Administrative Rules of Montana
Department 24 - LABOR AND INDUSTRY
Chapter 24.321 - WILDLAND URBAN INTERFACE FIRE MITIGATION
Subchapter 24.321.3 - Wildland Urban Interface Fire Mitigation
Rule 24.321.309 - VENTS
Current through Register Vol. 18, September 20, 2024
(1) Ventilation openings in vertical exterior walls, attics, foundations, or underfloor areas shall not exceed 144 square inches each. Attic ventilation openings shall not be located in soffits, eave overhangs, between rafters at eaves, or other overhang areas.
(2) All such vents shall be covered with noncombustible corrosion-resistant mesh with openings not to exceed 1/4 inch or shall be designed and approved to prevent ember or flame penetration into the structure. Vents shall not be placed in walls that face heavy vegetative fuels.
(3) If a structure is not located in a designated WUI, this rule does not apply.
50-60-901, MCA; IMP, 76-3-504, MCA;