After 10,000+ installations across Oahu, here is what we know about which roofs hold up — and which ones cause problems — under solar panels in island conditions.
We ripped a solar array off a house in Ewa Beach last year that should never have been installed in the first place. The homeowner had paid a budget company to mount 22 panels on an asphalt shingle roof that was already 18 years old. Three years later, the shingles underneath were crumbling — UV-baked, salt-eaten, done. She had to pay for a full tear-off, a new roof, and a reinstall of the solar system. The total bill was nearly double what it would have cost to replace the roof and install solar at the same time.
That job stuck with our crew because it was preventable. The original installer either did not inspect the roof or did not care. We care, because we are a licensed roofing contractor as well as a solar installer, and we have seen what every roofing material on this island does after 10, 20, and 30 years under Hawaii's sun.
Your roof is the foundation of your solar investment. Get the pairing wrong and you are looking at a costly do-over. Get it right and your panels and your roof work together for decades.
Before we get into specific materials, you need to understand what makes roofing in Hawaii a different game entirely. The National Renewable Energy Laboratory's solar resource data shows that Hawaii receives some of the highest UV radiation levels in the United States — an annual average of 5.0 to 5.5 peak sun hours per day on Oahu.[1] That UV intensity is phenomenal for solar production. It is brutal on roofing materials.
Then there is salt air. If you live within a mile of the coast — and on Oahu, that covers neighborhoods from Hawaii Kai to Kapolei, from Kailua to the North Shore — airborne salt is actively corroding metal components and degrading organic materials every single day. Trade winds carry that salt mist inland, which means even homes in Mililani and Pearl City get more salt exposure than a typical mainland house ever would. Add 40 to 60 inches of annual rainfall on the windward side (Kaneohe averages over 50 inches), and you have a recipe for accelerated aging on every roofing material made.
The upshot: a roofing material rated for 30 years on the mainland might last 20 here. Sometimes less. When you are installing solar panels that will produce electricity for 25 to 30 years, you need a roof that will outlast them.
Roughly 60% of the residential roofs we work on in Oahu are asphalt shingle. It is the default choice for tract homes, and every subdivision built from the 1970s through the 2000s — Mililani, Ewa Beach, Kapolei, Royal Kunia — is dominated by architectural shingles. They are affordable, they look fine, and they are familiar to every roofer on the island.
The problem is lifespan. A 30-year architectural shingle in Hawaii realistically lasts 15 to 22 years.[2] The constant UV bombardment breaks down the asphalt binder and dries out the granule adhesion faster than in temperate climates. We have pulled shingles off homes in Ewa Beach that were 16 years old and looked like they had been through 25 mainland winters. Cracked, curling, granules gone.
For solar, asphalt shingles require penetrating mounts. Our crews drill through the shingle and decking, bolt the racking standoffs into the rafters, and seal each penetration with flashing and roofing sealant. On a sound roof, this is completely watertight and code-compliant. On an aging roof, every penetration is a potential failure point once the surrounding shingles start deteriorating.
Here is our rule: if your asphalt shingle roof is less than 5 years old, install solar and do not think twice. If it is 5 to 10 years old, get it inspected first — we will tell you honestly whether it has enough life left. If it is over 10 years old in Hawaii conditions, replace it before you put panels on top of it. The math always favors doing both at once over pulling panels off in seven years for a reroof.
| Roofing Material | Hawaii Lifespan | Solar Mount Type | Installed Cost (per sq ft) | Solar Compatibility |
|---|---|---|---|---|
| Asphalt Shingle | 15–22 yrs | Penetrating | $3.50–$5.50 | Good (if roof is new) |
| Standing Seam Metal | 40–60 yrs | Clamp (no penetrations) | $8.00–$14.00 | Excellent |
| Concrete Tile | 30–50 yrs | Tile hook + penetrating | $6.00–$10.00 | Good (specialized install) |
| Clay Tile | 40–60 yrs | Tile hook + penetrating | $10.00–$18.00 | Good (fragile, heavier labor) |
| Flat / Mod-Bit | 15–25 yrs | Ballasted or penetrating | $4.00–$8.00 | Good (commercial standard) |
Cost ranges reflect 2026 Oahu pricing including materials, labor, and removal of existing roof. Actual costs vary by roof size, pitch, and access difficulty.
