Can Solar Panels Damage Your Roof? Here’s the Definitive Answer

solar panels

One of the most common concerns homeowners have when considering getting solar panels is if installing them on their roof will damage it. The short answer is no, but some key factors are involved and make this topic more nuanced. We will cover everything you need to know about installing solar panels on your roof and how we ensure it doesn’t get damaged.

First, Assess Your Roof’s Current Condition

Installing solar panels on a roof that is already in poor condition can worsen things. A professional installer will be able to determine if your roof can bear the solar panel racking once installed, but these are some aspects you need to keep in mind:

  • Age: If your roof has a remaining lifespan of 25 to 30 years, it is a good candidate for solar panels. A properly installed solar system has the same average lifespan, so the roof holding it should have a similar life expectancy. If your roof is old and will need maintenance in the near future, it is best to do so before installing solar panels.
  • Structural integrity: Solar panels are heavy. They weigh 40 pounds on average. As a rule of thumb, they add 2.8 pounds per square foot on inclined roofs and five pounds per square foot on flat roofs. A professional solar installer should perform a roof assessment. At Solar YYC, we evaluate our clients’ roof condition before installation with the help of a drone and specialized software for free.
  • Roof orientation and inclination: A roof facing south or southwest with an inclination of 20 to 50 degrees is a good candidate for solar. If your roof faces east or west, panels will work but may produce slightly less energy. If you have a flat roof, you can install solar panels, but you need to be aware that the panels will require a special mounting system.
  • Roofing material: When it comes to the best roofing materials for solar, there are a few factors to consider:
    • Resistance: the shingles should withstand the weight of the solar panels and any potential debris that may fall on them during installation or maintenance.
    • Solar reflectance: the shingles should have high solar reflectance to reduce heat absorption and improve the panels’ efficiency.

Roofs with asphalt shingles (also known as composition shingles) are the best candidates for solar panels. They are made of a mix of fiberglass or cellulose, asphalt, and other mineral granules, which makes them very flexible, resistant, and durable. This type of shingles also has the best solar reflectance among the solar-approved shingles. Other suitable roofing shingle materials for solar panels are some types of metal, tar and gravel.

On the other hand, if your roof has shingles of any of these materials, solar panels may not be ideal:

  • Cedar: these shingles are not as durable as other materials and can be damaged by heavy loads. Additionally, their uneven surface may make it harder to achieve a seamless installation.
  • Clay and concrete: although installing solar panels on roofs with these materials is possible, extra care is needed. These materials can be heavy and brittle, making them prone to cracking and breaking during installation and maintenance.
  • Slate: this material is heavy and often requires drilling holes through the tiles, which can cause damage.
  • Some types of metal: even though metal is often a great candidate to bear a solar system, there are some exceptions. For example, standing seam metal may require clips or brackets to attach the racking, creating a visible gap between the roof and the panels. This can make the installation less aesthetically pleasing and may reduce the panels’ efficiency.

Get Your Roof Solar-Ready

If the assessment determines that your roof’s current condition is not ready for solar panels. Here are some things you can do:

  • Repair and maintenance: the solar company you are working with or the contractor that inspected your roof should be able to give you the details of the required repairs and maintenance work your roof needs to install the panels successfully. For example, if you need to do some reinforcement work, sistering the rafters to increase your roof’s strength may be an option.
  • Replace your roof’s shingles: if your roof’s shingles are not ideal for holding solar panels, replace them with solar-approved ones.
  • Clean the roof: With Calgary’s dry and windy climate, you’re not likely to find moss or ivy growing over your roof. However in some jurisdictions, homeowners need to ensure the roof is free of any debris or plant material that may interfere with the installation. A clean surface will also ensure the panels are installed flush with the roof.

What About Ground-Mounted Solar Panels?

You may want solar panels, but if you’re not ready to invest in extra roof prep, ground-mounted solar panels can be an option to consider. However, this option works best on farms or properties further away from urban areas because the extra buildings often bring extra shade. 

Solar Panels Won’t Damage Your Roof If They’re Properly Installed

Now you know that solar panels shouldn’t cause any damage to your roof; however, a good roof inspection and the advice of a professional installer are essential to go solar successfully. 

Working with a seasoned solar company will give you the peace of mind that you’re getting sound advice, that your home’s integrity is being taken care of, and that you’ll have support when you need it after getting your solar system.

If you’re ready to go solar and want to know your roof’s condition, contact us for your free assessment.