A leaking skylight on a metal roof is usually a sign that water is getting in through failed seals, flashing issues, or movement in the roofing system.

If you notice water stains on your ceiling, dripping during rain, or damp patches around the skylight, the problem needs attention before it leads to serious roof damage.

Skylights on metal roofs are especially prone to leaks because metal expands and contracts with temperature changes, which can slowly break down sealants and create gaps over time.

The good news is that most skylight leaks can be identified and fixed properly once you understand where the issue is coming from.

This guide explains the common causes, how to diagnose the leak, and the correct way to repair it so it doesn’t come back.

Most Common Causes of Skylight Leaks

Skylights are a great way to bring natural light into your home, but they also create a penetration point in your roof. On metal roofing systems, several common issues can lead to leaks.

Here are a few of the most common issues:

1. Worn or Damaged Rubber Seals

Most skylights rely on rubber gaskets between the glass and frame. Over time, these seals can dry out, shrink, or crack, allowing water to seep in during rainfall.

2. Faulty or Loose Flashing

Flashing is designed to direct water away from the skylight. If it becomes loose, corroded, or poorly sealed, water can pool and eventually enter the roof cavity.

3. Thermal Expansion and Movement

Metal roofs naturally expand in heat and contract in cold conditions. If the skylight sealing system cannot handle this movement, small gaps can form and cause leaks over time.

4. Poor Installation

Incorrect flashing alignment, insufficient sealant, or poor installation practices can create long-term leak problems—even if materials are high quality.

How to Find Where the Leak Is Coming From

Before repairing a skylight leak, it’s important to pinpoint exactly where the water is entering. Water can travel along roof sheets before dripping inside, making the entry point misleading.

Check the following areas:

• Skylight seals: Look for cracks, gaps, or hardened rubber
• Flashing edges: Check for rust, lifting, or missing sealant
• Roof surface around skylight: Look for pooling water or debris buildup
• Interior signs: Identify the exact point of staining or dripping

Simple leak test:

If rain isn’t present, gently hose the roof in sections around the skylight. Have someone observe inside to identify when and where the leak appears.

How to Fix a Skylight Leak on a Metal Roof

Once the source is identified, repairs can be carried out. The key is ensuring a clean, flexible, and weather-resistant seal that can handle roof movement.

1. Reseal or Replace Skylight Seals

• Remove all old or cracked sealant completely
• Clean the surface thoroughly before applying new material
• Use a high-quality, UV-resistant exterior sealant
• Ensure a continuous, gap-free seal around all edges

Proper sealing is critical to prevent future leaks caused by minor movement in the roof.

2. Repair or Replace Flashing

• Clean all flashing surfaces to remove dirt and corrosion
• Remove failing sealant or damaged sections
• Install a flexible waterproof membrane if needed
• Ensure proper adhesion to both skylight and metal roof

Flashing is one of the most important barriers against water entry, so it must be installed and sealed correctly.

3. Test the Repair

After completing repairs:

• Check all seal edges for gaps or thin areas
• Ensure water flows away from the skylight, not toward it
• Test using a hose or wait for rain to confirm no leakage

A proper test ensures the repair is successful and long-lasting.

Preventing Future Skylight Leaks

Regular maintenance is the best way to prevent skylight leaks from returning.

Recommended maintenance tips:

• Inspect skylights at least once a year
• Check seals before winter and after summer
• Keep roof areas around skylights clear of debris
• Address small cracks or seal failures immediately
• Ensure gutters are clean to avoid water overflow issues

Preventative maintenance reduces the risk of major roof damage and expensive repairs.

DIY vs Professional Skylight Repair

Some minor sealing issues can be managed with DIY repairs, but skylights on metal roofs often involve complex water movement and structural expansion.

DIY may be suitable for:

• Small seal cracks
• Surface-level re-sealing
• Minor cosmetic repairs

Professional help is recommended for:

• Flashing damage or lifting
• Persistent or hidden leaks
• Roof access safety concerns
• Multi-point or recurring leaks

Incorrect repairs can trap moisture and make the problem worse over time.

Maintenance Tips for Longevity

Even a tightly sealed patch still needs maintenance to continue functioning. Here are some easy tips:

• Inspect annually: Look at all of your skylights for cracks, and at a minimum, inspect the seals and flashings at least twice a year, a month before summer and a month before winter. Temperature shifts can create enough movement to allow the waterproofing to be compromised.
• Clean regularly: Chunks of debris, leaves, and dirty stains can accumulate in areas of the skylight that can create moisture next to the skylight. A surface that is regularly maintained and easy to clean will allow water to drain properly and wear evenly.
• Address minor problems immediately: If you see small cracks, seams, or crumbling sealant, don’t let it go; it will inevitably get worse and end up being larger leaks.

Why Choose Sun SoftWash?

Selecting the right company to do the repair work is as important as the repair itself. With Sun SoftWas, you get experience, quality service, and peace of mind:

• Specialized roof knowledge: They know the ins and outs of metal roofs and skylights, and everyone in the industry knows they do it the right way and without cutting corners.
• Safe and cost-effective service: Sun SoftWash provides a safe and affordable service, as we believe results should never have to be sacrificed.
• Attention to detail: Every repair is handled as an individual. Their team will make the solution stick and not just be a Band-Aid.
• Tailored solutions: Quotes are free and so is the advice – it’s how we start, so that YOU know what you need done before anything starts.

With Sun SoftWash, your skylight repair is handled by professionals who prioritize lasting results, safety, and customer satisfaction.

Final Words

A leaking skylight on a metal roof is a common issue, but it should never be ignored. Most leaks are caused by failing seals, flashing issues, or natural roof movement—and all can be properly repaired when handled correctly.

With the right diagnosis, proper materials, and careful installation, you can restore a watertight seal and protect your home from further damage.

If maintained regularly and inspected seasonally, your skylight can remain a durable and valuable source of natural light for many years.