By The Roofing Brief Team | Last reviewed: October 2026
20 year shingles are 3-tab asphalt strip shingles sold with a 20-year limited warranty, such as Owens Corning Classic, IKO Marathon 20 and CertainTeed CT 20. In 2026 the five large North American shingle makers no longer list a 20-year term in their current warranty tables, so a “20 year” roof is usually an older roof. Expect about 20 years of service, a 60 mph wind warranty, and a hard time matching the shingles for repairs.
Most people who search this term are not shopping for a new 20-year roof. They own one, are buying a house with one, or have a storm claim on one. This page focuses on those owners: how to identify what is on the roof, why repairs often fail to match, what is left of the old warranty, and when replacement makes more sense. If you are comparing new entry-level shingles, our guide to 25 year shingles covers the current 3-tab warranties line by line.
Key numbers at a glance
These are the figures most owners of a 20-year shingle roof need first. Each comes from a manufacturer document, a public inspection chart, a statute or dated retail listings, and real outcomes vary with climate, ventilation, installation quality and the warranty edition that applied to your purchase or installation date.
| Figure | Value | Source |
|---|---|---|
| Typical life expectancy of 3-tab asphalt shingles | About 20 years (architectural: about 30) | InterNACHI Standard Estimated Life Expectancy Chart for Homes |
| Full-coverage period on legacy 20-year lines | 3 years (Owens Corning Classic, IKO Marathon 20, CertainTeed CT 20) | OC warranty Pub. 16-RR-24767-D (2002); IKO Marathon 20 sell sheet (2007); CertainTeed XT 25 / CT 20 brochure (2015) |
| Wind warranty on legacy 20-year lines | 60 mph | Same three documents |
| Shortest fixed term in current major-brand warranty tables | 25 years (no 20-year term listed) | GAF, Owens Corning, CertainTeed, IKO and TAMKO warranties, 2025 to 2026 editions |
| Retail price, entry 3-tab bundle | About $30 to $45 (3 bundles per square) | Google Shopping listings seen October 18, 2026 (table below) |
| Installed cost to replace, 3-tab vs architectural | $4 to $6 vs $5 to $8 per sq ft | The Roofing Brief 2026 Roofing Cost Report |
What are 20 year shingles?
A 20 year shingle is an asphalt shingle sold with a 20-year limited warranty against manufacturing defects. The label was the bottom warranty tier, almost always on a single-layer 3-tab strip with a fiberglass mat and ceramic-coated granules. The number names a warranty term, not a measured service life, and the warranty pays only for defects, not for storm damage or normal wear.
Three documented examples show what the tier looked like. Owens Corning’s December 2002 Limited Warranty on Roofing Shingles (Pub. No. 16-RR-24767-D) lists Classic at 20 years with a 60 mph wind rating, and states that the TRU PROtection full-coverage period “is three (3) years for 20-year warranted shingles and five (5) years for all other shingles.” IKO’s Marathon 20 sell sheet (January 2007) lists a limited 20-year warranty, 3-year Iron Clad protection and 60 mph wind coverage. A 2015 CertainTeed brochure lists CT 20 at about 195 pounds per square with a 20-year warranty, 3-year SureStart protection and a 5-year, 60 mph wind warranty.
| Legacy 20-year line | Maker | Size and exposure | Full-coverage period | Wind warranty | Source document |
|---|---|---|---|---|---|
| Classic | Owens Corning | 12 x 36 in, 5 in exposure, 80 shingles per square | 3 years TRU PROtection | 60 mph | OC warranty Pub. 16-RR-24767-D (Dec 2002); OC guide spec Section 07 31 13 (2013) |
| Marathon 20 | IKO | 13-1/4 x 39-3/8 in (metric), 5-5/8 in exposure, 32.3 sq ft per bundle | 3 years Iron Clad | 60 mph | IKO Marathon 20 sell sheet (01/07); Marathon series sell sheet MR9L023 (11/12) |
| CT 20 | CertainTeed | About 195 lb per square (size not stated in brochure) | 3 years SureStart | 60 mph, 5 years | CertainTeed XT 25 / CT 20 brochure (2015) |
Note the size column. A 20-year roof can be “English” size (12 x 36 inches) or “metric” size (about 13-1/4 x 39-3/8 inches) depending on the brand and plant, and that difference decides whether a repair can match. The types of asphalt shingles guide explains how 3-tab differs from laminated and designer grades.
Are 20 year shingles still made in 2026?