This is our professional recommendation, and we will not hedge it. If you are building a new home, replacing an old roof, or planning a roof-plus-solar project, standing seam metal is the best material you can put under solar panels in Hawaii.
The reasons start with how solar attaches to it. Standing seam metal roofs use raised interlocking seams that run vertically from ridge to eave. Solar racking clamps directly onto those seams — no drilling, no penetrations, no holes in your roof. The S-5! and EcoFasten clamp systems grip the seam mechanically, and the panels float above the roof surface with an air gap that actually helps cool both the panels and the roof underneath. On a hot Kapolei afternoon when ambient temperature hits 90 degrees, that air gap matters. NREL research on rooftop PV thermal effects has documented that solar panels can reduce roof surface temperatures by 5°F on average, extending roofing material life[3] — and metal roofs benefit the most from this effect because they are already reflective.
Then there is longevity. A quality standing seam metal roof with Galvalume or aluminum panels lasts 40 to 60 years in Hawaii. That is two to three times the lifespan of asphalt shingles. Your 25-year solar warranty expires and the metal roof is still going. No mid-life reroof, no pulling panels, no reinstallation cost.
Salt air resistance depends on the metal and coating. We recommend aluminum standing seam or Galvalume (steel with aluminum-zinc alloy coating) for any home within three miles of the coast, which on Oahu is essentially everywhere. Pure galvanized steel corrodes fast in salt air — we have seen it fail within 10 years in Kailua. The premium for aluminum over steel is typically 15–20%, and it is worth every dollar on an island.
The objection we hear most is cost. Standing seam metal runs $8 to $14 per square foot installed, versus $3.50 to $5.50 for architectural shingles. On a 2,000-square-foot roof, that is a difference of $9,000 to $17,000. But amortize it over a 50-year roof life versus a 20-year shingle life and the metal roof is actually cheaper per year — before you even factor in the avoided cost of pulling and reinstalling solar panels for a mid-life reroof. Add the energy savings from metal's reflectivity (lower cooling costs) and the zero-penetration solar mounting, and the total cost of ownership is not close.
Tile roofs are common in certain Oahu neighborhoods — you see a lot of concrete tile in Hawaii Kai and Waikele, and clay tile on higher-end homes in Kahala and Portlock. Both materials perform well in Hawaii's climate. Concrete tile handles UV and salt exposure with minimal degradation, lasting 30 to 50 years. Clay tile can last even longer, 40 to 60 years, and its fired ceramic surface shrugs off salt air like it is not there.
The challenge with tile is installing solar on top of it. Tiles are brittle. Walk on them wrong and they crack. Our crews use specialized tile hook mounting systems that require removing individual tiles, installing brackets anchored to the roof deck, and replacing the tiles around the brackets. It is slower, more labor-intensive, and requires installers who actually know how to handle tile without turning a walkway of cracked pieces into a leak path. We have repaired more than a few tile roofs where a less experienced solar installer broke tiles during installation and sealed the cracks with caulk instead of replacing them. Caulk is not a roofing repair. It is a time bomb.
Weight is also a factor. Concrete tile weighs 9 to 12 pounds per square foot. Clay tile runs 8 to 15 pounds. Solar panels add another 2.5 to 3 pounds per square foot. For older homes, the structural load needs to be verified — Honolulu's Department of Planning and Permitting[4] may require an engineering assessment if the original plans do not account for the additional load. This is especially relevant for single-wall construction homes from the 1950s and 1960s that are all over Kaimuki and Manoa.
If you already have a tile roof in good condition, solar works great on it — just make sure your installer has specific tile roof experience and uses proper tile hooks, not improvised brackets. If you are choosing a new roof and want tile aesthetics, consider a metal roof with a tile profile instead. Several manufacturers make standing seam panels with pressed tile shapes that look like traditional tile from the street but mount solar like a standard metal roof.
