Skylight Repair Guide: Fix Leaks & Save Money on Roof Maintenance - Advice from a 15-Year Roofing Contractor

My name is Michael, and I have been a licensed roofing contractor in Texas for over fifteen years. I have completed more than 2,500 roofing projects, including hundreds of skylight repairs and installations. I hold certifications from major manufacturers like VELUX and FAKRO. This article exists because I have seen too many homeowners panic when a skylight leaks. They often pay for unnecessary full replacements or get incomplete repairs that fail in the next storm. My goal is to give you the clear, honest information you need to understand your skylight problem, communicate effectively with contractors, and make a smart, cost-effective repair decision. This guide is built from my direct experience on rooftops, conversations with thousands of homeowners, and a deep understanding of building codes and manufacturer specifications. I will explain not just the 'how,' but the 'why' behind every recommendation, so you can protect your home with confidence.

The information here comes from real customer projects in the Kingwood and greater Houston area. I have reviewed manufacturer installation manuals, studied the International Residential Code (IRC) for roof openings, and tracked the long-term performance of different repair methods. My methodology is simple: I recommend solutions that are proven to last through our Texas weather, from scorching sun to torrential hail. This is not generic advice; it is field-tested wisdom from fixing skylights on homes just like yours. Let's get started and turn that worrying drip into a solved problem.

Understanding Your Skylight: Types, Parts, and Common Failure Points

Before you can fix a skylight, you need to know what you are dealing with. Skylights are not all the same. The repair approach for a fixed skylight is different from a venting one. A curb-mounted unit has different vulnerabilities than a deck-mounted model. Knowing the type and components helps you diagnose the issue accurately.

Fixed vs. Venting (Operable) Skylights

Fixed skylights are sealed shut. They are simpler and usually have fewer parts that can fail. The most common problems are sealant failures and flashing issues. Venting skylights can open to let in air. They have mechanical parts like opening arms, gears, and motors. These moving parts can wear out or break. They also have more seals that can degrade. Identifying which type you have is the first step.

Curb-Mounted vs. Deck-Mounted (Self-Flashing) Construction

This is a critical distinction for repair. A curb-mounted skylight sits on a wooden frame (the curb) built up from the roof deck. The skylight unit is then placed on this curb and the flashing is installed around it. Leaks here often occur at the flashing-to-roof connection or where the skylight meets the curb. A deck-mounted, or self-flashing, skylight has an integrated metal flange that lays directly onto the roof deck. It is then covered by shingles. Leaks here are often due to improper shingle integration or a failed seal under the flange.

Key Components and Where They Fail

Every skylight has several key parts. The glazing is the glass or plastic panel. It can crack from impact or thermal stress. The sealant is a bead of waterproof material around the glazing and frame joints. It dries out and cracks over time, especially in the Texas sun. The flashing is the metal or rubber waterproofing layer that connects the skylight to the roof. This is the #1 source of leaks I see. Step flashing (for shingle roofs) or continuous flashing must be installed correctly. The frame holds everything together. It can warp or corrode. On venting models, the operating mechanism can jam or fail.

Diagnosing Skylight Problems: Is It a Leak, Condensation, or Something Else?

Not all water near a skylight comes from a roof leak. Misdiagnosis leads to wasted money. You see a water stain on your ceiling around the skylight shaft. Your first thought is a leak. But sometimes, the problem is inside your home. Proper diagnosis saves time and targets the real issue.

True Leaks vs. Condensation: The Telltale Signs

A true leak from a failed seal or flashing will show water during or immediately after rain. The water stain often appears at the top of the skylight well or along its sides. The water path may be irregular. Condensation, however, forms on the interior surface of the glass when warm, moist indoor air hits the cold glass. This is common in winter or in humid climates. The water drips down evenly from the center of the glass. It occurs on cool, clear days without rain. Wiping the interior glass dry often solves it temporarily.

How to Perform a Simple Leak Test (Safely)

If you are comfortable and safe, you can help narrow down the leak source. Have a helper inside the attic with a flashlight during daylight. From the roof, use a garden hose to simulate rain. Start at the lowest point of the roof, away from the skylight. Slowly work the water stream up toward the skylight, soaking each area for a few minutes. The helper watches for the first sign of water inside. This can pinpoint whether the leak is at the skylight itself or higher up the roof. Never get on a wet or steep roof. If you are unsure, hire a professional. Safety is paramount.

Inspecting the Interior Shaft and Attic

Before calling a roofer, do an interior inspection. Look inside the skylight well (the finished interior tunnel). Check for stains, mold, or damp drywall. Then, if accessible, go into your attic. Use a flashlight to examine the wood framing around the skylight curb from underneath. Look for dark water stains, rot, or mold on the roof sheathing and framing members. This tells you how long the leak has been happening and how severe it is. This information is gold for your contractor.