Not by the five major brands as a current warranty tier. The 2025 and 2026 residential warranties from GAF, Owens Corning, CertainTeed, IKO and TAMKO list 25 years as their shortest fixed term, on one 3-tab line each, and Limited Lifetime on their laminated lines. A product still labeled “20 year” in 2026 is most likely leftover stock or an old listing.
Owens Corning Classic shows how this looks in practice. Owens Corning’s January 2026 warranty (Pub. No. 10023873-H) lists Woodcrest, Woodmoor, Duration, Oakridge and Supreme, with Supreme as the only fixed-term shingle at 25 years. Classic is not in that table. Lowe’s still has indexed “Owens Corning 20-Year Classic” product pages, and a Google Shopping listing from one online seller showed Classic Onyx Black at $44.86 a bundle on October 18, 2026, so remaining stock may surface. A listing is not proof of stock, so ask the seller which warranty document ships with the bundle.
The nearest current products are the 25-year 3-tab lines: GAF Royal Sovereign, Owens Corning Supreme, CertainTeed XT 25, IKO Marathon Plus AR and TAMKO Elite Glass-Seal. Availability is narrowing there too. In a January 15, 2025 customer letter, Owens Corning said it was discontinuing Supreme and Supreme Metric in several plant service areas, which the 3-tab shingles guide lists.
How long do 20 year shingles really last?
20 year shingles typically last about 20 years, and less on hot, sun-facing or poorly ventilated roofs. InterNACHI’s Standard Estimated Life Expectancy Chart for Homes lists 3-tab asphalt shingles at 20 years and architectural asphalt at 30, and notes that the life of a roof depends on local weather, design, material quality and maintenance. The warranty term and the service life are separate numbers that happen to be close for this tier.
Manufacturers say plainly that the warranty term is not a prediction. TAMKO’s Elite Glass-Seal data sheet (rev. 01/19/2026) states that shingles “begin to age as soon as they are exposed to nature” and that “it is difficult to predict how long shingles will last.” For a roof that is already 18 to 22 years old, the signs that matter more than the label are granule loss down to the mat, curled or cracked tabs, missing tabs after wind, and stains on the attic deck. Our asphalt shingle roof lifespan guide walks through those signs by roof face.
The wind warranty is part of the story. A 60 mph blow-off warranty sits only 2 mph above the 58 mph wind speed the National Weather Service uses to define a severe thunderstorm, so a single strong storm can test a 20-year roof’s limit. On Owens Corning Classic (2002 warranty) and CertainTeed CT 20, that 60 mph blow-off coverage ran for 5 years, not the whole 20.
How can you tell the difference between 20 and 30-year shingles?
The quickest field test is layers. A 20-year shingle is a flat, single-layer 3-tab strip with three equal tabs; most shingles sold as 30-year in the 2000s were laminated (two-layer) architectural shingles with a staggered, shadowed edge. A 20-year and a 25-year 3-tab look almost identical, so separating those two takes paperwork, weight or the exact product name.
The label alone can mislead. GAF’s current Shingle and Accessory Limited Warranty (RESWT160L) still lists Marquis WeatherMax, a 3-tab shingle, at 30 years, so “30 year” has not always meant laminated. Use the clues below together.
| Clue | Typical 20-year shingle | Typical 30-year shingle | Source or basis |
|---|---|---|---|
| Layers at the bottom edge | One flat layer, three equal tabs | Usually two laminated layers, irregular tabs | Product construction described in maker data sheets |
| Weight per square | About 195 lb (CertainTeed CT 20) | Heavier; CertainTeed lists Landmark at 211 to 225 lb | CertainTeed 2015 brochure; Landmark data sheet |
| Full-coverage period on the warranty | 3 years (Classic, Marathon 20, CT 20) | 5 years on OC’s other 2002 lines, including 30-year | OC warranty Pub. 16-RR-24767-D |
| Wind warranty | 60 mph | 70 to 80 mph on OC’s 2002 30-year lines | OC warranty Pub. 16-RR-24767-D |
| Paperwork | Invoice or wrapper names Classic, Marathon 20, CT 20 or similar | Names a 30-year line | Your purchase and warranty records |
How to identify the shingles on your roof
You can usually pin down the product in under an hour with records and a tape measure. The goal is the exact brand, line, size and color, because a repair, a warranty claim and an insurance estimate all depend on them. Work through these steps in order and stop once you have the product name.
- Check your records. Look for the roofing contract, invoice, permit card or warranty registration. Many name the shingle line and color outright.
