An ASTM D3161 rating on a shingle bundle means the shingle passed a standard wind test, and its class letter (A, D or F) tells a building inspector which wind speeds it is approved for. Under the 2021 International Residential Code (IRC) Section R905.2.4.1, asphalt shingles must first be tested and labeled to ASTM D7158 (classes D, G or H); ASTM D3161 is the fallback for shingles outside D7158’s scope. In the Pikes Peak region, where homes are designed for 130 mph, that means D7158 Class G or H, or D3161 Class F.
The code table, in one place
Table R905.2.4.1 of the 2021 IRC matches each design wind speed to the classes allowed:
| Max ultimate design wind speed | ASTM D7158 class | ASTM D3161 class |
|---|---|---|
| 110 to 116 mph | D, G or H | A, D or F |
| 129 mph | G or H | A, D or F |
| 142 to 155 mph | G or H | F |
| 168 to 194 mph | H | F |
The packaging must carry a label showing the standard and the class. If it does not, the inspector can reject the roof.
What Colorado jurisdictions require
- Colorado Springs and the Pikes Peak region: PPRBD designs homes for 130 mph ultimate wind speed, Exposure C. That falls in the 142 mph row, so shingles need D7158 Class G or H, or D3161 Class F. See Colorado Springs roofing codes.
- City and County of Denver: wind zones run by street. East of Federal Boulevard needs a 115 mph rating, Federal to Sheridan 125 mph, and Sheridan to Kipling 140 mph, with D7158 Class D, G or H depending on the zone. Our Denver roofing codes page has the rest.
- Littleton: 136 mph ultimate design wind speed, and the city requires D7158 Class H with six nails per shingle. See the Littleton roof code.
- Castle Rock: the Town lists 115 mph ultimate wind speed in Exposure B under the 2018 IRC. See Castle Rock roofing codes.
- Highlands Ranch and unincorporated Douglas County: high-wind nailing is required above 7,000 feet. See the Highlands Ranch roofing code.
What the label does not tell you
- Installation matters as much as the class. A Class H shingle nailed high, or without a sealed starter course at the eaves and rakes, will not perform like the test. Wind lifts the edges first.
- Cold delays sealing. Shingles rely on a heat-activated sealant strip. Winter installs may need hand sealing; see cold weather roof installs.
- Wind class is not hail class. Impact resistance is a separate test (UL 2218). Our Class 4 shingle comparison covers that side.
Why this page changed
The 2011 version of this article cited the 2006 IRC and argued that D3161 ratings were unreliable because of the test deck. The code has moved on: D7158 is now the primary standard, and local jurisdictions publish the required class. We replaced the opinion with the current table.
When we replace a roof, we confirm the required class for your address, show you the label on the bundles, and install a windstorm starter strip as part of the Integrity Roofing System. Preparing an existing roof for wind season? Read spring wind prep for Colorado Springs.
Integrity Roofing and Painting is veteran-owned and family-run since 1990, an Owens Corning Platinum Preferred contractor with 650+ Google reviews. Book a free inspection at (719) 488-2800, or in Denver at (303) 209-0152; we reach out the same business day.
Sources: 2021 IRC Chapter 9, Sections R905.2.4.1 and R905.2.6, Table R905.2.4.1; PPRBD, Basic Design Information (updated 06/30/2026); City and County of Denver, Roofing Guide and Checklist (updated 4/11/2024); City of Littleton, Policy #24-001 (5th revision, 5/21/2026); Town of Castle Rock, Building for Homeowners FAQ; Douglas County Building Division, Roofing Permits.