Common Skylight Repairs: From Simple DIY to Professional Fixes

Skylight repairs range from a $10 tube of sealant to a multi-thousand-dollar full replacement. Understanding the options helps you budget and plan. I will break down the most common repairs I perform, from simplest to most complex.

Resealing the Glazing and Frame

This is the most common DIY repair attempt. Over years, the factory sealant between the glass and the metal or plastic frame dries and cracks. You can often fix this from inside your home. Carefully clean the old, cracked sealant from the joint. Use a plastic scraper to avoid scratching the glass. Wipe the area clean with rubbing alcohol. Apply a high-quality, UV-resistant sealant like Geocel 3500 or DAP Dynaflex 230. Smooth the bead with a wet finger. This is a temporary fix for minor seal failure. It does not address flashing problems.

Repairing and Replacing Flashing

Flashing repair is almost always a job for a professional roofer. It involves removing surrounding shingles, inspecting the underlying materials, and installing new flashing components. For a curb-mounted skylight, we often replace the base flashing (the part under the shingles) and the counter-flashing (the part over the curb). We use corrosion-resistant metals like aluminum or copper. The key is integrating the new flashing with the existing roof system perfectly. This repair typically costs between $300 and $800, depending on the roof pitch and materials.

Replacing Damaged Glazing (Glass or Plastic)

If the glass is cracked or the plastic dome is yellowed and brittle, you can often replace just the glazing panel. You must order the exact size and model from the manufacturer or a supplier. For a fixed skylight, this involves removing the interior trim, releasing the glazing stops, and lifting out the old panel. The new panel is set in a fresh bed of sealant. This is more affordable than a full unit replacement. Cost ranges from $200 to $600 for the panel plus labor.

Fixing Operational Mechanisms on Venting Skylights

If the skylight won't open or close, the problem is usually in the mechanism. It could be a broken manual crank, a failed electric motor, or a disconnected rod. First, check for obvious obstructions. Lubricate moving parts with a silicone spray. If that fails, you may need to replace the operating assembly. Companies like VELUX sell repair kits for their models. This repair requires working from inside, often on a ladder. It is technical but usually does not involve roof work.

The Cost of Skylight Repair: Real Project Examples and Factors

Homeowners always ask, "How much will this cost?" The answer varies widely. I will share real examples from my project log to give you a realistic expectation. Remember, prices are for the Texas market and can change.

Example 1: Simple Resealing Job. A homeowner in Atascocita had a small, fixed VELUX skylight with dried sealant. No interior damage. We cleaned and resealed the exterior perimeter and the glazing joint. Total cost: $225. This was a 30-minute repair.

Example 2: Step Flashing Replacement. A Kingwood home with a 20-year-old skylight had a leak at the head flashing (the top piece). We removed two courses of shingles, replaced the corroded flashing with new galvanized steel, and reinstalled the shingles with new nails and sealant. Cost: $475.

Example 3: Full Skylight Replacement Due to Rotted Curb. A storm-damaged skylight in Spring had been leaking for years. The wooden curb was completely rotted. We could not safely repair it. We removed the old unit and curb, built a new curb from pressure-treated lumber, installed a new deck-mounted skylight, and integrated it with the existing architectural shingles. Total cost with materials and labor: $1,850.

Factors That Influence Repair Cost

• Roof Pitch and Height: Steeper, higher roofs require more safety equipment and time. They cost more to access.
• Skylight Size and Type: A large, custom-shaped skylight costs more to repair than a standard 2x4 foot model. Venting models are more complex.
• Extent of Water Damage: If the leak has rotted the roof deck or framing, repairs must include carpentry work, which adds cost.
• Roofing Material: Repairing a skylight on a tile roof is more labor-intensive than on an asphalt shingle roof.
• Location: Skylights in the middle of a large roof plane are harder to access than those near the edge.

When to Repair vs. When to Replace Your Skylight

This is the biggest decision you will face. Repair is cheaper now, but replacement might save money long-term. As a rule of thumb, if the cost of repair is more than 60-70% of the cost of a new, comparable skylight installed, replacement is usually the better value. A new unit comes with a fresh warranty and modern energy efficiency.

Signs You Can Likely Repair

• Isolated leak at a specific seal or flashing point.
• The frame is solid, with no rot or major corrosion.
• The glazing is intact and not excessively fogged (seal failure).
• The skylight is less than 15 years old and was a quality brand.

Signs You Should Consider Full Replacement

• Multiple leak points or widespread failure.
• Rotted wooden curb or significant frame corrosion.
• Severely fogged insulated glass that cannot be repaired.
• An outdated, inefficient model where an upgrade would save on energy bills.
• Recurring repairs on the same unit—it's a money pit.

Step-by-Step Guide to Hiring a Skylight Repair Professional

Finding the right contractor is crucial. A bad repair will leak again. Follow these steps to find a qualified roofer.

