It's important to emphasize that while a roofer may have experience with installing roofs, they may not necessarily have the specialized training and experience required to properly install skylights. Here are a few reasons why it's important to hire a professional skylight contractor rather than just a roofer for skylight replacements:

1. Expertise in skylight installation: Professional skylight contractors have extensive training and experience specifically in installing skylights. They are familiar with the unique challenges and considerations that come with installing skylights, such as proper ventilation and sealing to prevent leaks. A roofer may not have the same level of expertise in these areas.
2. Proper equipment and safety measures: Installing skylights can be a complex and potentially dangerous task, especially if you have a steep or sloped roof. Professional skylight contractors have the necessary safety equipment and training to ensure that the installation is done safely and efficiently. A roofer may not have the same level of safety training or equipment.
3. Warranty coverage: Most skylight manufacturers, including Velux, require that skylights be installed by a professional contractor in order to be eligible for the manufacturer's warranty. If you hire a roofer to install your skylights, you may void the manufacturer's warranty and be left without coverage if something goes wrong with your skylights.

Overall, while a roofer may have experience with installing roofs, they may not have the specialized training and experience required to properly install skylights. Hiring a professional skylight contractor ensures that the installation is done correctly and safely, and also preserves any manufacturer's warranties.