Roofing Permit (Reroof) in Helena, Montana

Helena requires a roofing permit (reroof) for: Roof replacement must include removal of all existing layers of roof covering and underlayment down to the roof deck (2021 IRC R908.3), except where an existing adhered ice-barrier membrane may remain and be covered with an additional layer; Installing a new roof covering OVER an existing roof covering is permitted only where 2021 IRC Section R908.3.1 compliance is followed — contact the Building Division for requirements; Ice barrier underlayment required per Montana DLI Technical Advisory T1-16 and 2021 IRC R905.1.2: at least two layers of cemented underlayment or a self-adhering polymer-modified bitumen sheet, extending from the lowest roof edges to at least 24 inches inside the exterior wall line (exception: unconditioned detached accessory structures); Attic/rafter space ventilation required per 2021 IRC R806.1-R806.3: minimum net free ventilating area of 1/150 of vented attic space (or 1/300 with a Class I/II vapor retarder and proper ventilator placement); Drip edge required at eaves and gables per 2021 IRC R905.2.8.5, overlapped minimum 2 inches, extending minimum 0.25 inch below roof sheathing and 2 inches up the roof deck, mechanically fastened at maximum 12 inches on-center; Flashing must be installed per approved manufacturer instructions to prevent moisture entry at walls, parapets, and roof penetrations (2021 IRC R903.2 and R908.6). If your project isn't listed, confirm with City of Helena — Community Development Department, Building Division at (406) 447-8438 before starting work.

In Helena, the published Roofing Permit Fee — valuation-based is: Per Ordinance 3134 Building Permit Fee Tabulation table (same table used for building permits generally). These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Plan review for a roofing permit (reroof) in Helena typically runs 1–3 business days. This is an estimate, not a published figure — confirm current review times with City of Helena — Community Development Department, Building Division at (406) 447-8438.

You'll need: Re-Roofing Application. Depending on your project, Helena may also ask for: Roofing and Re-Roofing Code Requirements (2021 IRC). See the required-documents checklist on this page for details on each.

Helena requires 1 inspection(s) for a roofing permit (reroof), in order: Final (Roof). Schedule each through City of Helena — Community Development Department, Building Division ((406) 447-8438).

Apply through City of Helena — Community Development Department, Building Division at 316 N. Park Avenue, Room 435, Helena, MT 59623. Phone: (406) 447-8438, email: CityBuilding@helenamt.gov. Office hours: City County Building, 316 N Park Ave, Helena, MT 59623; applications and permits also processed online via Civic Access (helenamt.gov/business/civic-access/). Official information: https://www.helenamt.gov/Departments/Community-Development/Building.

Helena, Montana has adopted: 2021 International Building Code (IBC) — Montana statewide adoption, effective June 11, 2022; enforced by the City of Helena within city limits under its DLI-certified Building Code Enforcement Program; 2021 International Residential Code (IRC), for One- and Two-Family Dwellings — Montana statewide adoption, effective June 11, 2022; City of Helena Building Division is the local Authority Having Jurisdiction (AHJ) for one- and two-family dwellings under IRC Chapters 8 and 9, including roofing/re-roofing; 2021 International Existing Building Code (IEBC) — Montana statewide adoption, effective June 11, 2022; ICC A117.1-2017 (Accessibility) — Montana statewide adoption, effective June 11, 2022; 2021 Uniform Plumbing Code (UPC) — Montana statewide adoption, effective June 11, 2022; City of Helena is certified to enforce plumbing (P) within city limits; 2021 International Mechanical Code (IMC) — Montana statewide adoption, effective June 11, 2022; City of Helena is certified to enforce mechanical (M) within city limits; 2021 International Fuel Gas Code (IFGC) — Montana statewide adoption, effective June 11, 2022; 2020 National Electrical Code (NEC) — Montana statewide adoption, effective June 11, 2022 (Technical Advisory NEC_TIA-23-3_210.8 issued August 12, 2022); City of Helena is certified to enforce electrical (E) within city limits; 2021 International Energy Conservation Code (IECC) — Montana statewide adoption, effective June 11, 2022; 2021 International Swimming Pool and Spa Code (ISPSC) — Montana statewide adoption, effective June 11, 2022; 2021 Wildland Urban Interface (WUI) Code — Montana statewide adoption, effective June 11, 2022 (Helena is NOT listed as WUI-certified; WUI enforcement in Helena's jurisdiction area is not confirmed — see notes); Statewide code administered by the Montana Department of Labor & Industry (DLI), Business Standards Division, Building Codes Program (formerly/also referenced as the Building Codes Bureau) — Mont. Code Ann. Title 50, Chapter 60, Parts 1-4. Local amendments apply — see the Helena overview page for the full list.

The 2021 International Residential Code (IRC), Chapters 8 and 9, for one- and two-family dwellings, enforced by the City of Helena Building Division. Structures with three or more dwelling units and commercial buildings instead follow the 2021 International Building Code (IBC) Chapter 15.