Centennial Roofing Codes: Permits, Inspections, and Requirements
Adopted building and energy codes, permit rules, and roofing requirements for Centennial, Arapahoe and Douglas Counties. Rows below reflect our reading of the jurisdiction's own published sources, linked at the bottom of the page.
Building department
303-754-3358Inspection line
303-754-3358Permit line
303-754-3358Official department
Live code pageCentennial roofing code requirements
- What this jurisdiction requires
- 2021 IBC and 2021 IRC
- What this jurisdiction requires
- 2018 IECC
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Class A
- What this jurisdiction requires
- 90 MPH Sustained/110 MPH 3-second gusts
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Yes, with one story access
- What this jurisdiction requires
- Yes, inspection required at 25% to 75% shingled for concrete, tile, and shake shingle, metal, and flat roofs.
- What this jurisdiction requires
- No
- What this jurisdiction requires
- One layer
- What this jurisdiction requires
- Single layer only
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- ½ inch gap
- What this jurisdiction requires
- Required
- What this jurisdiction requires
- Required
- What this jurisdiction requires
- Ice barrier required at eaves per the IRC
- What this jurisdiction requires
- Two layers of underlayment
- What this jurisdiction requires
- One layer of underlayment
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Both
- What this jurisdiction requires
- 90 pound
- What this jurisdiction requires
- Ice and water under metal
- What this jurisdiction requires
- Required where the roof meets a wall
- What this jurisdiction requires
- 30 inch or greater width
- What this jurisdiction requires
- No
- What this jurisdiction requires
- Required, installed to manufacturer specifications
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Required on new construction under the 2018 IECC
- What this jurisdiction requires
- Required per IRC attic ventilation provisions
| Requirement | What this jurisdiction requires |
|---|---|
| Current building code | 2021 IBC and 2021 IRC |
| Current energy code | 2018 IECC |
| Building permit required | Yes |
| Roof system fire rating (residential) | Class A |
| Minimum wind speed rating for asphalt shingles | 90 MPH Sustained/110 MPH 3-second gusts |
| Requires wind nailing | Yes |
| Inspectors carry ladders for the final | Yes, with one story access |
| Requires midroof (in progress) inspection | Yes, inspection required at 25% to 75% shingled for concrete, tile, and shake shingle, metal, and flat roofs. |
| Requires a sheathing / decking inspection | No |
| Maximum layers of asphalt shingles permitted | One layer |
| Maximum layers of flat roof material permitted | Single layer only |
| Requires solid sheeting over spaced decking | Yes |
| Sheeting gap requirement | ½ inch gap |
| Requires drip edge | Required |
| Requires rake / gable metal edging | Required |
| Self adhering underlayment (ice and water shield) | Ice barrier required at eaves per the IRC |
| Underlayment required 2:12 up to 4:12 | Two layers of underlayment |
| Underlayment required 4:12 and above | One layer of underlayment |
| Rolled roofing allowed on low slope over living space | Yes |
| Type of valleys allowed | Both |
| Valley material required for closed valleys | 90 pound |
| Valley material required for open valleys | Ice and water under metal |
| Kick-out required on step flashing | Required where the roof meets a wall |
| Chimney cricket requirement | 30 inch or greater width |
| Minimum curb height requirement | No |
| Requires ridge cap | Required, installed to manufacturer specifications |
| Requires ventilation to meet code | Yes |
| Blower door test when increasing ventilation to code | Required on new construction under the 2018 IECC |
| Requires soffit / eave vents | Required per IRC attic ventilation provisions |
Last checked September 2, 2026. This reflects published sources at that date, not an official ruling. Code adoptions change, so confirm with the Centennial building department before you pull a permit.
What Centennial requires, in plain language
Centennial builds to the 2021 IBC and 2021 IRC. That edition, not the newest code published nationally, is the rulebook an inspector in Arapahoe and Douglas Counties holds your roof to. Energy work on the same permit follows the 2018 IECC.
Layer limit in Centennial: One layer. This is the line item that moves a bid the most. If your existing roof is already at the limit, the deck gets stripped before new material goes down, and the labor plus dump fees belong in the written price. Flat roof sections are capped at Single layer only.
Wind is what Centennial tests shingles against. Shingles need a 90 MPH Sustained/110 MPH 3-second gusts rating. Wind nailing: Yes.
Underlayment and edge metal are where roofs fail inspection. Ice and water shield: Ice barrier required at eaves per the IRC. On 2:12 to 4:12 slopes: Two layers of underlayment. On 4:12 and steeper: One layer of underlayment. Drip edge: Required.
Centennial Ordinance 2023-O-06 adopted the 2021 IBC, IRC, IMC, IFGC, IPC and IFC, and kept the energy code on the 2018 IECC.
Installation details above come from our building department field survey for Centennial, last updated 8/22/18. Code editions and contacts are refreshed from the department directly. Always confirm the details on your permit before work starts, since departments amend requirements on their own schedule.
Sources
These links go straight to the jurisdiction, so you always have the real-time source. Adoptions and amendments change on their schedule, not ours. Always confirm before permitting.
Last checked September 2, 2026. This is our best read of published sources, not an official ruling. Confirm with the Centennial building department before you pull a permit.