- Look for leftover bundles. Spare bundles in a garage, shed or attic carry the brand, line, color name and plant on the wrapper.
- Measure the exposure from a safe spot, such as a ladder at the eave. About 5 inches suggests English size (Owens Corning Classic and Supreme, CertainTeed XT 25, GAF Royal Sovereign English), 5-1/8 inches matches TAMKO Elite Glass-Seal, and about 5-5/8 inches suggests metric size (IKO Marathon lines, metric Royal Sovereign or Supreme).
- Measure a tab. A 36-inch strip gives 12-inch tabs; a 39-3/8-inch metric strip gives tabs of about 13-1/8 inches.
- Count the layers at the bottom edge. One layer means a 3-tab family product; two bonded layers means a laminated shingle.
- Ask a roofer to pull a loose or damaged shingle. Some makers print identifying marks on the back or on the release tape, which a supplier can sometimes trace.
- Photograph everything in daylight, including a close-up of the granules next to a tape measure, for your contractor or adjuster.
If you are not sure the roof is even asphalt, start with what kind of roof do I have. Stay off the roof surface yourself; walking an old 3-tab roof can break brittle tabs and is a fall risk.
Repairing a 20-year shingle roof: the size and color match problem
A patch on a 20-year shingle roof often cannot match. The original line is gone, current 3-tab lines come in different sizes, and 15 to 20 years of sun change the color of the old shingles. Size is the hard limit: a shingle with a different exposure will not line up course for course with the old rows, so the patch shows from the street.
The current 3-tab lines below are what a roofer can buy today. Check the exposure against what you measured on your roof.
| Current 3-tab line | Warranty | Size | Exposure | Source |
|---|---|---|---|---|
| Owens Corning Supreme | 25 years | 12 x 36 in (English); 13-1/4 x 39-3/8 in (Metric) | 5 in; 5-5/8 in metric | OC guide spec Section 07 31 13; OC warranty Pub. 10023873-H (Jan 2026) |
| GAF Royal Sovereign | 25 years | 12 x 36 in (English); 13-1/4 x 39-3/8 in (Metric, sold in the West per GAF) | 5 in; 5-5/8 in metric | ICC-ES ESR-1475; GAF Royal Sovereign product information sheet |
| CertainTeed XT 25 | 25 years | 12 x 36 in (“English” dimensions only) | 5 in | CertainTeed XT 25 technical data sheet |
| TAMKO Elite Glass-Seal | 300 months | 12-1/4 x 36 in | 5-1/8 in | TAMKO data sheet, Joplin plant (rev. 01/19/2026) |
| IKO Marathon Plus AR | 25 years | 39-3/8 x 13-1/4 in | 5-5/8 in | IKO product page, Marathon Plus AR (October 2026) |
The arithmetic below shows why size matters. It compares rows of an English roof at 5-inch exposure with replacement shingles at other exposures. Roofing Brief arithmetic from the published exposures; real roofs add field variation.
| Courses up the slope | English roof (5 in) | TAMKO Elite Glass-Seal (5-1/8 in) | Metric shingle (5-5/8 in) | Metric drift vs English |
|---|---|---|---|---|
| 1 | 5 in | 5-1/8 in | 5-5/8 in | 5/8 in |
| 4 | 20 in | 20-1/2 in | 22-1/2 in | 2-1/2 in |
| 8 | 40 in | 41 in | 45 in | 5 in (a full course) |
| 16 | 80 in | 82 in | 90 in | 10 in (two courses) |
A small patch of a few tabs can sometimes be finished with salvaged shingles from a hidden area, such as a rear dormer or garage roof, if a roofer can remove them without damage. Where the size differs, the cleanest result is usually to replace a whole roof plane bounded by a ridge, hip, valley or rake, so no course has to tie old shingles to new ones. For individual missing tabs, see what to do about missing shingles.
What happens if insurers can’t match discontinued 20-year shingles?
It depends on your policy and your state. The NAIC’s Unfair Property/Casualty Claims Settlement Practices Model Regulation (Model 902, Section 9) says that when replaced items “do not match in quality, color or size, the insurer shall replace all items in the area so as to conform to a reasonably uniform appearance.” That is a model rule; states adopt their own versions, or none, and policies can contain their own terms.
