Adding skylights on roof surfaces can transform any space by increasing natural light and improving energy efficiency. However, when it comes to metal roofs, replacing a skylight isn’t as straightforward as with asphalt or shingle roofs. The unique properties of metal roofing—its expansion, contraction, and specific sealing needs—mean that a poorly executed skylight installation can lead to costly water damage and structural issues.
If your skylight is leaking, cracked, or no longer functioning properly, replacing it requires careful planning. This guide will walk you through everything you need to know about skylights repair, choosing the right materials, and maintaining your skylight for long-term durability.
Signs You Need a Skylight Replacement
Skylights have a lifespan of about 10-20 years, depending on materials and exposure to weather conditions. Here are some warning signs that indicate it’s time for a skylights repair or replacement:
1. Persistent Leaks and Water Damage
One of the most common skylight issues is water leakage, which can result in stains on your ceiling, mold growth, and even structural damage to your roof. If you notice leaks around your skylights on roof, the flashing or sealant may be deteriorating. Metal roofs require specialized flashing to accommodate movement due to temperature changes.
2. Cloudy, Discolored, or Cracked Glass
A foggy skylight means that the seal between the glass panels has failed, allowing moisture to enter. Cracked or discolored skylights also reduce energy efficiency and can increase heating and cooling costs (Natural Resources Canada).
3. Difficulty Regulating Indoor Temperature
If your home is hotter in summer and colder in winter despite insulation, your skylight could be the problem. A failing skylight loses its ability to regulate heat transfer, making skylight installation with modern, energy-efficient glazing a smart investment.
4. Worn or Loose Fasteners
Metal roofs expand and contract with temperature shifts, which can loosen screws and weaken the attachment points of skylights. If you notice fasteners pulling away, it may be time to replace the skylight and reinforce its attachment.
Choosing the Right Skylights on Roof for a Metal Roof
Replacing a skylight on a metal roof requires more than just swapping out the old one. Selecting the right type and ensuring a secure skylight installation is key to preventing leaks and premature failure.
1. Fixed vs. Vented Skylights on Roof – Which One is Better?
- Fixed Skylights – Best for metal roofs as they have a lower risk of leaks. These skylights are sealed permanently and do not open for ventilation.
- Vented Skylights – Ideal for moisture-prone areas like kitchens and bathrooms, but require high-quality flashing and a professional skylight installation to prevent leaks.
2. Material Choices for Skylights on Roof: Glass vs. Acrylic Skylights
- Tempered Glass – Provides excellent insulation and is more durable than acrylic. Modern skylights feature Low-E coatings to reduce UV exposure and heat gain.
- Acrylic Skylights – More affordable and lightweight but prone to scratches and discoloration over time.
Choosing the right skylight type depends on factors like energy efficiency, durability, and roof compatibility. If you’re unsure which skylight is best for your home, check out this guide on the best skylights on roof for every home for expert recommendations.
3. Proper Flashing and Sealant for Skylights on Roof
Using incorrect flashing is one of the leading causes of skylights on roof leaks. Metal roofs require specialized self-adhering flashing or standing-seam flashing to accommodate movement. Silicone-based sealants are recommended over asphalt-based sealants for better adhesion on metal surfaces.
How to Replace Skylights on Roof of a Metal Building
Skylight replacement involves precise installation steps to ensure longevity and leak prevention.
Step 1: Assess the Existing Skylight and Roof
- Check for rust, corrosion, or weak areas around the skylight opening.
- Measure the dimensions to ensure compatibility with the new skylight installation.
Step 2: Remove the Old Skylight
- Unscrew and carefully lift the existing skylight.
- Scrape off old sealant and clean the surface thoroughly.
Step 3: Prepare the Opening for Installation
- Apply a waterproof underlayment around the skylight opening.
- Install new flashing to fit securely with the metal roof profile.
Step 4: Secure the New Skylight
- Position the new skylights on roof and fasten it with corrosion-resistant screws.
- Apply high-quality sealant around the edges.
Step 5: Perform a Leak Test
- Spray water around the skylight and check for leaks.
- Inspect the interior for moisture buildup.
Common Skylight Problems & How to Prevent Them
Skylights on roof structures add natural light and a stylish touch to any home, but if they’re not installed or maintained properly, they can cause more harm than good. Here’s a look at common skylight issues and how to prevent them:
1. Leaks from Poor Sealing
Leaks are one of the biggest complaints with skylights on roof installations. If the sealant around the skylight isn’t applied correctly, water can seep in and cause serious roof damage. To avoid this, always use high-quality, flexible sealants designed for metal roofs. Proper flashing and professional installation will also help keep water out and your skylight leak-free.
2. Condensation and Mold Growth
Without proper insulation, skylights on roof surfaces can trap moisture, leading to condensation and mold. Over time, this can weaken the skylight and the surrounding roof. The best solution is installing a skylight with double glazing, which helps regulate temperature and reduce moisture buildup. Good attic ventilation also plays a key role in keeping condensation under control.
3. Roof Expansion Can Damage Skylights
Metal roofs naturally expand and contract with temperature changes, which can put stress on skylights on roof structures. If they aren’t installed with the right materials, cracks can form over time, leading to leaks or the need for skylights repair. To prevent this, make sure expansion-friendly fasteners and flexible flashing are used during skylight installation.
4. Regular Maintenance is Key
Even a well-installed skylight needs upkeep to stay in good shape. The maintenance of skylights should include checking for worn-out seals, clearing debris, and inspecting the surrounding roofing material for signs of damage. Taking care of these small tasks regularly can help avoid expensive repairs down the road.
With proper installation and routine maintenance, skylights on roof designs can brighten up your home without causing unnecessary problems. A little attention now can save you from major headaches later!
Skylight Maintenance Tips to Extend Lifespan
Regular maintenance of skylights helps prevent costly repairs. Follow these essential tips:
- Inspect Annually – Look for cracks, leaks, and worn seals.
- Clean Skylight Glass – Use a mild detergent and soft cloth to remove dirt and debris.
- Check Fasteners and Flashing – Tighten loose screws and replace deteriorated flashing.
- Reseal if Necessary – Apply a fresh layer of sealant every few years to maintain waterproofing.
Should You Hire a Professional for Skylight Replacement?
While DIY skylight installation may seem like a cost-saving option, mistakes can lead to expensive repairs. Here’s a quick comparison:
Factor | DIY Installation | Professional Installation |
Cost | Lower upfront | Higher but includes expertise |
Risk of Leaks | High | Low, with proper sealing |
Durability | Uncertain | Longer lifespan & warranty |
Time Required | Several days | Completed within hours |
Professionals ensure correct skylight installation, reducing the risk of water damage and maximizing energy efficiency.

Conclusion
Replacing skylights on roof surfaces requires careful planning to prevent leaks and maintain the integrity of a metal roof. By choosing the right skylight, ensuring proper skylight installation, and following regular maintenance of skylights, homeowners can enjoy the benefits of natural light without worry.
If you need help with skylights repair or a new skylight installation, consult a professional roofing contractor to get the best results. Contact a trusted expert today for a free estimate!