(1) Except as otherwise required or permitted by this Subsection, the flame-spread rating of interior wall and ceiling finishes, including glazing and skylights, shall be not more than 150 and shall conform to Table 3.1.13.2.
                                
                                
                                (2) Except as permitted by Sentence (3), doors, other than those in Group A, Division 1 occupancies, need not conform to Sentence (1) provided they have a flame-spread rating not more than 200.
                                
                                
                                (3) Doors within a dwelling unit need not conform to Sentences (1) and (2).
                                
                                
                                (4) Up to 10% of the total wall area and 10% of the total ceiling area of a wall or ceiling finish that is required by Sentence (1) to have a flame-spread rating less than 150 is permitted to have a flame-spread rating not more than 150, except that up to 25% of the total wall area of lobbies described in Sentence 3.4.4.2. (2) is permitted to have a flame-spread rating not more than 150.
                                
                                
                                (5) Except in the case of Group A, Division 1 occupancies, combustible doors, skylights, glazing and light diffusers and lenses shall not be considered in the calculation of wall and ceiling areas described in Sentence (4).