Montana roofing: permits, codes and approvals

Montana's new construction contractor license (roofing named in the law), the 2024 IRC adopted statewide but applied to one- and two-family homes only where cities and counties opt in, and the 20-day notice and 90-day lien rules.

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1 · Product approvals

Product approvals

Montana has no state roofing product approval or listing system. Where a local building department enforces the code, inspectors rely on the IRC's labeling rules, evaluation reports (ICC-ES, UL and similar) and manufacturer instructions.

Code evaluation reports (ICC-ES, UL, IAPMO): 48 roofing reports

2 · Permit forms

City re-roof permits

No statewide re-roof permit rule. The state building code does not reach one- and two-family homes unless the city or county adopts it, so re-roof permits depend on the local building department.

BozemanThe city's re-roofing guide (2016) calls for a dry-in inspection after the ice barrier goes on and a final inspection by the building official when re-roofing is done; call the permits office before starting.

3 · Code rules

Code rules

Montana's Building Codes Division adopted the 2024 IRC (amended under ARM Title 24, Chapter 301), effective September 26, 2026. It applies to homes with fewer than five units only where a city, town or county has made it apply locally. Official adoption page ↗

Homes under five units: local adoption onlyBy law the state code does not apply to residential buildings with fewer than five dwelling units unless the local government adopts it, and the state can't enforce it on them.2024 codes effective September 26, 2026The state's current list moves the IRC, IBC, IEBC and energy code to the 2024 editions effective September 26, 2026. Bozeman's page notes jobs follow the code in effect when the permit application is submitted.Wildland-Urban Interface Code on the state listThe state's adopted code list includes the 2024 International Wildland-Urban Interface Code, effective September 26, 2026. Check with the local building department whether it applies to a given home.

5 · License and insurance

License and insurance

Montana does not have a roofing-specific license. A 2025 law (MCA Title 37, Chapter 45) requires a construction contractor license from the Department of Labor and Industry, and it names roofing and siding work.

Construction contractor license (MCA 37-45-201)You may not work as a construction contractor without a current license from the Department of Labor and Industry. The application needs proof of workers' comp compliance and the owners' or officers' names.Roofing is covered (MCA 37-45-102)The definition of construction contractor expressly includes installing or repairing roofing or siding for others.Exemptions: small jobs and solo contractorsExempt: casual or minor jobs under $2,500 total (not split to dodge the law), employees of a registered contractor, and independent contractors with no employees (who may register voluntarily).Department registration pageThe Department's page still describes a Construction Contractor Registration for contractors with employees, a $70 non-refundable application fee, workers' comp coverage, and fines up to $500 per violation.

6 · Lien and contract forms

Lien and contract rules

Subs and suppliers on homes must send a notice of right to claim lien within 20 days of first furnishing; a roofer contracting directly with the owner is exempt. Liens are filed within 90 days and enforced within 2 years.

Notice of right to claim lien (MCA 71-3-531)Required to claim a lien, sent to the owner no later than 20 days after first furnishing labor or materials. Not required for the original contractor hired directly by the owner, laborers, or commercial jobs.Late notice limits the lienIf the notice is late, the lien covers only work or materials furnished in the 20 days (45 days for some lender-funded, non-owner-occupied jobs) before the notice was given.File the lien within 90 days (MCA 71-3-535)File with the county clerk and recorder no later than 90 days after your last furnishing or after the owner files a notice of completion, and certify that a copy was served on the owner of record.Enforce within 2 years (MCA 71-3-562)Any court action on a construction lien must be started within 2 years from the date the lien was filed.

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Public records, last checked Oct 23, 2026. Always verify on the official source before you permit.