Annual Residential Roof Age Index Report
How old are residential roofs in Western North Carolina, the Charlotte region and East Tennessee, and where do older roofs meet frequent hail?
- Published September 2026
An estimated 410,000 owner-occupied single-family homes across Western North Carolina, the Charlotte region and the Knoxville area have a roof that is 20 years old or older. Replacing those roofs at the regional median cost of a roof job would total an estimated $4.3 billion.
The Roof Age Index estimates residential roof age for 44 counties and more than 300 ZIP codes using U.S. Census Bureau housing surveys, and pairs it with NOAA radar hail records and climate normals. All of the data is free to download with citation. Note: Every roof-age figure on this page is shown with its estimated range. How the estimates are made.
Key findings
- About 4 in 10 homes in the Knoxville area and Western North Carolina, and 1 in 3 in the Charlotte region, have an estimated roof age of 20 years or more.
- The Charlotte region has the youngest roofs but the most older roofs: an estimated 200,000 homes and $2.2 billion in replacement value, because its housing stock is more than twice the size of either other market’s.
- Hail is most frequent around Charlotte. NOAA radar detected hail 1 inch or larger an average of 1.7 days a year there, against 1.4 in the Knoxville area and 1.0 in Western North Carolina.
- The Knoxville area is the only market where an older roof stock and above-average hail coincide. 63% of its homes are in counties rated Highest or Elevated on the Composite Risk Index.
- Climate stress runs in opposite directions. The Charlotte region averages 49 days a year at 90°F or hotter; Western North Carolina averages 97 freeze-thaw days.
- Western North Carolina’s estimates allow for Hurricane Helene. The federal surveys predate the storm, so the low end of every range there is lowered to account for roofs replaced afterward.
Estimated roof age by market
Market | Estimated share of homes with a roof 20+ years old | Estimated range | Estimated median roof age | Owner-occupied single-family homes (Census estimate) | Estimated homes with a roof 20+ years old | Estimated replacement value |
|---|---|---|---|---|---|---|
Knoxville & East Tennessee | 39% | 31–48% | 13–19 years | 255,000 | 99,000 | $880 million |
Western North Carolina | 39% | 23–43% | 13–17 years | 282,000 | 110,000 | $1.2 billion |
Charlotte region | 33% | 27–37% | 12–15 years | 612,000 | 200,000 | $2.2 billion |
Estimates from the Benton Roofing Roof Age Index, modeled from U.S. Census Bureau American Community Survey 2020–2024 and American Housing Survey 2017–2023 data. Owner-occupied single-family detached homes, as of 2026. Estimates, not measurements; ranges combine survey uncertainty and model choice. Replacement values use the regional median roof-job cost and are conservative. Western North Carolina’s estimated range also accounts for older roofs that Hurricane Helene repairs may have replaced.
Twenty years is the life expectancy that a 2007 National Association of Home Builders and Bank of America Home Equity study lists for asphalt roofing. An older roof doesn’t necessarily need replacing.
How often hail hits
Market | Radar hail days/yr (1 in+) | Radar hail days/yr (1.75 in+) | Hail Exposure Index |
|---|---|---|---|
Charlotte region | 1.7 | 0.42 | 132 |
Knoxville & East Tennessee | 1.4 | 0.29 | 108 |
Western North Carolina | 1.0 | 0.19 | 77 |
Sources: NOAA NCEI Severe Weather Data Inventory (NEXRAD Level-III hail detections) and NOAA NCEI Storm Events Database, 2000–2025. Radar hail days = average days a year radar detected hail 1 inch or larger at a typical location in the county. Index: three-market average = 100.
Radar detects hail whether or not anyone is there to report it. Storm reports, by contrast, track where people live. Why we use radar.
Heat and freeze-thaw
Market | Days a year at 90°F or hotter | Heat index (three-market average = 100) | Freeze-thaw days a year | Freeze-thaw index (three-market average = 100) |
|---|---|---|---|---|
Charlotte region | 49 | 130 | 66 | 86 |
Knoxville & East Tennessee | 35 | 92 | 79 | 103 |
Western North Carolina | 16 | 43 | 97 | 128 |
Market figures average the homes in each market. Sunlight differs by less than 3% across the three markets. Three-market average: 38 days at 90°F or hotter, 76 freeze-thaw days. Source: NOAA NCEI U.S. Climate Normals 1991–2020. County figures are the median of NOAA stations in the county within 200 m of the elevation where most residents live, or the nearest representative station where a county has none. Local microclimates vary; single-station counties are less certain. Freeze-thaw days: the low reaches 32°F or colder and the high rises above 32°F. A descriptive climate comparison, not an estimate of roof life. Benton Roofing Roof Age Index.
