Metal roofs are durable, low maintenance, and capable of withstanding the worst of the elements. So it's no wonder that installing solar on metal roofs is an increasingly popular topic among homeowners. Ease of installation, durability, and environmental benefits are just three of the reasons to consider putting solar panels on a metal roof.
The most common roofing material in the United States is asphalt shingles, and for good reason: they're inexpensive, durable, and come in a wide variety of styles and colors. But while they're less popular, metal roofs have a lot of advantages. If you're a homeowner with a metal roof, you might wonder: can solar panels be installed on a corrugated metal roof?
In short, yes, you can install solar panels on a metal roof. Worry not - thanks to bracketing systems, solar panels can be installed on most types of metal roofing.
In this article, we cover the basic ways the base mounting brackets are attached to different types of metal roofs, answer some common questions related to metal roofs and solar panels.
Metal roofs and solar panels pair well together
Metal roofs are great for solar, because they last a very long time. If it's time to replace your roof before you can go solar, you may consider investing in a metal roof install as well.
Metal roofs can last up to 70 years, whereas asphalt composite shingles are expected to last just 15-20 years. Most solar panel installations are guaranteed to last 25 years, but systems will be producing at strong capacity well beyond that.
When it becomes time to invest in new panels, say 30-35 years from now, you can simply swap the panels out without having to mount brackets and rails. This can potentially save you a lot of time and expense much further down the road if you're planning on staying in your home a long time.
Types of Metal Roof
Many residential properties, modern constructions, and businesses favor metal roofs, which means they are often non-standard in shape, with no uniform design.
There is a reliable installation method and bracketing system for every metal roof type.
Standing Seam Metal Roof
This roof type consists of a series of flat, broad metal panels that are crimped together to form a continuous, concealed join. There is a vertical leg between each one; this is the raised seam.
Not only is this type of roof lightweight and durable, when installed in sequence with the recommended underlayment, it is also watertight.
It's almost as if metal standing seam roofs are specifically designed with solar panels in mind.
The installer attaches a series of high-strength aluminum clamps to the vertical legs with a single bolt. The mounting rail secures into place with no need to drill any holes into the roof. With no perforations in the metal, it remains watertight – people with asphalt shingles have to check and maintain theirs annually.
Installing a solar array on a seamed roof is simpler and far-less labor-intensive, and therefore, more affordable.
The clamps and bolts are often covered by several-year warranties, although most owners claim they outlive their solar panels.
Another solar panel installation method that doesn't require drilling any holes or penetrating the metal. A similar system is also available for regular asphalt tiled roofs.
The mounting rail has metal tiles pre-attached. It is a simple case of aligning them with existing tiles and swapping them out. The unit clicks into place, and the panels are easily attached using guiding metal rods.
The tiles are consistent in shape to the existing ones, so they don't create an eyesore or leave any unwanted gaps for moisture to creep in.
They offer natural protection for the roof, preserving its condition.
Corrugated Metal Roof
There is no way of installing solar panels onto a corrugated metal roof without drilling holes; every care is taken to ensure they remain watertight.
It requires a specialized mounting system that uses brackets called straddle blocks. They attach securely to the top ridge, leaving the lower crest, where the rain collects, free from holes. Top-quality brackets have thick rubber gasket seals to plug the holes; they are more effective and less messy than using sealant gum.
Straddle blocks work with any uneven metal roof and where there are varying degrees or gaps between panels.
The blocks align with the installation grommets on the rear of solar panels to ensure secure placement.
Solar metal roofs can host thin-film panels in addition to standard PV panels
The majority of homeowners with solar in the United States are installing standard silicon photovoltaic (PV) solar panels, but homes with metal roofs have another option – thin film solar. Thin film solar can only be installed on certain types of roofs, and standing seam metal roofs are an ideal surface.
While PV panels offer higher efficiency per square foot, thin film solar panels have a lower profile and are easier to install. They also require much less energy to manufacture than silicon solar cells, which can make them a lower-emissions renewable energy option from the start.
Can Metal Roofs Handle the Weight of Solar Panels
In general, yes, metal roofs can handle the weight of solar panels. However, each roof is different and will need to be evaluated before solar panels are installed.
A third-party structural engineer will visit your building to inspect the structure of your roof to make sure it can stand up to the additional weight of your solar panels. In most cases, the roof can handle the added weight, and the engineer will sign off on the project.
Additional support will be needed to safely install the system for the few roofs that don't pass inspection. The engineer will make the required recommendations for reinforcing the roof and the structure. If you'd still like to move forward with the project, the alterations can commence. Then, the engineer will revisit the site and sign off on the project.
Will Solar Panels Damage a Metal Roof
While they last several decades, metal roofs are a substantial investment. You don't want to do anything to cut the life of your roof short. Even if doing so will bring you decades of free electricity, like with solar panels.
However, as long as your solar panels are installed on par with industry standards, you won't be causing any short- or long-term damage to your roof. In fact, solar panels can actually protect your roof.
While they're not indestructible, solar panels are designed and installed to withstand a pretty good beating from mother nature. They'll act as a buffer, shielding your roof from the typical wear and tear over time.
When it comes to securing your solar panels to your metal roof, you can rest assured you won't be exposing your building to any leaks. Solar panels installed on standing seam roofs can typically be installed with no penetrations. Ribbed metal roofs will require penetrations. However, the bolting system is specifically designed to prevent leaks for the lifespan of your solar panel system.
How to find a company to install solar panels for your metal roof
If homes with metal roofs are common in your area, you may be able to easily find local companies that have experience installing solar on metal. However, you should always get multiple quotes from installers to ensure that you're working with a company that has the right expertise and background for your needs.
Unlike asphalt shingle roofs, those made of metal last for several decades, long out-lasting the life-span of the solar power system it hosts.
It is the most environmentally-friendly method of renewable energy; metal roofs and solar are recyclable and don't end up in landfills, unlike their shingle counterparts.
Overall, solar energy can be a great option if you have a metal roof and you're looking for ways to reduce your monthly expenses or reduce your carbon footprint!