Section R. 400.10615 - Interior finishRule 615.
(1) The following alphabetical classification of finished materials for flame spread and smoke development, as determined by the tunnel test in accordance with the provisions of the national fire protection association pamphlet no. 255, 1979; American society of testing materials standard E-84-77A, 1978; or underwriters laboratories standard no. 723, 1977, shall be used to classify interior finishes in residential group home facilities: Class Flame Spread Smoke Developed A 0-25 0-450 B 26-75 51-450 C 76-200 126-450 The same alphabetical classification is used to classify combustibility of prefabricated acoustical tile units, as determined by federal specifications test no. SS-S-118a.(2) The classification of interior finish materials as to their flame spread and smoke development shall be that of the basic material used, without regard to subsequently applied paint or other coverings, except where such paint or other covering is of such a character or thickness where applied so as to affect the material classification. Finishes such as lacquer, polyurethane-based materials, or unapproved wall coverings shall not be used.(3) In a newly constructed, remodeled, or converted residential group home, an interior finish classification shall be that of the basic material used, without regard to subsequently applied paint or other covering in an attempt to meet the classification.(4) In an existing residential facility, if an interior finish at the time these rules take effect does not comply with the provisions of subrule (3) of this rule and if an interior finish is applied to or furred out not more than 1 inch from a continuous noncombustible backing, an interior finish may have the surface protected with an approved fire-retardant coating so as to meet the interior finish requirements.(5) Interior finishes and materials shall be at least class C throughout.Mich. Admin. Code R. 400.10615