Commerce City Roofing Codes: Permits, Inspections, and Requirements
Adopted building and energy codes, permit rules, and roofing requirements for Commerce City, Adams County. Rows below reflect our reading of the jurisdiction's own published sources, linked at the bottom of the page.
Building department
303-289-3683Inspection line
303-289-3683Permit line
303-289-3683Official department
Live code pageCommerce City roofing code requirements
- What this jurisdiction requires
- 2021 IBC and 2021 IRC, adopted as the Commerce City Building Code
- What this jurisdiction requires
- 2021 IECC
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- A roofing/re-roofing permit is only for roof new covering installations and/or replacement of existing roof coverings. Sheathing/decking replacement is allowed with roofing or re-roofing permit provided it is included in the description of work. Any other work (e.g. structural modifications) requires a separate permit.
- What this jurisdiction requires
- Class C
- What this jurisdiction requires
- 90 MPH or 3 second gust
- What this jurisdiction requires
- No
- What this jurisdiction requires
- No
- What this jurisdiction requires
- Yes, but only with one story access.
- What this jurisdiction requires
- Yes, required at 50% complete.
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Two layers
- What this jurisdiction requires
- Two layers
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- 3/8" gap
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- 1 x 2
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- No
- What this jurisdiction requires
- 19" overlap of 30 pound
- What this jurisdiction requires
- 15 pound
- What this jurisdiction requires
- Open and closed
- What this jurisdiction requires
- 90 pound
- What this jurisdiction requires
- 90 pound under metal
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- None
- What this jurisdiction requires
- Yes, attic ventilation must be brought up to current code on tear offs to deck.
- What this jurisdiction requires
- No
- What this jurisdiction requires
- Class C allowed on one and two-family dwellings. Other roof covering classifications vary based on the type of construction as defined in the 2009 IBC
| Requirement | What this jurisdiction requires |
|---|---|
| Current building code | 2021 IBC and 2021 IRC, adopted as the Commerce City Building Code |
| Current energy code | 2021 IECC |
| Building permit required | Yes |
| Other or special permits required | A roofing/re-roofing permit is only for roof new covering installations and/or replacement of existing roof coverings. Sheathing/decking replacement is allowed with roofing or re-roofing permit provided it is included in the description of work. Any other work (e.g. structural modifications) requires a separate permit. |
| Roof system fire rating (residential) | Class C |
| Minimum wind speed rating for asphalt shingles | 90 MPH or 3 second gust |
| Requires a manufacturer wind warranty | No |
| Requires wind nailing | No |
| Inspectors carry ladders for the final | Yes, but only with one story access. |
| Requires midroof (in progress) inspection | Yes, required at 50% complete. |
| Requires a sheathing / decking inspection | Yes |
| Maximum layers of asphalt shingles permitted | Two layers |
| Maximum layers of flat roof material permitted | Two layers |
| Requires solid sheeting over spaced decking | Yes |
| Sheeting gap requirement | 3/8" gap |
| Requires drip edge | Yes |
| Minimum drip edge size | 1 x 2 |
| Requires rake / gable metal edging | Yes |
| Self adhering underlayment (ice and water shield) | No |
| Underlayment required 2:12 up to 4:12 | 19" overlap of 30 pound |
| Underlayment required 4:12 and above | 15 pound |
| Type of valleys allowed | Open and closed |
| Valley material required for closed valleys | 90 pound |
| Valley material required for open valleys | 90 pound under metal |
| Kick-out required on step flashing | Yes |
| Chimney cricket requirement | Yes |
| Minimum curb height requirement | None |
| Requires ventilation to meet code | Yes, attic ventilation must be brought up to current code on tear offs to deck. |
| Requires soffit / eave vents | No |
| Special conditions | Class C allowed on one and two-family dwellings. Other roof covering classifications vary based on the type of construction as defined in the 2009 IBC |
Last checked September 2, 2026. This reflects published sources at that date, not an official ruling. Code adoptions change, so confirm with the Commerce City building department before you pull a permit.
What Commerce City requires, in plain language
Commerce City builds to the 2021 IBC and 2021 IRC, adopted as the Commerce City Building Code. That edition, not the newest code published nationally, is the rulebook an inspector in Adams County holds your roof to. Energy work on the same permit follows the 2021 IECC.
Layer limit in Commerce City: Two layers. 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 Two layers.
Wind is what Commerce City tests shingles against. Shingles need a 90 MPH or 3 second gust rating. Wind nailing: No. Manufacturer wind warranty: No.
Underlayment and edge metal are where roofs fail inspection. Ice and water shield: No. On 2:12 to 4:12 slopes: 19" overlap of 30 pound. On 4:12 and steeper: 15 pound. Drip edge: Yes. Minimum drip edge size 1 x 2.
The 2021 Commerce City Building Code, which incorporates the 2021 International Codes and the 2023 NEC, is in effect through Municipal Code Chapter 5, Article IV.
Installation details above come from our building department field survey for Commerce City, last updated 9/16/2018. 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
- https://www.c3gov.com/Business-Development/Building-Permits-Inspections
- https://library.municode.com/co/commerce_city/codes/municipal_code
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.
Keep going
Nearby jurisdictions
Last checked September 2, 2026. This is our best read of published sources, not an official ruling. Confirm with the Commerce City building department before you pull a permit.