Should You Replace Your Roof Before Solar Panels? (LA Guide)

Should you replace your roof before solar panels go on? Homeowners ask us this a lot, usually as "should I replace my roof before installing solar panels?" If the roof is 10 or more years old, or has any problems, yes. Solar panels last 25 to 30 years. Nobody wants to pay to take them off in year eight because the roof under them gave out. We're a family-owned roofer in the San Fernando Valley, and we've built roofs for solar installs, like this Encino home. Below, we explain how to decide, what it costs to do it in the wrong order, and how a roof gets built for panels.

One thing up front: we don't sell or install solar panels. We do roof replacements. So this is a roofer's answer, not a solar pitch.

Should You Replace Your Roof Before Solar Panels?

Replace the roof first if it is 10 or more years old, if it leaks, or if it has fewer than 10 years left. A new roof and new panels then wear out on about the same schedule. If the roof is newer and in good shape, you can usually install solar right on it.

The reason is simple. Solar panels are built to last 25 to 30 years. EnergySage, a site that compares solar quotes, says a shingle roof over 10 years old should probably be replaced first. ConsumerAffairs gives a wider range, 15 to 20 years, for a roof that's still in good shape. Either way, the question is the same: will this roof outlast the panels?

For example: say your shingle roof is 14 years old. Shingles here usually last 20 to 30 years. So that roof might have 6 to 16 years left. The panels will still be working in year 20. Somewhere in there, the panels come off for a re-roof. You pay for that twice: once to remove them, once to put them back.

How Old Is Too Old For A Roof To Go Under Solar?

There's no single age. It depends on the roof type and what shape it's in. Here's the rough guide we use, with the typical roof and panel lifespans in mind:

A tile roof is the tricky one. The tiles themselves may look fine, but the waterproof sheet under them, the underlayment, is what keeps the house dry. On older Valley homes, that sheet is often worn out while the tiles look new. We replaced the underlayment under a tile roof in Agoura Hills for that reason.

An inspection settles it. It takes about an hour. A roofer can tell you how many years the roof has left. Get that answer before you sign a solar contract, because once the panels are on, every roof repair costs more.

What Does It Cost To Replace A Roof After Solar Panels Are Installed?

A roof replacement with solar panels already installed costs more than a plain re-roof, because the panels have to come off and go back on. EnergySage puts solar panel removal and reinstallation at about $200 to $300 per panel. For a typical home system, that's roughly $1,500 to $6,000. Then add the roof itself. And the days your panels aren't producing power.

So what if you need a new roof after going solar? It can be done, but it costs more and takes two crews. Here's how the two orders compare, and the benefits of replacing the roof first:

The costs above are from EnergySage and depend on your system and your installer. Ask your solar company for its removal-and-reinstall price in writing before you decide.

Who Can Do The Work In Los Angeles?

In California, a solar company can't re-roof your house, and a roofer can't remove or reinstall your solar panels. Each job needs its own licensed contractor and its own permit. That rule matters most when you do the roof later, but it also tells you who to hire now.

Los Angeles County's building department spells it out. Its re-roofing rule says the state license board requires a C-39 roofing contractor for the roof. The panels need a C-10 electrical or C-46 solar contractor. Agoura Hills, in our service area, says the same. Its policy requires a separate permit for each job, and adds that "a C-46 solar contractor is not licensed to do the re-roofing work."

So if a solar company offers to "include a new roof," ask who is doing it. Then look up that company's license on the state license board's site. You want a C-39 or a B license on the roof. Ours is CSLB C-39 #910673.

Here's the order the jobs go in when the roof comes first:

We pull the permit on every re-roof. Your solar company pulls theirs.

How Is A Roof Built For Solar Panels?

A solar-ready roof has its mounts planned before the roof is finished. That way every hole is sealed by the roofer, not drilled through a brand-new roof afterward. On a shingle roof, that means knowing where the mounts go. Each one gets flashing, a metal collar sealed so water can't get in. A flat roof is different: the solar crew may come in between the roof's layers.

Real example: on an Encino home, we put on a whole new roof before the solar install. The sloped part got about 2,800 square feet of dark Owens Corning shingles. The flat part was 1,600 square feet. The flat roof got two heat-sealed layers. The solar company set its brackets on the first layer, and our white top layer went over them. The finished roof has no holes from the solar install.

Here's how that flat roof went together:

Holes are where flat roofs leak. Building experts give the same advice: plan the solar mounts before the roof is finished, so the roofer can seal them. That only works if your roofer and your solar company are talking before the job starts. We'll do that with yours.

Does A New Roof In Los Angeles Have To Be A Cool Roof?

On most homes, yes. The City of Los Angeles requires a cool roof, one that reflects more sunlight, when more than half of the roof is replaced (LA green building code summary). A full re-roof always crosses that line. Nearby cities like Burbank and Glendale follow California's Title 24 energy code, which has its own cool roof rules.

That doesn't mean a white roof. Dark can pass too. Owens Corning makes cool shingles in dark colors, rated by the Cool Roof Rating Council, the group that tests cool roofing. The Encino home used a color called Midnight, and it passed. Flat roofs have a higher bar, which is why they're almost always white. Our cool roof page covers the options.

A cool roof also helps the panels a little. Panels lose some output as they heat up, and a roof that reflects heat runs cooler underneath them. The bigger win is the cooler attic.

When You Don't Need A New Roof Before Solar

If your roof is under about 10 years old, has never leaked, and passes an inspection, go ahead with solar. Skip us. A new roof you don't need is money you could put toward the panels. We'll tell you that during the estimate if it's true for your home.

Three things still matter on a newer roof:

• Get the inspection anyway. It's the only way to know the roof's condition, and it gives you a record of the roof before the panels go on.
• Ask who fixes a leak at a mount. Get it in writing from the solar company. Their mounts are the new holes in your roof.
• Keep your roof warranty paperwork. Shingle systems usually come with a manufacturer warranty, and ours add a 10-year workmanship warranty. Exact terms depend on the product and are in your estimate. Know what each one covers before another company drills into the roof.

Checklist Before You Sign A Solar Contract

• Have the roof inspected by a licensed roofer, not only the solar company's salesperson.
• Ask for the roof's remaining life in years, in writing.
• If it's 10 years old or more, get a re-roof quote and compare it with the cost of moving the panels later.
• Check every license on the state license board's site: C-39 or B for the roof, C-46 or C-10 for the panels.
• Get the two companies talking about dates and, on a flat roof, about the mounts.
• Pick a roof color that passes your city's cool roof rule.
• Confirm who pulls each permit. Two jobs, two permits.
• Don't count on a tax credit for the roof. The IRS says traditional shingles and framing under solar panels don't qualify, and the federal residential credit ended for systems placed in service after December 31, 2025.

Planning A New Roof Before Solar In The San Fernando Valley?

We replace roofs across the San Fernando Valley, including Encino, Sherman Oaks, Northridge and nearby cities like Burbank and Glendale. Our own crews build shingle, tile, flat and cool roof systems, and the permit gets pulled on every re-roof. Book a free estimate. We'll tell you whether your roof should come first, and if it should, we'll plan the dates with your solar company.