1. Verify Licenses and Insurance: In Texas, roofing contractors must be licensed. Ask for their Texas Roofing Contractor License number. They must also carry general liability and workers' compensation insurance. Get proof.
2. Check for Manufacturer Certifications: A contractor certified by VELUX or FAKRO has received specific training on their products. This is a big plus.
3. Get Multiple Detailed Estimates: Get at least three written estimates. The estimate should detail the scope of work: what exactly will be repaired, the materials to be used (brand, type), and the labor warranty.
4. Ask for References and Photos: Ask for references from recent skylight repair jobs. A reputable contractor will have a portfolio of before-and-after photos.
5. Understand the Warranty: What does the workmanship warranty cover? One year is standard, but some offer longer. Get it in writing.
6. Never Pay Full Price Upfront: A reasonable deposit for materials is normal. Pay the balance only when the work is completed to your satisfaction.

Preventive Maintenance: How to Extend Your Skylight's Life

The best repair is the one you never need. Simple, biannual maintenance can add years to your skylight's life. I advise my clients to do this in the spring and fall.

• Exterior Inspection (From the Ground): Use binoculars to look at the skylight. Check for cracked sealant, loose flashing, or debris buildup around the base.
• Clean the Exterior Glass: When cleaning your windows, hose off the skylight glass to remove dirt and pollen that can trap moisture.
• Clear Debris: Ensure leaves and pine needles are not piled against the skylight curb or flashing. This keeps water flowing away.
• Interior Check: Look inside for any new condensation patterns or stains. Clean the interior glass to maximize light.
• Lubricate Moving Parts: For venting skylights, lubricate the hinges, arms, and gears with a silicone spray once a year.

Frequently Asked Questions (FAQ) About Skylight Repair

1. Can I repair a skylight leak from the inside?

Sometimes, but rarely permanently. You can seal an interior crack in the drywall or paint over a stain, but this does not fix the source. Water will find another path. True repairs almost always require exterior work on the roof to address the flashing or sealant failure where water is entering.

2. Will my homeowner's insurance cover skylight repair?

It depends on the cause of damage. Insurance typically covers sudden, accidental damage like a tree limb strike or hail damage. It does not cover wear and tear, poor installation, or lack of maintenance. Always document the damage with photos and contact your insurer. For guidance, see the Insurance Information Institute's guide.

3. How long should a skylight last before needing major repair?

A quality, professionally installed skylight should last 20-30 years. The insulated glass unit may fog after 15-20 years. Flashing and sealants need inspection every 5-10 years. Many factors affect lifespan, including installation quality, roof slope, and local climate.

4. What is the #1 mistake homeowners make with skylight leaks?

Waiting too long to address them. A small leak can cause hidden rot in the roof deck and framing. This turns a $500 flashing repair into a $3,000 structural repair. At the first sign of a stain, investigate.

5. Is it worth upgrading to a new, energy-efficient skylight?

Often, yes. Modern skylights have Low-E coatings and argon gas fills that drastically reduce heat gain in summer and heat loss in winter. If your skylight is old, single-pane, or constantly causing temperature issues, an upgrade can improve comfort and lower energy bills. Look for units with an ENERGY STAR rating.

6. How do I know if the fog between my skylight panes is a problem?

Fog or condensation between the sealed glass panes means the insulated glass unit (IGU) seal has failed. This reduces insulation value but does not usually cause a water leak into your home. The repair involves replacing the entire IGU, not the whole skylight. It is a common repair for units over 15 years old.

Real Project Case Study: A Kingwood Home Saved from Major Damage

Last year, I was called to a home in Kingwood. The homeowners saw a small water spot on their ceiling after a heavy rain. They thought it was a one-time thing. When I inspected the attic, I found extensive, hidden rot in the roof sheathing around the skylight curb. The leak had been slow for years. The repair quote was high because we needed to replace a 4x8 foot section of roof deck. However, because we caught it before the rot spread to the structural rafters, we saved them from a truly catastrophic repair. We replaced the rotted wood, installed a new ice and water shield underlayment, replaced the skylight with a modern, energy-efficient unit, and matched the existing shingles perfectly. The total project cost was $3,200. The alternative—ignoring it for another year—could have led to interior ceiling collapse and mold remediation costing over $15,000. This case shows the value of prompt, professional inspection.

Conclusion: Your Action Plan for Skylight Health

Skylights bring beautiful light into your home, but they require attention. Do not fear them; understand them. Start with a simple interior and attic inspection. If you see signs of a leak, act quickly. Get multiple estimates from licensed, insured, and certified professionals. Ask detailed questions about their diagnosis and repair plan. Invest in quality repairs or replacements that will last. Finally, commit to simple biannual maintenance. This proactive approach will protect your home, your wallet, and your peace of mind. You now have the knowledge to be an informed homeowner. If you are in the Kingwood area and have questions, feel free to reach out to local professionals who value education as much as service. Your home is your biggest investment; protect it wisely.