Metal vs. Asphalt Shingles on Long Island: Salt Air, Wind Ratings and the Warranty Fine Print (2026)
Many steel roofing warranties stop covering corrosion within 400 to 1,500 feet of salt water. Here is what the actual warranty documents say, when aluminum makes sense, and which shingle wind class and nailing pattern Long Island code and manufacturers call for.
Short answer: for most Long Island homes, architectural asphalt shingles installed with the manufacturer's high-wind nailing pattern are the best value. Metal makes more sense if you plan to stay 20+ years, but near the water the metal matters: many steel (Galvalume) roofing warranties don't cover homes within roughly 400 to 1,500 feet of salt water, while aluminum panels have coastal warranties. Before you choose, check how far you are from the ocean, a bay or a salt marsh, and read the actual warranty.
This guide quotes the coastal clauses from published metal and shingle warranties, explains aluminum vs. Galvalume vs. steel, and shows the shingle wind classes the 2025 New York residential code requires at Long Island wind speeds.
Metal vs. Asphalt at a Glance
| Factor | Architectural asphalt | Standing seam metal |
|---|---|---|
| Up-front cost | Lowest. This Old House's cost guide (updated October 2026) puts shingles at about $7 per sq ft installed, a national average | Several times asphalt. The same guide's national average for metal is about $28 per sq ft |
| Wind | Must carry the code-required class (ASTM D7158 Class G or H at most Long Island wind speeds); 130 mph and higher warranties need extra nails and matching starter strips | Panel systems are tested as assemblies; the attachment (clips, fastener spacing) must follow the manufacturer's tested pattern |
| Salt air | No distance-from-water exclusion in the GAF, Owens Corning or CertainTeed warranties, but copper algae-resistant granules can corrode aluminum gutters near the coast | Galvalume steel warranties often exclude homes within 400 to 1,500 ft of salt water; aluminum has coastal warranties that require fresh-water rinsing |
| Repairs | Easy; most roofers can replace a shingle | Needs a metal specialist and matching panels |
| Best for | Most homes, shorter ownership horizon | Long-term owners; aluminum for homes right on the water |
National averages hide big local differences. For Long Island planning ranges and what moves the price, see our roof replacement cost guide.
What Metal Roofing Warranties Say About Salt Water
Most painted steel roofing on the market is Galvalume, steel coated with a 55% aluminum-zinc alloy (ASTM A792, which the 2025 Residential Code of New York State lists at AZ50 as the minimum for that coating). It usually carries two warranties: one on the substrate (the steel won't rust through) and one on the paint (no peeling, limited fade and chalk). Both often have a salt-water clause. Here is what the published documents say:
| Warranty document | What it covers | Coastal clause (quoted) | Distance |
|---|---|---|---|
| Sheffield Metals, 50-Year Painted AZ50 Galvalume "Metal" Warranty (sample) | Steel won't perforate from corrosion | Excludes "Coastline areas with a marine exposure within the following distances" | 1,500 ft from breaking surf; 800 ft from a large bay; 400 ft from marsh |
| Metal Sales, 25-Year Galvalume AZ55 Warranty | Galvalume panels won't perforate | Excludes "areas within 1500 feet of salt water, marine atmospheres, or salt spray" | 1,500 ft |
| Union Corrugating, AZ50/AZ55 Substrate and Paint Warranty | Substrate and paint | Substrate: excludes "Areas subject to salt water marine atmospheres." Paint: excludes finish "installed within 1000 meters of a salt water or other marine environment," unless the owner documents an annual fresh-water rinse, which keeps fade and chalk coverage | Substrate: none stated. Paint: 1,000 m (about 3,280 ft) |
