What Type of Roof is Best for Solar Panels?

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Homeowners and businesses across Arizona are growing more environmentally-conscious with each passing year. More and more people are finding ways to reduce their carbon footprint, whether that’s by increasing energy-efficiency, carpooling to work, or reducing waste. Each of our efforts adds up to make greener, healthier, and more sustainable communities. 

One of the biggest steps homeowners are taking for sustainability is looking into solar power. With more than 300 days of sun each year in Arizona, we have a unique opportunity to cash in on this abundant resource. It’s no wonder that our state is one of the fastest-growing places for solar adoption. 

Before you start planning your solar installation, however, you need to think about your roof. Solar panels and rooftops go hand-in-hand, and there’s a lot to consider – from the health of your roof to how suitable different roofing materials are to solar. In this guide, we’ll explore why roof assessments are an essential part of the solar panel installation process, what type of roof is best for solar panels, and how to determine if your roof is suitable for solar. 

Why it’s important to inspect your roof before solar installations

Before we begin discussing the best roof types for solar, let’s talk about roof health. It’s absolutely essential to have your roof inspected before installing solar power for several reasons.

Avoid expensive removal and reinstallation

Solar panels are designed to last for decades, and you want to make sure that your roof provides a sturdy foundation to support this technology for its entire lifespan. If your roof isn’t healthy before the panels go up, and you find out five years later that a repair is needed, you’ll face the costly process of needing to remove and reinstall the solar panels before you can even look at the roof underneath. 

Most solar warranties only cover roof damage that's directly related to the solar installation, which means this expense will fall entirely on you. 

Improve solar panel efficiency 

Well-ventilated roofs can make solar work more efficiently by cooling the ambient temperature and reducing the strain on your solar panel system. During the scorching Arizona summers, poorly-ventilated roofs can become extremely hot and increase the temperature of your home. This means you'll be cranking up the HVAC system and exerting more power from your solar panels. A properly ventilated roof can keep temperatures down naturally and prevent overtaxing your AC system and solar panels, boosting overall efficiency and keeping those electricity bills low. 

What’s involved in a pre-solar roof inspection?

Roofing inspections are typically free and can include checking:

• Roof age: Evaluating whether your roof is nearing the end of its lifespan. 

• Tile condition: Looking for broken, missing, or damaged roof tiles. 

• Ridge capping: Checking for damaged ridge capping. 

• Underlayment: Inspecting underlayment, which is the material that sits between the wood frame and roof coverings. 

• Leakage: Looking for signs of water stains or potential leaks inside your home. 
• Structural integrity: Making sure your roof is able to support the additional weight of solar panels. 

Most reputable solar companies will assess the health of your roof before selling you rooftop solar panels. But for the most reliable assessment, we recommend contacting a licensed roofer. Even better if they have experience in roofing for solar panels. 

Contact us for a free, no-obligation roof evaluation. 

Best roof types for solar panels

Now that you understand the value of a pre-solar roof inspection, let’s take a look at some of the best roof materials for solar panels. 

Foam roofs

Most flat roofs in Arizona utilize foam roofing for its durability, ease of installation, and overall efficiency. This type of roof material is more popular in commercial applications, but it’s growing increasingly common in the residential sector as well. Foam roofs are coated with a white, reflective UV layer that helps prevent heat from absorbing into the building. This can reduce the load on HVAC systems and further lower electricity bills. 

Installing solar panels on a foam roof is extremely simple but requires a tilted racking system to ensure proper angles for optimal sun exposure. Because of this, the mounting hardware may cost a bit more, but other than that the overall installation is still fairly simple. 

Keep Reading: Four Ways Your Roof Can Cut Your Electric Bill

Flat rolled roofs (BUR)

Built-up roofing (BUR), common in both residential and commercial settings, is another type of roofing that’s relatively simple for solar installations.The main drawback of these roof types is that they absorb and hold heat, which can translate to a higher electricity bill. Due to the heat and sun exposure, they also tend to have a lower life expectancy than other roof materials – typically about 15 years.

The good news is that there are ways to help mitigate this heat absorption. Arguably the most popular option is to foam over your existing one layer BUR roof or apply a coating prior to installing solar. Coating options include acrylic, which requires a recoat every 5 years, or silicone, which only needs to be recoated every 20-25 years. We recommend the silicone option since it requires less maintenance and lasts significantly longer, which also helps you save panel removal and reinstallation costs if a roof repair is needed and panels are in the way. 

As with flat foam roofs, solar panels on a BUR roof will typically be installed with tilt racking to maximize sun exposure and energy production.

Tile roofs

You see these roofs everywhere here in the Valley of the Sun for a variety of reasons. Tiles are resilient under the harsh Phoenix sun, their aesthetic aligns with local Southwestern preferences, and they are durable under stress from the elements. In addition, tile roofs generally absorb less heat, keeping your attic and home cooler. They also have a lifespan measured in decades – which helps to reduce the amount of worn roofing material from making its way into landfills. 

Roof tiles can be made from different materials, including clay, ceramic, metal, slate, concrete, and synthetic cedar. The type of material they’re made from can affect your solar installation. For example, it’s easier (and therefore cheaper) to install panels on concrete tiles compared to clay tiles. Properly trained solar installers will find tiles simple to work with, as they can easily be isolated and removed to accommodate racking standoffs. However, they do come with a few challenges. 

