Technical Booklet H Stairs Ramps Guarding and Protection from Impact·Page 17·2.7
Complementary steps - maximum flight length
A flight of steps must have at least 2 rises and no more than 12 rises (if going is less than 350 mm) or 18 rises (if going is 350 mm or more).
A flight of steps should have not less than 2 rises or more than –
(a) 12 rises where the going of each step is less than 350 mm; or
(b) 18 rises where the going of each step is 350 mm or more.
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