Flat roofs and low-slope roofs with modified bitumen (mod-bit) membrane are standard on commercial buildings and increasingly common on modern residential construction in Hawaii. You see them on a lot of the newer townhomes in Kakaako and Koa Ridge.
Solar on a flat roof uses either ballasted racking (panels on weighted frames, no roof penetrations) or mechanically attached systems that bolt through the membrane into the structural deck. Ballasted systems are gentler on the roof but heavier — the concrete ballast blocks add 3 to 5 pounds per square foot on top of the panel weight. The roof structure needs to handle that load, and Hawaii's building code requires that the system withstand sustained trade winds and potential hurricane-force gusts.
The advantage of flat roofs is tilt optimization. Because the roof itself is flat, the racking tilts panels to the ideal angle for Hawaii's latitude — roughly 20 degrees facing south. This can produce 10–15% more energy per panel than a panel mounted flush on a sloped roof that faces east or west, which is common on many Oahu tract homes with hip roofs.
Mod-bit membrane lasts 15 to 25 years in Hawaii, with single-ply TPO and PVC membranes at the higher end of that range. The same reroof timing concern applies here as with asphalt shingles — if the membrane is more than halfway through its life, replace it before installing solar. Mod-bit and TPO are relatively fast and inexpensive to replace compared to shingles, so the bundling economics are even more favorable.
AEI holds CertainTeed 5-Star contractor certification[5], which is CertainTeed's highest credentialing level for roofing professionals. This is not a participation trophy. The 5-Star program requires documented training, verified installation volume, and proven warranty compliance. It qualifies us to offer CertainTeed's SureStart Plus extended warranty, which covers not just materials but labor on warranty claims for up to 50 years on qualifying products.
Why does this matter for a solar installation? Because the company installing your panels should understand your roofing system at a professional level. When our crew is on your roof drilling standoff mounts into decking, they know the underlayment spec, the flashing requirements, and the manufacturer's warranty conditions for the roofing material they are penetrating. A solar-only company does not have that knowledge. They drill holes and seal them. We understand the full roofing assembly and how to maintain its warranty integrity while adding solar.
This is the same reason we recommend bundling roof replacement and solar installation into a single project when the roof is aging. One crew, one permit process, one company responsible for the entire system from decking to panels. No finger-pointing between a roofer and a solar installer when something leaks.
The decision is straightforward once you know the age and condition of your existing roof.
Bundle them together if your roof is more than 12 years old (asphalt shingle) or more than 20 years old (tile or flat membrane), if you are seeing any signs of wear — cracked or missing shingles, granules in the gutters, visible rust on metal flashing, or water stains on interior ceilings, or if you want to upgrade from shingles to metal specifically to optimize the solar installation. Bundling saves $2,000 to $5,000 compared to doing them separately because you eliminate the second mobilization, second permit, and the future cost of removing and reinstalling panels for a reroof.
Do them separately if your roof is less than 5 years old and in sound condition, if you have a metal or tile roof with 20+ years of remaining life, or if your budget requires phasing the projects. In these cases, solar goes on the existing roof without concern.
The gray zone is roofs between 5 and 12 years old. This is where a professional inspection earns its value. We will walk the roof, check the decking from the attic side, assess the flashing and penetrations, and give you an honest remaining-life estimate. We do this as part of every solar consultation because putting panels on a roof that needs replacement in five years is a disservice to the homeowner.
After three decades of roofing and solar work on Oahu, here is what we tell every homeowner who asks. If you are doing a new roof and solar together, go with standing seam metal in aluminum or Galvalume. The upfront premium pays for itself in longevity, zero-penetration mounting, lower cooling costs, and avoided reroof hassle. If your existing roof is in good shape with 15+ years of life left, install solar on whatever you have — asphalt, tile, or flat — and do not overthink it. The important thing is getting panels up and generating savings against HECO rates that are north of $0.40 per kilowatt-hour[6]. If your roof is aging and you are weighing whether to replace it first, call us. We will evaluate both the roof and the solar opportunity together and give you a single quote that covers everything.
The worst decision is installing solar on a failing roof. The second worst is paying two different companies to do work that should be one coordinated project.
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