Roof tiles are significantly heavier than other roofing materials. This can make solar installations slower – and therefore more costly. They also require special mounting hardware with special replacement tiles designed to work with the racking standoffs. This helps provide a secure fit while still preserving the general aesthetic of your roof. Finally, tiles can easily break if solar installers aren’t careful about where and how they step. 

For all these reasons, make sure to choose a reputable solar installer with plenty of experience working on tile roofs and a good penetration/workmanship warranty to boot. Experienced solar companies will even be able to install panels on clay or sandcast tiles.

See More: 4 Benefits to Working with a Solar Roofing Company

Asphalt shingle roofs

Shingles are one of the most popular roof types due to their competitive price and numerous color options and general durability. Asphalt shingles are also one of the easiest roof materials for solar installation. If you’re looking to add an additional ‘green’ element to your roof – even before you go solar – there are some shingles manufactured from recycled or recyclable materials. This can help reduce the environmental impact of replacing or repairing this kind of roof. 

That said, asphalt roofs come with a few drawbacks in our harsh Arizona heat. When it comes to solar, asphalt shingles can trap heat beneath the panels and cause them to work less efficiently during the hotter seasons. Heat absorption can also impact the overall temperature of your home, forcing your AC system to work harder.. Reputable solar installers will know how to set the appropriate airspace between the roof and the solar panel in order to provide ample ventilation for maximum power generation. What’s more, solar panels can also provide shading, reducing the amount of heat build up on the roof by blocking the path of the sun. 

Asphalt roofs also tend to have a shorter lifespan than other roofing materials – usually between 12 and 30 years. Knowing which roofing materials last the longest is extremely important when considering solar since you don’t want your solar system to outlive your roof. Remember, if you need to repair or replace your roof in the future, you’ll likely need to pay solar panel removal and reinstallation costs. 

Since modern solar panels are warrantied for up to 30 years – with an operational lifespan well past that mark – picking a high-quality, long-lasting roofing material is the best way to avoid unexpected costs down the road. 

See: Asphalt Shingle Roofs: The Pros & Cons

Metal roofs

Metal roofs are another roof type that’s suitable for solar panels. These roofs can last anywhere between 40 to 75+ years, are non-flammable, and can be energy-efficient if the metal is a light color. This can reflect heat and light away from your home and help keep temperatures lower. 

That said, installing metal roofs can be costly, and adding a solar installation also comes with additional complexity. Like foam or BUR roofs, metal roofs require different racking equipment, so it’s important to choose a solar installer with experience working with this material. 

Standing seam metal roofs can allow for a more efficient solar panel installation, since the panels can be attached directly to the seams. This removes the need to drill holes, which can speed up the installation and reduce labor costs. 

Is your roof suitable for solar?

When assessing your roof’s suitability for solar, you need to consider more than the material it’s made from. Factors like roof angle, orientation, and size can all affect solar panel efficiency and can help you decide if solar power is suitable for you. While you don’t need the perfect home to get enough benefits from solar, it helps to understand what factors can affect output and electricity generation. 

Below are some things solar installers will consider when assessing your roof’s suitability for solar. 

Roof angle

Your roof’s angle can play a role in how much electricity you generate. In most cases, the best roof angle for solar panels is about 30 degrees, but this can change slightly depending on where you live. According to the U.S. Department of Energy, solar panels perform best when tilted between 15 and 40 degrees. 

As a general guideline, solar panels should be tilted as close to the sun as possible for maximum absorption, so the ideal angle is usually close to your home’s latitude. 

Roof orientation

The direction your roof faces can also play a role in how much electricity your solar panels generate. In the northern hemisphere, the best direction for solar panels to face is south (and opposite for the southern hemisphere). This means your panels will enjoy maximum sun exposure throughout the day, for the most electricity generation. 

However, even with an east, or west facing roof, it is still possible to generate enough solar power to meet your production goals and make solar worth it. A good solar installer will be able to tell you how much electricity you can realistically generate from the size, angle, and orientation of your roof. 

Roof size

Finally, the size of your roof determines how many solar panels you install. If your roof doesn’t have enough surface area, or there are obstructions from chimneys or other structures, you may not be able to install enough solar panels to meet your electricity needs. 

Generally, a standard residential solar panel will require about 20-22 square feet of space, including space for mounting and maintenance access. If a typical 7kW solar system requires about 18 panels, you’d need about 360-400 square feet of roof space. 

However, each home is different and the size of your solar array will depend on your energy needs and the efficiency of your solar panels (more efficient solar panels means you might need less panels overall). 

Local Arizona solar installer

If you’re ready to explore your options with solar, we’ve got you covered with a reputable solar company that’s trusted in our local area. Sun Valley Solar Solutions is our sister company, with more than a decade’s years experience installing commercial and residential solar energy systems in Arizona. They provide free, no-obligation solar consultations to help you determine whether solar power is right for you. 

If you’re planning a solar installation and want to have your roof looked at beforehand, contact us today for an honest roof evaluation.