Stairs nosing
Approved Document K - Protection from falling, collision and impact defines the ‘nosing’ of stairs as ‘the leading edge of a stair tread’.
The pitch of stairs is the angle of inclination between the horizontal and a line connecting the nosings.
[Image: The elements of stairs]
For buildings other than dwellings, step nosings should be made visually apparent by using a contrasting material on both the tread and the riser a minimum of 55 mm wide. If possible, step nosings that protrude over the tread below should be avoided. If the nosing does protrude, it should be by no more than 25 mm
[Image: Examples of suitable tread profiles]
For common access areas in buildings that contain flats step nosings should be visually apparent, using a material that contrasts visually, 50 - 65 mm wide on the tread and 30 - 55 mm on the riser. A suitable tread nosing profile, should be used.
Approved document M, Volume 1: Dwellings (2015 edition incorporating 2016 amendments), defines a ‘suitable tread nosing’as; ‘Nosings that conform with one of the options shown in diagram 1.2 of approved document K’
On an alternating tread stairs alternating steps should be uniform with parallel nosings.
A pitch line is a line that connects the nosing of the treads of a stair.
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