| Central States, Lifetime Prime Fluropon paint warranty (steel panels) | Sherwin-Williams Fluropon PVDF finish | "Warranty is not valid on a property located 1,500 or fewer feet from a salt water environment" | 1,500 ft |
| United Steel Supply, Fluropon coil warranty | Fluropon finish on steel coil | No warranty on any substrate "subjected to sea spray or installed on property located 1,500 or fewer feet from a salt-water environment" | 1,500 ft |
| MBCI Technical Bulletin 002, Saltwater and Marine Atmospheres | Guidance for its panel warranties | Says a minimum safe distance "acceptable in all situations cannot be established," then gives guidelines | Painted (Signature 200/300): 1,000 ft from any saltwater. Galvalume: 1,500 ft from surf, 800 ft from a large saltwater bay, 400 ft from saltwater marshes or canals |
| Sherwin-Williams Flurothane Coastal data sheet | A coastal coil coating | Recommended for projects "within 1,500 feet of the coastline." Its 20-year coastal warranty "Excludes failure due to substrate corrosion" | Designed for inside 1,500 ft |
| Petersen PAC-CLAD, 30-Year Warranty for Aluminum Products in a Coastal Environment | Paint on aluminum panels | Within 1,500 ft of "a seacoast, saltwater or other brackish water environment," the owner must give the roof a fresh-water rinse twice a year and keep records. "Constant or direct spraying" of salt water is excluded, and the aluminum itself is sold "AS IS" | Covered inside 1,500 ft, with rinsing |
We couldn't find a published PPG Duranar coil warranty to check, so it isn't in the table. Ask for the current document for whatever finish you're quoted.
How those distances map onto Long Island
- "Breaking surf" (1,500 ft): the ocean side of the barrier beaches, from Long Beach to Fire Island and the Hamptons, and Montauk.
- "Large bay" (800 ft): waterfront on the Great South Bay, the Peconic bays and similar open bays. Whether a manufacturer treats Long Island Sound frontage as "surf" or "bay" is its call, so ask.
- "Marsh" or "canal" (400 ft): South Shore canal neighborhoods and homes beside tidal marsh.
- Flat 1,000 ft, 1,500 ft or 1,000 m rules: no tiers at all. A house a few blocks from the bay can still fall inside them.
The sample warranties don't say how distance is measured, so get the manufacturer's written confirmation for your address before you order. Petersen, for example, says on its product considerations page that "aluminum substrates, with stainless steel clips and fasteners, must be used to qualify for the coastal warranty."
Aluminum vs. Galvalume vs. Steel Near the Bays and Ocean
- Galvanized steel (zinc-coated, G90): the minimum coating the code lists for galvanized steel roofing (ASTM A653 G90).
- Galvalume (aluminum-zinc-coated steel): the standard for painted steel panels, and a good value inland. As the table shows, its warranties are the ones most likely to exclude waterfront homes. Union's substrate warranty also excludes run-off from lead or copper and contact with wet or pressure-treated lumber, both common on older coastal houses.
- Aluminum: contains no iron, so it doesn't rust the way steel does. That's why it's the metal with coastal paint warranties, such as PAC-CLAD's, and Metal Construction News lists aluminum, stainless steel and copper as the metals "preferred for coastal environments." It costs more than steel, and coastal warranties still require rinsing and exclude contact with copper or other dissimilar metals.
- Fasteners and trim: the code accepts stainless steel fasteners on any metal roof (R905.10.4). Use stainless clips and screws near the water. The same Metal Construction News article warns that hidden clips and fasteners can corrode even when the panels look fine.
As a rule of thumb from the documents above: if you're within about 1,500 feet of open salt water, price aluminum (or confirm in writing that the steel product's warranty covers your address). Farther inland, Galvalume with a PVDF (Kynar 500 or Hylar 5000) finish is the common choice.