Florida is one example with a statute. Florida Statutes section 626.9744(2) says that when replaced items do not match in quality, color or size, “the insurer shall make reasonable repairs or replacement of items in adjoining areas,” and lets the insurer weigh cost, the uniformity achievable, the remaining useful life of the undamaged portion and other factors. The section opens with “Unless otherwise provided by the policy,” so the policy wording still governs. If you file a claim on a roof with discontinued 20-year shingles, give the adjuster the product name, the measured exposure and photos, and ask in writing how matching will be handled. Our hail damage roof insurance claim guide covers the claim steps.
| Rule | What it says | Where it applies | Source |
|---|---|---|---|
| NAIC Model 902, Section 9.B(2) | Replace all items in the area for a reasonably uniform appearance when replacements do not match in quality, color or size | A model; applies only where a state adopted similar language | NAIC Model Laws, Regulations and Guidelines (July 1997 printing) |
| Fla. Stat. 626.9744(2) | Insurer must make reasonable repairs or replacement in adjoining areas; may weigh cost, uniformity, remaining life | Florida homeowner policies with repair or replacement cost settlement, unless the policy provides otherwise | 2026 Florida Statutes, leg.state.fl.us |
| Fla. Stat. 627.7011(5) | No refusal or nonrenewal solely for roof age under 15 years; at 15 years or more, homeowner may get an inspection, and 5 or more years of remaining life bars refusal solely for age | Florida homeowner policies issued or renewed on or after July 1, 2022 | 2026 Florida Statutes, leg.state.fl.us |
What’s left of a 20-year shingle warranty?
On a roof installed 15 to 20 years ago, very little. Legacy 20-year warranties paid full coverage only for the first 3 years on the three lines documented above, then a shrinking share of material cost with no labor, and they excluded hail and wind above the rated speed. By year 20 the prorated payment reaches zero.
The worked example uses the Owens Corning 2002 warranty terms, which prorate by months of use: after the 3-year TRU PROtection period, the payment is reduced in proportion to the months used. Assumptions (Roofing Brief estimate): a 20-square roof, a manufacturing defect affecting the whole roof, and $2,400 of replacement shingle material at $120 per square, near the middle of the October 2026 listings below. Your own warranty edition governs, so check the document in effect when your shingles were installed.
| Claim timing | Coverage under OC 2002 terms (240-month warranty) | Share paid | Payment on $2,400 of shingles |
|---|---|---|---|
| Month 30 (year 2.5) | TRU PROtection: material and labor to repair, replace or recover | 100 percent plus labor | $2,400 plus labor |
| Month 60 (year 5) | Prorated material only: 180/240 | 75 percent | $1,800, no labor |
| Month 120 (year 10) | Prorated material only: 120/240 | 50 percent | $1,200, no labor |
| Month 180 (year 15) | Prorated material only: 60/240 | 25 percent | $600, no labor |
| Month 216 (year 18) | Prorated material only: 24/240 | 10 percent | $240, no labor |
| Month 240 (year 20) | Warranty term ends | 0 percent | $0 |
For scale, the same 20-square roof costs $8,000 to $12,000 to replace with 3-tab at the cost report’s $4 to $6 per square foot. A year-15 defect payment of $600 covers roughly 5 to 8 percent of that. Storm damage is an insurance question, not a warranty question, at any age.
How much do 20 year roof shingles cost?
Entry-level 3-tab shingles, the class that replaced the 20-year tier, listed at about $30 to $45 per bundle in Google Shopping results on October 18, 2026, or roughly $90 to $135 per square of material. Installed with tear-off and accessories, the site’s 2026 Roofing Cost Report puts 3-tab at $4 to $6 per square foot. Leftover 20-year stock, where it appears, was not cheaper.
| Product | Type | Listed price per bundle | Seller (Google Shopping, Oct 18, 2026) |
|---|---|---|---|
| Owens Corning Classic (Onyx Black) | Legacy 20-year 3-tab | $44.86 | Arbor |
| Owens Corning Supreme | 25-year 3-tab | $30.79 to $32.00 | Matt’s Building Materials; ASO Roofing Supply |
| TAMKO Elite Glass-Seal | 25-year 3-tab | $30.00 | ASO Roofing Supply |
| GAF Royal Sovereign | 25-year 3-tab | $41.47 | Home Depot |
| CertainTeed XT 25 | 25-year 3-tab | $41.48 | Lowe’s |
| Owens Corning Oakridge (comparison) | Lifetime architectural | $33.00 | All Roofing Supply |
| CertainTeed Landmark (comparison) | Lifetime architectural | $43.47 | Lowe’s |
| GAF Timberline HDZ (comparison) | Lifetime architectural | $45.47 | Home Depot |
The shelf gap between 3-tab and architectural is small and sometimes reversed. At Home Depot that day, Royal Sovereign ($41.47) and Timberline HDZ ($45.47) were $4 apart per bundle, which is $12 per square or $240 on a 20-square roof. One supplier listed Oakridge architectural below some 3-tab listings. Prices vary by region, color and seller, and contractors usually buy by the pallet. Our shingle bundle prices report tracks supply-house numbers.
