What is the Best Roof for Solar Panels?
Solar energy isn’t just what you use to power on a few porch lights or a watch. Today, solar energy is harnessed more and more as a way of going green and saving money. There are now close to 2 million solar installations in the U.S., and that number is expected to double by 2023.
One reason people are now installing solar panels in increasing numbers is that it has become much more affordable to do so. In fact, the cost has come down by more than 70% in the past eight years. Additionally, you can enjoy tax incentives, including the federal Investment Tax Credit (ITC) and, in many cases, state tax breaks, as well.
If you are one of the many American homeowners who care deeply about the environmental benefits of cleaner energy, then there has never been a better time to consider installing solar panels on your roof. Solar panels can help your home become more energy efficient, which also increases the value of your home, all while helping the environment. If you’re looking into having solar panels installed on your roof, you likely have some questions, such as “can I put solar panels on my type of roof” and “how will solar panels affect my roof?” Let’s take a look at some answers to these common queries.
Do I Need A New Roof Before I Put Solar Panels On?
Whether you need a new roof for your solar panels depends on a few factors, but the main factor to consider is the condition of your current roof. Your roof should be fairly new and in good condition if you’re going to install solar panels on it.
According to the National Association of Home Builders (NAHB), asphalt shingle roofs — by far the most popular roofing material — last about 20 years. Of course, condition does not always directly correlate with age, so it’s important you know not only how old your roof is but also what sort of shape it’s in currently. Especially if your roof is more than five years old, you should consider having a professional evaluation done on your roof to help determine whether it is holding up well and is ready for solar panels.
If your roof is nearing the end of its projected lifespan or is in poor condition, then you are typically better off replacing it before installing solar panels. This ensures your roof will be able to support the solar panels, which weigh about the same as adding a second layer of shingles, and keeps you from having to pay to take down the panels when it comes time to replace the roof and reinstall them after the new roof goes on.
Most solar panels last 25-30 years or more, so you don’t want to install them on a roof that will need to be replaced long before they do. If you find that you need to update your roof in order to install solar panels, you can include this expense in your tax credit. You should also research what types of roofs work best with solar panels. If you’re worried about the expense of a new roof, remember, having solar panels installed can eventually save you tens of thousands of dollars, so it’s a good investment.
Is My Roof Compatible With Solar Panels?
Whether you’re thinking of installing solar panels on your current roof or re-roofing first, there are a few things to consider to make sure your roof will accommodate solar panels. The good news is most types of roofs are compatible with solar panels. However, roofs today aren’t usually installed with solar in mind, so you may have to make some adjustments to your current roof. Or, if you’re installing a new roof, you can keep these factors in mind in order to optimize your new roof for a solar installation.
Besides the age and condition of a roof, the main aspects that affect its compatibility with solar panels are:
- Material
- Pitch
- Shape and size
- Orientation
- Amount of shade
Let’s take a quick look at each of these factors.
Material of Roofing
Many people wonder whether solar panels hurt their roof? Fortunately, most roofing materials can accommodate a solar panel installation without harming the roof itself. First, let’s focus on the most common roofing material — asphalt shingles, also called composite roofing. Asphalt shingle roofing works great for solar panels and involves a simple installation process. Tile roofs are also highly compatible with solar panels and make them easy to install. The roof type that is most compatible with solar panels is a standing metal roof. The standing seam allows for easier and cheaper installation without drilling into the roof.
Roofing materials that are not ideal for solar include wood and slate roofs. For one, these roofing materials are brittle, so solar panel installers can’t just walk around on the roof as they normally could. This makes for a more difficult and, therefore, more expensive installation process. Another concern with installing solar on a wooden shingle roof is that it can present a fire hazard.
Pitch of Roofing
The pitch, or angle, of your roof is also something to consider. Roof pitch is determined by the vertical rise divided by the horizontal run. Most people consider the ideal angle for a solar panel to be 30 degrees. This translates to a roof pitch of about 7/12, meaning for every 12 inches of space horizontally, the height of the roof increases by seven inches.
If you have a steeper roof, then it will likely still work for solar panels and won’t have much of an effect on your energy production. For example, a tilt of 40 degrees should only decrease energy production by about one percent compared to 30 degrees. However, anything over 40 degrees is probably too steep. In addition to the system’s efficiency, another important concern with steep roofs is that contractors may not be able to safely install the panels.
If your roof is flat, then you can still install solar panels. It just means you’ll have to use brackets to angle the panels, which can cost a little extra. The way solar panels are installed on a flat roof also depends partly on the material atop the roof, i.e. tar and gravel, PVC, etc.
Shape and Size of Roof
The shape and size of your roof can also affect its compatibility for solar panels. The average residential solar system in the U.S. is 5 kilowatts, which requires at least 300 feet of surface area on your roof. The best shape and size for solar panels is a large, square roof because it makes for a simple installation. A straight measurement of the size of your roof won’t tell you everything you need to know, since anything that interrupts your roof’s surface, including dormers, chimneys and other features, can affect your available space.
Since roofs can come in near infinite configurations of shape and size, you should consult a contractor who can take a look at your roof and give you some feedback on whether solar panels would fit well and how much of your roof surface can be equipped with panels.
