Windsor Roofing Codes: Permits, Inspections, and Requirements
Adopted building and energy codes, permit rules, and roofing requirements for Windsor, Weld and Larimer Counties. Rows below reflect our reading of the jurisdiction's own published sources, linked at the bottom of the page.
Windsor roofing code requirements
- What this jurisdiction requires
- 2018 IBC and 2018 IRC, verify the current edition
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Class A
- What this jurisdiction requires
- 90 MPH 3 second gusts
- What this jurisdiction requires
- ASTM D 7158, ASTM 3161 Class A, D, F
- What this jurisdiction requires
- Per manufacturer
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Yes - exception: if decking has rotted and been replaced
- What this jurisdiction requires
- One layer
- What this jurisdiction requires
- One layer
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- ¼ inch gap
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- 1 x 2 - cover sheathing by ¼ inch
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- No
- What this jurisdiction requires
- 19 inch overlap of 15#
- What this jurisdiction requires
- 15# - for asphalt: two layers on 2:12 - 4:12 non asphalt: varies per code
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Both
- What this jurisdiction requires
- Either
- What this jurisdiction requires
- Either
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- 30" or greater width
- What this jurisdiction requires
- No
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- Yes
- What this jurisdiction requires
- A,B or C depending on building construction classification
| Requirement | What this jurisdiction requires |
|---|---|
| Current building code | 2018 IBC and 2018 IRC, verify the current edition |
| Building permit required | Yes |
| Roof system fire rating (residential) | Class A |
| Minimum wind speed rating for asphalt shingles | 90 MPH 3 second gusts |
| ASTM standard for wind rating | ASTM D 7158, ASTM 3161 Class A, D, F |
| Requires a manufacturer wind warranty | Per manufacturer |
| Requires wind nailing | Yes |
| Requires midroof (in progress) inspection | Yes |
| Requires a sheathing / decking inspection | Yes - exception: if decking has rotted and been replaced |
| Maximum layers of asphalt shingles permitted | One layer |
| Maximum layers of flat roof material permitted | One layer |
| Requires solid sheeting over spaced decking | Yes |
| Sheeting gap requirement | ¼ inch gap |
| Requires drip edge | Yes |
| Minimum drip edge size | 1 x 2 - cover sheathing by ¼ inch |
| Requires rake / gable metal edging | Yes |
| Self adhering underlayment (ice and water shield) | No |
| Underlayment required 2:12 up to 4:12 | 19 inch overlap of 15# |
| Underlayment required 4:12 and above | 15# - for asphalt: two layers on 2:12 - 4:12 non asphalt: varies per code |
| Rolled roofing allowed on low slope over living space | Yes |
| Type of valleys allowed | Both |
| Valley material required for closed valleys | Either |
| Valley material required for open valleys | Either |
| Kick-out required on step flashing | Yes |
| Chimney cricket requirement | 30" or greater width |
| Minimum curb height requirement | No |
| Requires positive drainage | Yes |
| Requires ventilation to meet code | Yes |
| Requires soffit / eave vents | Yes |
| Special conditions | A,B or C depending on building construction classification |
Last checked September 2, 2026. This reflects published sources at that date, not an official ruling. Code adoptions change, so confirm with the Windsor building department before you pull a permit.
What Windsor requires, in plain language
Windsor builds to the 2018 IBC and 2018 IRC, verify the current edition. That edition, not the newest code published nationally, is the rulebook an inspector in Weld and Larimer Counties holds your roof to.
Layer limit in Windsor: 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 One layer.
Wind is what Windsor tests shingles against. Shingles need a 90 MPH 3 second gusts rating. Rating is proven under ASTM D 7158, ASTM 3161 Class A, D, F. Wind nailing: Yes. Manufacturer wind warranty: Per manufacturer.
Underlayment and edge metal are where roofs fail inspection. Ice and water shield: No. On 2:12 to 4:12 slopes: 19 inch overlap of 15#. On 4:12 and steeper: 15# - for asphalt: two layers on 2:12 - 4:12 non asphalt: varies per code. Drip edge: Yes. Minimum drip edge size 1 x 2 - cover sheathing by ¼ inch.
Windsor Ordinance No. 2019-1590 adopted the 2018 IBC and IRC and the related International Codes by reference into Municipal Code Chapter 18. Confirm with the department whether a newer edition has been adopted since.
Installation details above come from our building department field survey for Windsor, last updated 1/7/2019. 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.
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Nearby jurisdictions
Last checked September 2, 2026. This is our best read of published sources, not an official ruling. Confirm with the Windsor building department before you pull a permit.