Shingle Warranties Near Salt Water
None of the three big shingle warranties has a distance-from-water exclusion. Near the coast, the fine print that matters is about algae and gutters:
| Warranty (2026) | Algae (black-streak) coverage | Coastal note |
|---|---|---|
| GAF Shingle & Accessory Limited Warranty (RESWT160L-0426) | StainGuard: 10 years (1 year non-prorated). StainGuard Plus: 25 years (10 non-prorated). StainGuard Plus PRO on Timberline UHDZ: 30 years (10 non-prorated). Only on shingles sold in packages bearing those logos | No salt-water clause. Fungus, mold, lichen and other algae aren't covered |
| Owens Corning Standard Product Limited Lifetime Warranty (shingles purchased after August 1, 2026) | 25 years on algae-resistant (AR) shingles, 10 non-prorated, only with Owens Corning hip and ridge caps. Otherwise 10 years, 1 non-prorated. AR is sold regionally | "In some coastal areas and/or areas with limited rainfall, copper released by algae-resistant shingles can cause excessive corrosion to aluminum gutters." Recommends vinyl gutters |
| CertainTeed Asphalt Shingle Residential Products 2026 Limited Warranty | 25 or 30 years on AR versions with CertainTeed AR hip and ridge (prorated after 10 or 15 years); 10 years without them | Warns that in "salt fog" areas copper from AR granules "can react with aluminum in gutters," and recommends vinyl or copper gutters |
Long Island's humid summers make algae-resistant shingles worth it. If you're right on the water with aluminum gutters, raise the gutter warnings with your roofer. Both manufacturers' examples describe dry or foggy coasts, but they don't exclude others.
Wind: What Long Island Code Requires
Your design wind speed
New York's 2025 Uniform Code took effect December 31, 2025, per the Department of State. Each town or village records its design wind speed in a local Table R301.2(1), so ask your building department. Three published tables:
- Town of Islip (2025 code): 130 mph ultimate design wind speed, "within a hurricane prone region," with a wind-borne debris zone "1 Mile from Coast and Fire Island."
- Village of Quogue: 130 mph (120 mph allowable-stress), wind-borne debris zone: yes.
- Village of Malverne, Nassau (2025 code): 119 mph, no wind-borne debris zone.
All three tables also mark ice-barrier underlayment as required. That means a self-adhering membrane or two cemented underlayment layers from the eave to at least 24 inches inside the exterior wall (R905.1.2).
The shingle class you need
Under R905.2.4.1, shingles must be tested to ASTM D7158, and the bundle must be labeled with the class that Table R905.2.4.1 requires for your wind speed. Shingles outside D7158's scope can use the older ASTM D3161 fan test.
| Ultimate design wind speed (up to) | ASTM D7158 class allowed | ASTM D3161 class allowed | Long Island example |
|---|---|---|---|
| 116 mph | D, G or H | A, D or F | — |
| 129 mph | G or H | A, D or F | Malverne (119 mph) |
| 142 mph | G or H | F only | Islip, Quogue (130 mph) |
| 155 mph | G or H | F only | — |
Source: 2025 RCNYS Table R905.2.4.1 (excerpt).
What the classes mean:
- ASTM D3161 is a fan test. Classes A, D and F correspond to 60, 90 and 110 mph, as Professional Roofing (NRCA) explains. "Class F" on a bundle means a 110 mph test, not a 110 mph-proof roof.
- ASTM D7158 (current edition D7158/D7158M-24a) measures sealant-strip uplift resistance. The Asphalt Roofing Manufacturers Association's March 2026 bulletin lists Class D at up to 116 mph, Class G at up to 155 mph and Class H at up to 194 mph (ultimate, 3-second gust). Older articles quoting 90/120/150 mph for D/G/H use the pre-2010 wind-speed basis.
- Waterfront caveat: D7158's standard calculations assume Exposure B or C and a roof under 60 feet. A house facing open water may be Exposure D, which the code footnote says needs additional calculations. ARMA's table shows such sites often need a higher class than the same house inland.
