Mont. Admin. r. 24.321.306Download PDFCurrent through Register Vol. 1, January 10, 2025Rule 24.321.306 - CHIMNEYS AND FLUES(1) An approved spark arrester constructed of a minimum 12-gauge welded-wire or woven-wire mesh, with openings not exceeding 1/2 inch shall be installed on every fireplace and wood stove chimney and flue.Mont. Admin. r. 24.321.306NEW, 2011 MAR p. 319, Eff. 2/25/11.50-60-901, MCA; IMP, 76-3-504, MCA;