What it costs to replace a 20-year shingle roof
Replacing a 20-square (2,000 sq ft of roof surface) 20-year shingle roof costs about $8,000 to $12,000 with 3-tab or $10,000 to $16,000 with architectural shingles, using the site’s 2026 Roofing Cost Report ranges. Spread over InterNACHI’s life expectancies, architectural often costs the same or less per year, which is why few owners replace like for like.
| Line item (Roofing Brief estimate) | 3-tab replacement | Architectural replacement |
|---|---|---|
| Installed cost per sq ft (2026 Roofing Cost Report) | $4 to $6 | $5 to $8 |
| Roof surface | 2,000 sq ft (20 squares) | 2,000 sq ft (20 squares) |
| Installed total | $8,000 to $12,000 | $10,000 to $16,000 |
| Life expectancy (InterNACHI chart) | About 20 years | About 30 years |
| Cost per year of expected life | $400 to $600 | About $333 to $533 |
| Material share at Oct 18, 2026 listings ($90 to $136 per square) | About $1,800 to $2,700 | About $1,980 to $2,730 |
The material rows show that most of the bill is labor, tear-off, underlayment, flashing and disposal, which do not change much with the shingle grade. Roof size in squares includes slope, so measure or get the roofer’s square count before comparing quotes. The 3-tab vs architectural shingles comparison covers look, wind and resale in more depth.
Can you sell a house with a 20 year old roof?
Yes. No general rule bars selling a house with a 20-year-old roof, but the buyer’s loan and insurance can bring the roof into the deal. For FHA-insured loans, HUD Handbook 4000.1 tells the appraiser to notify the lender if the roof covering does not have a remaining physical life of at least two years, and HUD has been revising those property requirements, so the lender should confirm the current text.
Insurance is the second hurdle. In Florida, section 627.7011(5) protects roofs under 15 years old from refusal solely for age; a 20-year-old roof falls in the “at least 15 years” group, where the homeowner may have an authorized inspector show 5 or more years of remaining useful life. Other states and insurers set their own roof-age rules, and our report on insurance non-renewal and roof age covers those. Disclosure duties also vary by state; the roof age at home sale report summarizes them.
Sellers usually take one of three paths: replace before listing, offer a credit sized to a written replacement quote, or sell as is with a recent roof inspection report. Buyers looking at a house with a 20-year shingle roof can budget the replacement figures above and ask for the seller’s invoice and any warranty paperwork.
Repair, match or replace: which fits your 20-year roof?
The right call depends on the roof’s condition, whether a size match exists, and how long you will own the house. A sound roof with a small, matchable repair can run several more years; a roof near 20 years with storm damage and no match usually points to a full replacement, often through an insurance claim if the damage is covered.
| If your situation is | Then consider | Why |
|---|---|---|
| A few missing tabs, roof otherwise sound, matching size in stock | Spot repair with the same-size 3-tab | Courses line up; color difference fades over time but may stay visible |
| Small repair, no same-size shingle available | Salvaged shingles from a hidden area, or replace the whole affected roof plane | Different exposures drift 5/8 in per course (metric vs English) |
| Storm damage on a discontinued 20-year roof | File the claim with product name, exposure and photos; ask how matching is handled | State matching rules and policy wording decide the scope |
| Roof at 18 to 22 years, granule loss or curling, no leaks yet | Plan replacement within a few years; get two written quotes | InterNACHI puts 3-tab life at about 20 years; legacy warranty is near zero |
| Selling soon with an FHA buyer likely | Get a roof inspection before listing | Appraiser must flag a roof with under two years of remaining life |
| Shed, detached garage or short hold | Like-for-like 25-year 3-tab is reasonable | Small area and low stakes; the per-year math matters less |
| Long-term home in a windy or hail-prone area | Replace with a laminated lifetime-warranty shingle | Longer expected life and higher wind ratings; see the 40 year shingles guide for how upper tiers were renamed |
Frequently asked questions
How long do 20 year shingles really last?
