing is a common culprit.
• Condensation buildup - Trapped moisture between the skylight and roof can leak in.
• Loose fasteners - Skylight frame fasteners can vibrate loose over time.
• Debris buildup - Leaves, dirt and debris can prevent proper drainage.

Pinpointing the exact cause of the leak is an important first step. A professional roof inspection can help identify issues like deterioration or faulty installation. Condensation buildup may indicate a ventilation issue. And a simple cleaning may solve debris-clogged drainage problems.

Improper Installation

Skylights require meticulous installation and flashing to prevent water seepage. The skylight frame must integrate seamlessly with the roofing material. Any gaps, cracks, or imperfect seals can allow rainwater to leak through. Poorly installed or fitted flashing is another common culprit.

Skylights should only be installed by trained professionals. An improperly installed skylight will likely leak over time as seals deteriorate and flashing loosens or corrodes. Replacement and reinstallation are the best fixes for a leaky skylight caused by improper installation.

Sealant and Gasket Issues

The sealant and gaskets around the edges of the skylight play a critical role in preventing water intrusion. Over time, this sealant can crack, dry out, or go missing entirely. Deteriorated or missing sealant provides an easy entry point for rainwater.

Inspect the sealant carefully for any gaps, cracks, drying, or missing sections. Reapplying a high-quality sealant around the skylight frame and flashing can seal small leaks. For more significant sealant issues, full resealing and potential skylight replacement may be needed.

Faulty Flashing

Flashing is used to divert rainwater away from vulnerable spots like joints and seams. When skylight flashing is incorrectly installed, corroded, or fitted poorly, leaks can result. Faulty flashing is one of the most common causes of rain-related skylight leaks.

Inspect flashing for corrosion, looseness, cracking, or improper installation that could allow water seepage. Flashing may need to be resealed, reinforced, or replaced entirely depending on the extent of damage. A roofing professional can ensure proper skylight flashing installation.

Short Term Fixes for Skylight Leaks

For a quick fix to stop a skylight leak until permanent repairs can be made, try these short-term solutions:

• Remove any debris buildup on the skylight and surrounding roof area.
• Apply sealant or caulk around the skylight frame and flashing.
• Use plastic sheeting or temporary sealant/caulk directly on the leak.
• Check and tighten any loose fasteners on the skylight frame.
• Improve insulation and ventilation around the skylight to reduce interior condensation.
• Install temporary drainage paths to divert water away from the skylight.

While short-term fixes like caulk and plastic sheeting can temporarily stop leaks, permanent repair solutions will be needed to prevent recurring issues. Use quick fixes as an emergency response, not a permanent solution.

Sealants and Caulk

In a pinch, exterior-grade caulk or sealant can patch small leaks at the skylight frame, flashings, or glass. Carefully apply the sealant directly to the source of the leak. This offers a temporary waterproof barrier.

Silicone or polyurethane sealant tends to work best for skylights. But even properly applied sealant is only good for 6-12 months before replacement is needed. It buys time for planning more lasting repairs.

Plastic Sheeting

For an immediate leak stopper, plastic sheeting or tarps can be secured over the skylight with tape or temporarily fastened with battens or lumber strips. This shields the skylight from rain while more robust repairs are arranged.

Sheeting is quick and handy for emergency leak situations. But it tends to be unstable long-term. It can tear, degrade, and blow off in wind. Focus on diagnosing and permanently fixing the root cause of the leak rather than relying on sheeting indefinitely.

Permanent Solutions for Leaky Skylights

To stop skylight leaks for good, permanent solutions are required. Here are some of the most effective permanent skylight leak repairs:

• Reseal the skylight and reinstall or replace flashing.
• Replace the entire skylight unit with proper installation.
• Add supplemental drainage elements under the skylight.
• Apply protective sealant coatings to the skylight glazing.
• Extend roof eaves over the skylight to divert rainwater.
• Hire a professional skylight installer for comprehensive repairs.

Permanent skylight leak repairs often require scaffolding or a roofer's ladder to safely access the skylight. Homeowners should take care not to risk injury if the skylight is too high or slippery to reach.

Resealing and Flashing Replacement

Resealing the skylight frame with fresh high-quality sealant can permanently patch small leaks. Severe sealant deterioration may require replacing the old sealant completely after cleaning and surface prep. Flashing should also be checked and replaced if faulty.

A roofing contractor can ensure proper sealant selection and application. The skylight frame and flashing interface will be sealed weather-tight to prevent future water intrusion.

New Skylight Installation

If the current skylight is too old, damaged, or incorrectly installed to repair reliably, replacement is the best option. Installing a brand new skylight with professional flashing ensures optimal performance.

A good quality skylight built with durable materials and weather-tight seals can provide leak-free operation for over 20 years. Proper installation is key to maximizing skylight lifespan.

Add Drainage Elements

Extra drainage provisions underneath the skylight can divert water safely away before it can leak inside. Drainage elements like kick-out flashing, crickets, and drip edges give water an escape route.

Built-in gutters with downspouts or low-profile drainage channels can also improve skylight drainage on flat or low-slope roofs. Careful slope consideration and drainage provisions make leaks less likely.

Preventing Future Skylight Leaks

With some regular maintenance and preventative care, costly skylight leak repairs can often be avoided:

• Clean and inspect skylights routinely for damage, debris, or deterioration.
• Keep all sealants, gaskets, and flashings in good condition.
• Ensure proper slope, drainage provisions, and support under the skylight.
• Install skylight shades to protect from UV and weathering.
• Select durable, high-quality skylight materials resistant to leaks.

Catching minor issues early, keeping everything in working order, and preventing weathering are the best ways to avoid major skylight repairs down the road.

Regular Inspections & Maintenance

Make skylight inspections part of routine roof maintenance. Clean off any debris around the skylight to prevent clogs. Check for missing, cracked, or deteriorated sealant and reseal as needed. Tighten any loose screws or connections.

Wash skylight glass occasionally with mild soap and water to remove grime and enhance light transmission. Well-maintained skylights typically achieve 20+ years of useful life.

Proper Installation

Investing in professional installation of quality skylight units prevents many leakage issues down the road. Ensure roofing contractors properly waterproof and integrate the skylight with step flashing, sealants, and roofing materials.

Proper skylight slope, drainage, and integration during construction or re-roofing also helps avoid leaks. Do not cut corners on initial skylight installation.

Skylight leaks during rainstorms or heavy weather can lead to annoying and damaging water intrusion. But armed with an understanding of what causes skylight leaks along with DIY maintenance tips and professional repair solutions, homeowners can tackle leaks decisively.

Focus on regular inspection and preventative care along with quality initial installation. Your skylights can provide beautiful natural lighting for decades before major repairs are needed. With some diligence, you can stop those frustrating skylight leaks for good.