Key numbers
45 verified hail storms with stones of 1.75 inches or larger reached Denver County from 1984 to 2026 in the storm records we keep; the largest measured 4.5 inches (softball size) on July 13, 2011 (NOAA NCEI).
| Hail storms by decade, 1984 to 2026 | 1980s: 1, 1990s: 4, 2000s: 12, 2010s: 17, 2020s: 11 Source: Storm library: Denver metro hail history |
|---|---|
| Largest hail | 4.5 in. (softball), July 13, 2011 Source: NOAA NCEI |
| Costliest hail storm | $2.3 billion insured losses (2017 dollars), May 8, 2017 Source: RMIIA |
| 15 | In hail-prone states the average roof lifespan is 15 years, versus 22 years in drier western states such as Nevada, Arizona and Utah. Source: Insurance Journal (reporting Verisk), 2025 (report year) |
| About 10% | Unvented attics typically run asphalt shingles 2-3°F hotter on average, which Building Science Corporation estimates cuts shingle service life about 10%; shingle color and orientation matter two to three times more. Source: Building Science Corporation, 2006 (rev. 2013) |
| 24% | In 2023, improvement spending on U.S. homes built before 1980 was 24% higher than on homes built since 2010, and maintenance spending was 76% higher. Source: Harvard Joint Center for Housing Studies, 2023 |
A storm counts when the library lists Denver County among the areas it hit. Each hail size is the storm's largest report, which may have fallen in a neighboring county, and insured losses cover every area the storm hit.
Local building code: Denver roof code data: IRC edition, reroof permits, ice barrier
A Denver roof needs replacing when it is at the end of its life (most asphalt roofs here are 20 to 25 years old by then), when leaks keep returning in different places, or when hail or wind damage is spread across several slopes. The replacement itself is usually a one- or two-day job: tear-off to the deck, repairs to the decking, new underlayment and flashing, new roofing, cleanup, and a final city inspection. What varies most is the paperwork, because every city around Denver has its own rules for permits, layers and inspections.
Signs it is time
- Age. Asphalt shingle roofs in Denver commonly reach 20 to 25 years before replacement. Tile, slate and metal last much longer. Our article on when an asphalt roof needs replacement has the details.
- Granules in the gutters, curling or cracked shingles. The shingles are wearing out from the top down.
- Leaks that move. One leak is a repair. A new leak every season is a roof that is failing.
- Soft spots or sagging. That points to wet or damaged decking.
- Storm damage across several slopes. See Denver storm damage repair; the claim stays yours, and our photos make sure nothing gets missed in the scope.
If only one area is bad, start with Denver roof repair instead.
Tear-off rules around the metro
| Where | Can you overlay? | Notes |
|---|---|---|
| Denver | One re-cover over a single layer | Two or more layers must come off. Decking gaps over 1/2 inch must be closed. |
| Littleton | No | Full tear-off to the deck on every roof. |
| Lakewood | No | Residential roofs are removed to the deck; spaced boards must be overlaid with panel sheathing. |
| Centennial | No | All existing layers are removed to the deck. |
| Castle Rock | No | 100% tear-off, including the old underlayment. |
| Unincorporated Adams County | No | One layer of roofing maximum. |
Even where an overlay is allowed, a full tear-off is the only way to see and fix the decking.
Denver-specific steps on a replacement
- Permit before work. Every Denver replacement needs a permit, and you can look it up by address.
- Insulation check. If the roof has no insulation in the cavity and the sheathing is exposed during the re-roof, Denver’s energy code requires adding it, either above the sheathing (R-30ci) or below it (R-38 for flat roofs, R-49 for attics).
- Ventilation. Denver does not inspect venting on re-roofs, but manufacturer warranties often require proper ventilation, so it is worth checking during the inspection.
- Asbestos. Older roofing may need a certified asbestos inspection under CDPHE rules before tear-off.
- Final inspection. One- and two-family asphalt roofs get a final inspection; townhomes also get a pre-inspection.
Choosing the new roof? Our Denver residential roofing guide compares materials and wind ratings.
Gutters come off during tear-off and go back on over the new drip edge; if they are dented or undersized, replace them in the same project. See Denver gutters.
Cost and financing
See how much a roof replacement costs in Denver. Financing is available, and many storm-damaged roofs are replaced through homeowners insurance.
We are veteran-owned, family-run since 1990, an Owens Corning Platinum Preferred contractor, and have 650+ Google reviews. Call our Centennial office at (303) 209-0152 or book a free Denver roof inspection. If the roof does not need replacing yet, we will tell you.
Sources: City and County of Denver, Roofing Guide and Checklist (updated 4/11/2024); City of Littleton, Policy 24-001; City of Lakewood, Roofing and Re-roofing handout; City of Centennial; Town of Castle Rock, Re-Roof Checklist; Adams County, Residential Roofing Requirements (July 2026).
Photos From Our Projects
