Will installing solar panels void my roof warranty?
Getting a 25 year warranty with your roof is typical, but what happens when your solar contractor drills dozens of holes to install a solar panel system?
Your roof keeps the rain off your head. That’s a great thing! It’s also an expensive thing to repair or replace, so you want to take care of it.
But installing solar panels typically involves drilling dozens of holes right into the roof. If you’re thinking of getting home solar panels, that might give you pause.
That’s reasonable, but there are millions of home solar installations in the United States. If roof leaks happened to even a small percentage of those, the home solar industry would have a serious problem on its hands.
So, you should be reassured that roof leaks are uncommon with a solar installation. That said, leaks can happen, but fortunately there are steps that you can take to reduce your risk.
This article will explain how solar racking systems work, how they’re attached to your roof, and steps you can take to make sure that your solar installer is doing the right thing.
When is your roof suitable for a solar installation?
In general, it’s a bad idea to install solar panels on a roof that has less than a decade of life remaining.
This is because when a roof needs repairs, the panels and racking system must be removed, stored, and reinstalled. Estimates vary, but as a very rough estimate, it might cost around $100 per panel for this remove and reinstall service. For an average sized home system, you’re looking a couple thousand dollars.
If you’re repairing your roof, that’s a cost you want to avoid. So, make sure your roof is in good condition before installing solar panels. Ideally, you want the roof to have 25 years of life remaining.
Will installing solar panels void my roof warranty?
Installing solar panels should not void the warranty on your roof if the racking system is installed according to the manufacturer’s directions. For pitched shingle roofs, which is the most common type of residential roof in use, the installation of a good racking system will include flashing and waterproofing to prevent water from penetrating the roof for 25 years or more.
Types of racking systems
There are two types of racking systems that you’ll find in use on residential homes.
For pitched roofs, the system is mechanically attached with bolts or screws that penetrate into the structure of the building.
The other type, a ballasted rack that uses weights to keep the system in place rather than fasteners, is used with flat roofs.
Good quality racking systems from major manufacturers are carefully designed so that the footing - which is the part that contacts the roof and requires either screws or bolts to be drilled into the roof deck - is protected with metal flashing and sealed with waterproofing materials.
What are roof warranties?
The warranty on your roof will normally have two parts to it.
First, there is the installer’s warranty, which will covers the workmanship of the installation itself. The duration of an installer’s warranty will vary, but 10 years is pretty common.
There will also a materials warranty that is provided by the manufacturer of the roofing product. Depending on the product, the materials warranty can range from 25 to 50 years.
Roofing failures that are due to improper installation are covered by the installer’s warranty. Defects in the roofing product are covered by the manufacturer, but only as long as the product was installed and maintained according to the manufacturer’s instructions.
For example, using spray foam insulation on the underside of the roof sheathing can cause the shingles above to get too hot, which may void the warranty.
Check with your roofer
If the installer’s warranty for your roof is still valid, consult with the roofer that performed your installation before starting any work. They will let you know if a solar installation by another contractor will void the warranty, and what requirements that your solar installer must take to prevent voiding the manufacturer’s warranty.
There are two main things that a roofer will want to know.
For footings that are mechanically attached to the roof, they’ll want to know what method will be used to waterproof the penetration.
Second, the roof structure must have enough load capacity to take the additional weight of the solar panels and its racking system, and margin for loads such as snow and wind. This is especially true for ballasted systems.
Rack systems for different types of roofs
The type of system used to attach solar panels to a roof depends on the type of roofing material. Asphalt shingles are most common, but some homes also use tile or metal.
Each rack manufacturer will have their own designs, but in general the attachment systems will look something like the examples below.
Asphalt shingles are the most common roofing product used for homes.
The footing for this type of roof involves bolts or screws that penetrate the roof deck, and flashing to waterproof the penetration. Flashing is piece of sheet metal (aluminium or galvanized steel) or EPDM (rubber) that is mounted between the footing and the roof.
