Attempting to install solar panels directly on top of a lightweight tile roof is inadvisable. While they may hold up well against harsh weather, these tiles are not designed to withstand the stress of added pressure. Breaks or cracks can occur during the solar installation process, potentially compromising roof integrity and leading to leaks and other damage to your home. Drilling through these tiles may also result in damage to the base layer of your roof called the underlayment, which is used for extra protection below tiles or shingles.

Some solar installers will choose to remove individual tiles and replace them with special tile replacement mounts. Although this method may work for heavyweight tiles, lightweight tiles that are not removed are still at risk. If this method of installation is pursued and solar panels are successfully mounted without tile breakage, there is still a possibility of issues down the road. Because lightweight tiles are fragile, vibrations that occur from wind passing between the panels and the racking system sitting on top of the tiles can result in future incidents.

How do you install solar panels on tile roofs?

A preferred technique utilized to install SunPower’s highly efficient solar panels on a lightweight tile roof is called an inset solar installation, sometimes referred to as a “comp-out.” This process will add additional steps and costs to your solar project but will give you long-term durability and help prevent potential damage to your home.

During this process, a roofing professional removes the existing tile roof from the area where the solar array will be installed and lays new composite shingles in its place. Transitions are reinforced with sheet metal called flashing and sealed to ensure the roof is completely waterproof. 

Next, a solar expert installs the solar array on the composite shingle surface. Accidental harm to composite shingles that could lead to a compromised roof is unlikely, particularly in comparison to the potential of inadvertent damage to fragile lightweight tiles. 

After solar installation on the composite shingles is complete, the area around the solar array is filled in with the previously removed tiles. This creates the aesthetically pleasing appearance of the solar array being built into the roof.

What are the benefits of an inset solar panel installation?

Like other roof replacements that are a part of the solar installation process, the costs associated with solar-necessary upgrades of comp-outs may be eligible for the Solar Investment Tax Credit.

Many homeowners also choose inset installations because of the overall look. It creates the appearance that the home was designed with solar power in mind, creating a low-profile style that is often used on new home designs when solar energy is predetermined. Additionally, you get to keep the extra tiles that are removed from your roof for the composite shingle installation and can use them on future projects or repairs.

As a homeowner, you might discover that some installers of conventional solar systems will proceed with installing solar panels on a tile roof without a comp-out. However, that doesn’t mean that you should proceed with this solar installation method. Remember, these solar panels will be on your home for many years to come. That’s why SunPower provides homeowners with a 25-year industry-leading warranty. Knowledge is key. Ensure that your roof integrity is preserved by taking an active role in your upcoming solar installation. 

This post originally appeared on the SunPower Resources Blog