(See Note A-9.8.4.)
(1)
Except as provided in Sentence (2) and Articles 9.8.4.6. and 9.8.4.7., tapered treads shall have a run that
(a)
is not less than 150 mm at the narrow end of the tread, and
(b)
complies with the dimensions for rectangular treads stated in Table 9.8.4.1. when measured at a point 300 mm from the centre line of the handrail at the narrow end of the tread.
(2)
Tapered treads in required exit stairs shall conform to the requirements in Article 3.4.6.9.
(3)
The depth of a tapered tread shall be not less than its run at any point and not more than its run at any point plus 25 mm.