Orientation of Roof
In the northern hemisphere, solar panels work most effectively when they face true south. Note that this is not exactly the same as the magnetic south direction indicated on a compass. A great way to find out which direction your house faces is to look for your address on a platform like Google Maps. This will tell you which direction is true south and how the orientation of your house compares.
Even if the orientation of your house prevents you from having your panels face south, you can still have a lot of success with southwest- or southeast-facing panels, especially if you receive a good amount of sunlight. You can also request your contractor use a rack when installing the panels in order to adjust their orientation.
Shade Around Roof
The amount of shade around your roof can also impact the effectiveness of solar panels. In some cases, shade cannot be altered. For example, if your house is shaded by other buildings, there’s not much you can do about this. If your roof receives minimal sunlight, then solar panels may not be a great option for you.
Some sources of shade can be taken out if need be. For example, if you have large trees on your property that block parts of your roof from the sun, you could cut these trees down entirely or trim them back. If you’re not sure whether shade will be a problem for your roof, consult your contractor. Ask if any trees or other obstructions near your home may have an effect on how well solar panels would work on your roof.
How Do Solar Panels Attach to My Roof?
Solar panels can attach to roofs in different ways. The attachment method used will depend mainly on the material and the pitch of your roof. In most cases, with the exception of standing seam metal roofs, solar panels are mounted with a system that drills into the rafters. Let’s take a look at some common setups:
- Asphalt Shingle Roof: For asphalt shingle roofs, solar panels are attached with a standard penetrating mount, which is easy to install.
- Tile Roof: Solar panels can be installed on tile roofs with a standard penetrating mount that raises them above the roof. Attaching solar panels to a tile roof can require some extra labor since tiles may need to be cut or removed to make way for the mounts.
- Standing Seam Metal Roof: The raised seam allows solar panels to be attached with a clamp, so there’s no need to drill into the roof.
- Flat Roof: On flat roofs, either a ballasted racking or standard penetrating mount can be used to install solar panels. Tilt-up brackets are used to keep solar panels at a 30-degree angle.
Some homeowners may be concerned about drilling into their roofs. However, the stanchions used to mount panels to rafters are flashed, which keeps water from leaking into your home.
How Do Solar Panels Affect My Roof?
Not only do you not have to worry about solar panels damaging your roof, you can actually look forward to them protecting your roof. Solar panels are like armor that protects your roof from exposure to the elements. Being protected from ultraviolet light, rain, hail and other forces that contribute to wear means your roof should last longer than it would otherwise.
Another nice perk is that your attic won’t get as hot since your roof will be shaded by the panels. One study found that, under solar panels, the temperature of a building’s ceiling stayed five degrees cooler than the ceiling of a building without solar panels on the roof. Shading your home’s interior means your air conditioning won’t have to work as hard to cool your home, which can save you even more on your energy bills.
Of course, as with any type of contracting work, you should take all necessary measures to make sure your solar panels are installed properly. Issues like leaking typically only occur when the job isn’t done right.
Does Installing Solar Panels Affect My Roof Warranty?
So, we’ve established that — as long as they’re installed correctly — solar panels can actually have a beneficial effect on your roof, but you may still be wondering about whether installing solar panels could void your roof’s warranty. That is an important thing to consider.
The answer is simple in some cases. Mounting systems that do not penetrate your roof, which includes ballasted racking and roof clamp racking, will not have an effect on your roof’s warranty. For penetrating systems, you should take a couple important steps in order to make sure you don’t void your roof’s warranty:
- Talk to Your Roofer: You should inform your original roofing contractor of your plans to install solar panels and ask about whether this will have any impact on your warranty. In some cases, to protect your warranty, you may need your roofer to prepare your roof for the installation process by removing shingles or tiles where mounts will go. This will require your roofer to coordinate with the contractor installing your panels.
- Hire a Qualified Contractor: Even if your roofer helps to prep your roof, it is still vital that contractors installing your solar panels have the experience and expertise to do a quality job and avoid damaging your roof in any way. Even denting your roof slightly could void your warranty since this can have a long-term effect on your roof’s effectiveness. Ask your contracting company if it can guarantee your roof won’t be damaged, keeping your warranty intact.
What’s the Next Step in Installing Solar Panels?
If you’re interested in having a new roof installed or have questions about installing solar panels on your current roof, contact the roofing experts at Sunshine Contracting Corp. We rank in the top two percent of roofing contractors in the nation and have been recognized through multiple certifications and awards for the outstanding work we consistently deliver.
We offer roofing services in Arlington, Fairfax, Prince William, Loudoun, Stafford County and the surrounding areas. We are happy to answer your questions online, over the phone at 703-935-4663, or in person through a free consultation at your home.
If you decide not to install solar panels but are looking for other ways to improve your home’s energy efficiency, ask us about installing new doors and windows that could help lower your energy costs and reduce your home’s carbon footprint. And if you are interested in having solar panels installed, it’s still worth considering new windows and doors to maximize your home’s energy efficiency. Whatever your contracting needs, Sunshine Contracting Corp can get the job done.
