A leaking skylight requires immediate attention to prevent water damage, mold growth, and structural issues in your home. The first step is always to contain the water using a bucket or towel to minimize interior damage while you assess the situation ^[5][8]. For minor leaks, DIY solutions like applying silicone-based sealants or checking flashing may provide a temporary fix, but most sources emphasize that professional inspection is often necessary—especially for skylights over 10 years old or with persistent leaks ^[2][5][9]. The root causes typically include damaged flashing, worn weatherstripping, cracked glass, or improper installation, all of which require different approaches ^[1][4][7].

Key immediate actions to take:

• Place a bucket under the leak and move furniture/valuables away from the water path ^[5][8]
• Dry the affected area with fans or heaters to prevent mold ^[9]
• Inspect the skylight’s flashing, seals, and surrounding roof area for visible damage ^[1][6]
• Determine whether the leak occurs only during rain (external leak) or also in dry weather (condensation issue) ^[10]

Addressing and Repairing Skylight Leaks

Immediate DIY Fixes for Minor Leaks

For small, recent leaks, homeowners can attempt temporary repairs while waiting for professional help or to buy time before a full replacement. The most effective short-term solutions involve sealing cracks and reinforcing flashing. A silicone-based sealant like Super Silicone Seal (recommended in multiple sources) adheres to glass, metal, and plexiglass, providing a durable patch when applied correctly ^[3][1]. The Family Handyman suggests waterproof tape as another quick fix for minor damage, though this is not a permanent solution ^[7].

Steps for a DIY sealant repair:

• Remove old caulking: Scrape away deteriorated sealant using a putty knife or wire brush, ensuring the surface is clean and dry ^[3][6].
• Clean the area: Use rubbing alcohol or a degreaser to remove dirt, oil, or moisture, which can prevent adhesion ^[3][1].
• Apply masking tape: Place tape around the edges of the repair area to create clean lines and protect surrounding materials ^[3].
• Sand the surface: Lightly sanding the glass or metal with 120-grit sandpaper improves sealant adhesion ^[3].
• Apply sealant and fleece: Use a high-quality silicone sealant (e.g., Super Silicone Seal) combined with fleece fabric for reinforcement. Press the fleece into the wet sealant for a stronger bond ^[3].
• Allow proper curing time: Follow the product’s instructions—most sealants require 24–48 hours to fully cure ^[1].

Limitations of DIY repairs:

• Sealants are temporary fixes and may last only 1–3 years, especially in extreme weather ^[1].
• If the skylight frame is warped or the glass is cracked, sealing alone won’t resolve the issue ^[4].
• Flashing problems (metal strips around the skylight) often require professional re-installation, as improper handling can worsen leaks ^[2][7].

When to Call a Professional Roofer

Most sources strongly recommend professional intervention for skylight leaks, particularly in these scenarios:

• The skylight is 10+ years old, as seals and materials degrade over time ^[2][9].
• The leak persists after DIY sealing attempts, indicating a deeper issue like faulty installation or structural damage ^[5][10].
• The skylight is deck-mounted (installed flush with the roof), which is more complex to repair than curb-mounted units ^[9].
• There’s visible mold, rotting wood, or ceiling stains, suggesting long-term water intrusion ^[1][7].

What professionals will assess:

• Flashing integrity: Flashing (the metal barrier around the skylight) is the most common leak source. Professionals check for rust, gaps, or improper sealing ^[4][6].
• Skylight age and condition: If the unit is near the end of its 10–20 year lifespan, replacement is often more cost-effective than repeated repairs ^[9][2].
• Roof compatibility: Poor installation (e.g., incorrect slope or sealing) can void warranties and require a full re-installation ^[10].
• Ventilation and condensation: Professionals can identify if leaks stem from clogged weep holes (drainage paths) or excessive indoor humidity ^[1][10].

Cost considerations:

• Minor repairs (resealing, flashing adjustments): $350–$600 ^[7].
• Full skylight replacement: $1,000–$3,000+, depending on size and type ^[5].
• Roof damage repairs: If leaks have affected decking or insulation, costs can escalate significantly ^[9].

Professional repairs typically include:

• Re-flashing the skylight with aluminum or copper for durability ^[2].
• Replacing weatherstripping and gaskets around movable (vented) skylights ^[4].
• Ensuring proper slope (skylights should be installed at a 5–15 degree angle to prevent water pooling) ^[10].
• Checking attic ventilation to reduce condensation-related leaks ^[1].

Preventive Measures to Avoid Future Leaks

Regular maintenance can extend a skylight’s lifespan and prevent leaks. The most critical tasks involve inspections, cleaning, and humidity control ^[1][6][10].

Essential maintenance steps:

• Inspect skylights biannually: Check for cracks, sealant deterioration, and flashing gaps in spring and fall ^[6][7].
• Clear debris: Remove leaves, branches, and dirt from the skylight and surrounding roof area to prevent water pooling ^[1][10].
• Clean weep holes: These small drainage holes at the skylight’s base can clog with insects or dirt, causing leaks. Use a wire or compressed air to clear them ^[1].
• Monitor indoor humidity: Condensation on skylights can mimic leaks. Use dehumidifiers or ventilation fans to keep indoor humidity below 50% ^[1][8].
• Trim overhanging branches: Tree limbs can damage skylights during storms and drop debris that traps moisture ^[7].

Long-term prevention tips:

• Upgrade to double-pane or low-E glass to reduce condensation and improve insulation ^[1].
• Install a skylight cover (e.g., acrylic dome) to protect against hail and UV damage ^[10].
• Ensure proper attic ventilation to prevent heat and moisture buildup that can warp skylight frames ^[1].
• Re-seal skylights every 3–5 years as a proactive measure, even if no leaks are visible ^[6].