A material such as caulking or butyl tape is then applied to ensure that the assembly stays waterproof for decades.
Roofing tile made of clay or slate can’t be drilled into. The most common method for installing solar panels on this type of roof is to remove the tiles and install an asphalt shingle roof underneath the tiles. This new roof provides waterproofness, while the remaining tiles around the array are there for aesthetics.
There are other approaches for tile roofs too, including hooks and replacement tiles that look like clay but provide structural support. You read my article on installing solar on tile roofs for more details.
Metal roofs might be the best type of roof for a solar installation. This is especially true for standing seam metal because the racking system doesn’t need to penetrate. Instead, this system can be clamped to the standing seam.
As a result, there’s no waterproofing work that needs to be done, and the installation on this type of roof often proceeds quicker.
Read my article on mounting solar panels on metal roofs to learn more.
If you have a flat roof, then many installers choose ballasted racking systems. These have the advantage of cheaper installation and no need to drill into the roof.
Instead, the system simply sits on top of your roof and is held in place by a heavy ballast, such as concrete blocks.
While ballasted racks have the advantage of lower cost, the one downside is the higher weight. Such as system will add about 4-5 pounds per square foot (psf) of load to the roof. It’s possible that an older roof will have trouble supporting this - but if you have an old roof, you should reconsider whether this is the right time for a solar installation.
An alternative for flat roofs is to use mechanically attached racking systems, just the same as those used for sloped roofs.
A bad solar installer can void your roof warranty
While most home contractors, whether they are electricians, plumbers, or carpenters, are skilled and ethical tradespeople, it’s an unfortunate fact that in every industry you will find a small percentage of people who perform substandard work.
This is true of the solar installer industry as well. This is why it’s important to properly screen and interview your contractors before you work with them.
Your roof warranty will in most cases not be invalided by a solar installation, but only if the installer did the work correctly and observed the guidelines provided by the manufacturer of your roofing product. A couple common ways that a solar installer can void your roof warranty include:
- Carelessness when working on your roof that leads to damage, such as cracked tiles or a compromised roofing membrane;
- The use of incorrect fasteners to attach footings to your roof;
- Low quality racking systems that don’t include waterproofing features;
- The use of a good racking system, but improper installation, such as not using the correct waterproofing sealant.
These and other mishaps can result in roof damage and costly leaks, even years later.
One of the most important things when choosing a solar installer is to understand the warranty they provide. The installer warranty should cover roofing damage, so be sure to ask about this when you meet with them.
After the installation: perform an annual check
After you’ve had a solar array installed, it’s a good idea to perform an annual check of your roof to make sure that there aren’t any issues developing.
This is actually something every homeowner should do, whether or not they have solar.
At least once a year, go up to your attic and examine the roof. For sloped roofs, you’ll see the fasteners that penetrate the roof sheathing. Look for water damage, which will be identifiable as water stains.
If you do find an issue, contact your solar installer immediately. The damage should be covered by the installer warranty.
Roofing checklist for solar installation
So the good news is that a properly installed photovoltaic system won’t damage your roof or void your roof’s warranty. In fact, solar panels can make your roof last longer by shielding it from temperature extremes and sun damage.
But there are a few things to do to ensure that the installation goes correctly. Here’s a cheatsheet:
- Know how old your roof is. If it’s under warranty, check with the roof installer before installing solar panels.
- If the roof has only about 10 years of life left, consider delaying an installation until you can do a roof replacement at the same time.
- Know what your roofing product warranty is, and make sure that your solar installer understands how to work with your type of roof.
- Understand what your solar installer’s warranty is, and make sure that it covers damage to the roof.
- Ask what type of racking system your installer will be using, and make sure that it’s itemized in your quote.
- Ask the installer what materials and steps they take to ensure that their installation remains watertight.
- If your installer is proposing a ballasted system, make sure that the project has an engineering review that confirms that your roof can support the additional live load.