20 year shingles usually last about 20 years. InterNACHI’s Standard Estimated Life Expectancy Chart for Homes lists 3-tab asphalt shingles at 20 years and architectural shingles at 30. Hot climates, sun-facing slopes, weak attic ventilation and poor installation can shorten that. The 20-year figure is the length of a prorated defect warranty, and makers such as TAMKO state that it is difficult to predict how long shingles will last.
How can you tell the difference between 20 and 30-year shingles?
Look at the bottom edge. A 20-year shingle is a flat, single-layer 3-tab strip with three equal tabs, while most shingles sold as 30-year were laminated architectural shingles with two layers and irregular tabs. A 20-year 3-tab is also lighter, about 195 pounds per square for CertainTeed CT 20. The surest answer is the product name on your invoice, warranty or a leftover bundle wrapper.
Can you sell a house with a 20 year old roof?
Yes. No general rule bars selling a house with a 20-year-old roof, but the buyer’s lender and insurer may push for repair or replacement. For FHA loans, HUD Handbook 4000.1 tells the appraiser to flag a roof with less than two years of remaining physical life. Some insurers restrict older roofs, and state disclosure rules apply, so many sellers get a roof inspection before listing.
How much do 20 year roof shingles cost?
Entry-level 3-tab shingles, the class that replaced the 20-year tier, listed at about $30 to $45 per bundle on October 18, 2026, or roughly $90 to $135 per square of material. Installed, The Roofing Brief’s 2026 Roofing Cost Report puts 3-tab at $4 to $6 per square foot, about $8,000 to $12,000 for 2,000 square feet of roof. Prices vary by region and seller.
Are 20 year shingles still made?
Not as a current tier from the major brands. The 2025 and 2026 warranties from GAF, Owens Corning, CertainTeed, IKO and TAMKO list 25 years as their shortest fixed term. Owens Corning Classic, a well-known 20-year line, is missing from Owens Corning’s January 2026 warranty table, though old retail listings still appear online. Treat any 20-year listing as leftover stock and confirm the warranty that ships with it.
Should I buy a house with a 20-year-old roof?
You can, but budget for a replacement soon. A 3-tab roof at 20 years is at the end of the life InterNACHI lists, and any legacy 20-year warranty has run out. Ask for the installation invoice, get a roof inspection, and price a replacement before you finalize your offer. Your lender and insurer may also ask about the roof’s remaining life.
Will insurance replace my whole roof if my 20-year shingles are discontinued?
Sometimes, depending on your policy and state. The NAIC model claims regulation says insurers should replace items in the area when replacements do not match in quality, color or size, and Florida law requires reasonable repairs or replacement in adjoining areas. Not every state has a matching rule, and policy wording can limit it, so ask your insurer in writing how matching will be handled.
Sources
- Owens Corning, Limited Warranty on Roofing Shingles with TRU PROtection Coverage, Pub. No. 16-RR-24767-D (December 2002).
- Owens Corning, residential shingle limited warranty, Pub. No. 24762-D (February 2009), lists Classic at 20 years.
- Owens Corning, Standard Product Limited Lifetime Warranty on Roofing Shingles and Components, Pub. No. 10023873-H (January 2026).
- Owens Corning, guide specification Section 07 31 13, Fiberglass-Based Asphalt Shingles (2013), Classic and Supreme dimensions.
- IKO, Marathon 20 sell sheet (01/07, MR4L313); Marathon Ultra AR, 25 AR, 25 and 20 sell sheet (11/12, MR9L023); Marathon Plus AR product page, iko.com (October 2026).
- CertainTeed, XT 25 and CT 20 Traditional Shingles brochure (2015); XT 25 Shingles Technical Data Sheet.
- GAF, Royal Sovereign Shingles product information sheet (metric); ICC-ES Evaluation Report ESR-1475 (GAF asphalt shingles).
- TAMKO, Elite Glass-Seal 3-Tab Product Data, Joplin, MO (rev. 01/19/2026).
- InterNACHI, Standard Estimated Life Expectancy Chart for Homes.
- NAIC, Unfair Property/Casualty Claims Settlement Practices Model Regulation (Model 902), Section 9.
- Florida Statutes 626.9744 and 627.7011(5), 2026 edition, leg.state.fl.us.
- U.S. Department of Housing and Urban Development, Handbook 4000.1, roof covering requirement.
- National Weather Service, severe thunderstorm criteria (winds of 58 mph or greater).
- Retail listings seen through Google Shopping on October 18, 2026: Arbor, Matt’s Building Materials, ASO Roofing Supply, Home Depot, Lowe’s, All Roofing Supply.
- The Roofing Brief, 2026 Roofing Cost Report.