Manufacturer high-wind nailing
The code requires the manufacturer's fastener count, and never fewer than four nails per strip shingle (R905.2.6). The nails must be roofing nails with at least a 12-gauge shank and a 3/8-inch head, penetrating 3/4 inch into the sheathing or all the way through it (R905.2.5). Each manufacturer's higher wind warranty also has its own conditions:
| Brand (2026 warranty) | Standard wind coverage | Higher coverage and its conditions |
|---|---|---|
| GAF | 110 mph on Lifetime shingles | 130 mph with "Special Installation": LayerLock-labeled shingles need 4 nails, and all other GAF shingles need 6 nails per shingle. Both need GAF starter strips at the eaves and rakes. 15-year wind term |
| Owens Corning | Oakridge: 110 mph with 4 nails. Duration: 130 mph | Oakridge reaches 130 mph only with 6 nails and Owens Corning starter at the eaves and rakes. Duration reaches 160 mph ("Enhanced") with Owens Corning starter, hip and ridge caps, synthetic underlayment and one more qualifying component, installed per its Enhanced Wind Application Instructions. 15-year wind period |
| CertainTeed | 110 mph | 130 mph (e.g., Grand Manor, Belmont, Highland Slate) or 160 mph (Landmark family) for the first 15 years. Requires no roof-over, CertainTeed hip and ridge caps, and CertainTeed starter at the eaves and rakes. No coverage for shingles not fastened per its instructions |
On a Long Island roof, ask for the six-nail (or LayerLock) pattern and matching starter strips at both the eaves and the rakes, and get the shingle's D7158 class in writing. Metal panels and metal shingles follow their own tested attachment schedules; the code lists ASTM D3161, FM 4474, UL 580 and UL 1897 for metal shingles (R905.4.4.1).
Snow, Ice Dams and Lifetime Cost
Snow slides off metal, so ice dams are less likely, though snow guards may be needed over doors and walkways. On asphalt, ice dams are controlled with the code-required ice barrier, attic insulation and ventilation; see our roof ventilation guide.
Over 40 years, an asphalt roof will usually need replacing at least once, while a well-installed metal roof may not. That narrows metal's cost gap if you're staying put. Some insurers discount wind- or impact-resistant roofs; ask your carrier rather than assuming.
Other Materials on Long Island
- Stone-coated steel: steel panels with a granule finish that look like shingles, shake or tile. Because they're steel, check the coastal clause in their warranty as you would for any steel product.
- Natural slate: very long-lived but heavy, so the framing has to be checked. Specialist work, mostly for historic homes.
- Synthetic slate: the slate look at a fraction of the weight and cost.
- Cedar shingles and shakes: the code requires Type 316 stainless steel fasteners within 15 miles of saltwater coastal areas (R905.7.6 and R905.8.7). That covers most, if not all, of Long Island.
- Flat sections: TPO, EPDM or modified bitumen on low slopes only.
Which Should You Choose?
| Where the house is | Usually the better fit |
|---|---|
| Oceanfront, bayfront or on a canal (inside the 400 to 1,500 ft zones) | Aluminum standing seam with stainless fasteners and a written coastal warranty, or algae-resistant architectural shingles with a high-wind install. Avoid steel unless the warranty names your address |
| Within about a mile of the coast (wind-borne debris zone in towns like Islip) | Either works. Confirm the shingle class for your town's wind speed, and check any steel warranty with a flat 1,000 m or 1,000 ft rule |
| Inland Nassau and Suffolk | Architectural asphalt for value. Galvalume with a PVDF finish if you want metal |
Questions to Ask Before You Sign
- What is the exact product, and can I see its current warranty, including the coastal clause?
- Will the manufacturer confirm in writing that my address qualifies?
- What D7158 class is the shingle, and what is my town's design wind speed?
- Are you installing the high-wind nailing pattern and the manufacturer's starter at the eaves and rakes?
- Are the fasteners and clips stainless steel? What gutters are you pairing with copper algae-resistant shingles?
Installation quality matters as much as the product. Our guide on how to choose a roofing contractor on Long Island covers what to check, and our metal roofing page explains the panel systems.
Want quotes from local roofers? Request free quotes; we'll connect you with independent contractors. Long Island Roofing Pros is a free referral service and doesn't do roofing work.