Where older roofs meet frequent hail
The Composite Risk Index ranks the 44 counties on both estimated roof age and radar hail frequency, then retests every ranking under 12 sets of assumptions. A county’s tier is the one it lands in most often. Counties without a consistent result aren’t assigned one. Tiers compare these counties with each other and are not a forecast of damage.
Market | Share of owner-occupied single-family homes in Highest or Elevated counties |
|---|---|
Knoxville & East Tennessee | 63% |
Western North Carolina | 21% |
Charlotte region | 1% |
Market | Highest | Elevated | Moderate | Lower | No consistent tier |
|---|---|---|---|---|---|
Western North Carolina | 1 (Burke) | 2 (Caldwell, Wilkes) | 3 | 11 | 6 |
Charlotte region | 1 (Anson) | 0 (—) | 8 | 1 | 1 |
Knoxville & East Tennessee | 2 (Anderson, Roane) | 2 (Campbell, Knox) | 0 | 2 | 4 |
Composite Risk Index, Benton Roofing Roof Age Index. Tiers combine where roofs are oldest (estimated share of owner-occupied single-family homes with a roof 20+ years old) and where hail is most frequent (NOAA radar hail days, 2000–2025), ranked in thirds across the 44 counties in Benton Roofing’s three markets. Each county was tested under 12 sets of assumptions; the tier shown is the one it lands in most often, with how many of the 12 agree. Counties without a consistent result are not assigned a tier. Tiers are relative to these 44 counties, not a forecast of damage. Heat and freeze-thaw days (NOAA 1991–2020 normals) are shown for context and are not part of the tier.
Hail frequency varies more than fourfold across the 44 counties, while estimated roof age varies far less, so hail drives most of the differences between counties:
Explore each market
- Knoxville & East Tennessee: an estimated 39% of homes have a roof 20+ years old, and 63% of homes are in Highest or Elevated counties.
- Western North Carolina: an estimated 39% (range 23–43% after allowing for Helene); the highest combined risk is in the foothills.
- Charlotte region: an estimated 33%, but the most older roofs (200,000 homes) and the most hail.
Each market page has every county and the ZIP codes with the most older roofs.
Download the data
File | Contents |
|---|---|
Estimated roof age by market | |
Estimated roof age by county, with ranges and the Helene adjustment | |
Estimated roof age by ZIP Code Tabulation Area | |
Results at each age threshold, replacement rate and aging model | |
Radar hail days and storm report counts by county | |
Days at 90°F or hotter and freeze-thaw days by county, with station details | |
Composite Risk Index tiers, with the result under each assumption set | |
What every column means |
Use and cite this data
The data, tables and charts are free to download and reuse under the Creative Commons Attribution 4.0 International License (CC BY 4.0), including for commercial use. Please credit Benton Roofing, Roof Age Index 2026, link to https://bentonroofing.com/roof-age-index/, and note any changes you made. The Benton Roofing name and logo are not covered by the license.
Reporters: for interviews, images or questions about the method, email contact@bentonroofinginc.com.
Found an error? Email contact@bentonroofinginc.com. Corrections are noted on the methodology page with their date.
About the study
The Roof Age Index applies the annual roof replacement rates homeowners reported in the Census Bureau’s American Housing Survey (2017–2023) to the age of each county’s and ZIP code’s housing stock from the American Community Survey (2020–2024). Hail exposure comes from NOAA NEXRAD radar detections, 2000–2025; heat and freeze-thaw days from NOAA’s 1991–2020 Climate Normals. The study covers owner-occupied single-family detached homes only.
It does not forecast damage, insurance claims or roof failures; does not claim trends; and does not estimate the age of any individual roof. Read the full methodology.
The Roof Age Index is published by Benton Roofing, a roofing contractor headquartered in Flat Rock, North Carolina, with offices in Charlotte and Knoxville. It will be updated annually as new Census Bureau and NOAA data are released.