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If you want a solar system and you have a metal roof, clap your hands! The installation is fast and simple and your PV modules will get some extra sunlight. In this article, we’ll take a quick look at how to install solar panels on a metal roof.
Key takeaways
- Metal roofing is great for solar panels because this material is strong and lasts a long time. This means you probably won't need to take the panels off to fix the roof later.
- Putting solar panels on a metal roof can be quick and easy, especially on roofs with raised seams. Sometimes, you don't even need to drill holes in the roof.
- Metal roofs can even help your home solar panels work better by reflecting more sunlight onto them. This can make your system produce more power.
- While usually good, putting solar panels on a metal roof can have some downsides. Metal roofs can cost more than other types, and certain metals might rust over time, especially near the ocean.
- How you put solar panels depends on the type of metal roof you have. Roofs with raised seams are easier because you can often attach panels without drilling. Wavy metal roofs need special parts and careful screwing to avoid leaks.
DIY installation: Disclaimer
Homeowners usually don't install solar panels by themselves. In the US, you often need permission from the government to put solar panels on your roof. Officials allow only certified professionals to perform the installation. This guide is purely informative to let you better understand the process of attaching solar panels to a metal roof.
Installing solar panels by yourself can be fine with small projects: an RV, a boat system, or a DIY experiment in your garage. If you're confident in your skills — go for it. Remember though that you might not be eligible for programs from the government and utilities if it’s not the professionals who install panels. DIY installation may void the warranties for your solar panels.
Benefits & drawbacks of metal roofs
Contractors consider metal roofs among the best for solar panel installations. The benefits of this type include:
1. Durability. A metal roof is a stable and secure platform with a lifespan of over 50 years. This aligns well with the long lifespan of solar panels.
2. Reflectivity. Sunlight bounces off metal onto the solar panels from various angles which increases their efficiency. With a metal roof, you can even consider bifacial solar panels for a residential installation. The active rear side of a bifacial PV module provides up to a 25% production bonus to the front side.
3. Easy installation. With the right approach, mounting solar panels on metal roof. Some types of metal roofs don’t even require penetration.
No matter the type, metal roofs are much easier to work with than, say, tile roofs. The installation of a solar system of up to 15 kilowatts can be done in a day.
What about the drawbacks? If you consider replacing your roof before installing solar, a metal roof is more expensive than alternatives. Depending on the type of metal used and its coating, there can be a risk of corrosion over time, especially in coastal environments.
Metal roofs are very durable and long-lasting, with lifespans that exceed the 25-30 year warranty of most solar panels. This means you likely won't need to remove and reinstall the panels due to roof replacement, saving you time and money. They are also strong and can easily support the weight of solar panels.
Installation on many metal roof types, especially standing seam roofs, can be easier and less invasive. Special clamps can attach directly to the seams without requiring drilling into the roof, which helps prevent leaks and maintain the roof's warranty.
Furthermore, metal roofs, particularly lighter colors, are highly reflective, which can help keep your building cooler and potentially improve the efficiency of the solar panels by reducing their operating temperature.
However, there can be some potential downsides. For certain types of corrugated metal roofs, drilling might be necessary for bracket installation, which requires careful sealing to prevent leaks.
Also, if you have a galvanized steel roof, there's a risk of corrosion where rainwater runs off aluminum solar panel frames onto the galvanized metal. It's crucial to use compatible materials and ensure proper installation by experienced professionals to avoid these issues.
Procedure varies: Metal roof types
The process of installing solar panels on a metal roof changes depending on what type you have. The most common types are standing seam roofs and corrugated ones.
Standing seam metal roofs need no drilling
Metal roofs with standing seams are the most convenient for installing solar panels. You can attach the modules directly to the seams. Not only is it super simple, but it also allows the air to circulate under the panels. It contributes to the cooling of the system, raising the efficiency of solar panels.
Leave 4-6 inches between panels and the roof for proper air circulation
Metal roof jobs are fast on standing seam roofs. You can use S5 clamps and there’ll be no penetrations. Versa brackets have better wind load ratings but penetrate your roof and may void the warranty.
Corrugated roofs require more care
The task of installing solar panels on a corrugated metal roof needs a different approach. The profile itself is not strong enough to support the mounting system so you’ll have to attach the brackets with the help of the screws.
There is a variety of brackets for corrugated roofs on the market. Most are designed to fit on the ridges though some are to be fixed in the valleys. The mounting may vary depending on whether you have a trapezoid or a sinusoidal metal roof.
Whenever you perform the drilling, waterproofing is especially important. Use a sealant to cover the holes and prevent leaks. Remember that drilling may cause problems with the roof warranty and it’s better to check with your provider beforehand.
So, companies make things like brackets or short metal pieces called mini-rails. These parts are designed to sit right on top of the raised parts of your corrugated metal roof. To hold them down, you usually use screws that can drill right into the metal. These screws often come with a soft, squishy washer that seals the hole and stops water from getting in.
Once these brackets or mini-rails are attached firmly to the roof's ridges, they become the base for holding the actual solar panels. The solar panels then get clamped or bolted onto these bases. This way, the panels are held securely, close to the roof, and there aren't big gaps that wind could catch. Using the right parts and putting them in the right spot on the ridges helps keep your roof strong and leak-free while you make clean energy.
Safety concerns
Aside from special brackets, mounting solar panels on a metal roof largely follows the general PV system installation process. The system has to be grounded to prevent damage from lightning or power surges.
U.S. Climate Bill: 30% Solar Tax Credit comes backA pitched metal roof requires installers to have proper fall protection. When there are no standing seams, an anchor is attached to the roof directly. Installers should make sure that this anchor won’t create leaks once it is removed.
Andrey had been a news editor and freelance writer for a number of medias before joining A1 SolarStore team. Climate change and its impact on people's lives has always been among his interests and it partially explains his degree in Philosophy and Ethics.
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