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FIRE EGRESS EXIT STAIRS |
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Clear width of internal access staircase with mezzanine level shall not be less than 1000mm.The maximum width of exit staircases shall be not more than 2000mm.
Where staircases exceed 2000mm in width, handrails shall be used to divide the staircase into sections of not less than 1000mm of width or more than 2000mm of width. For the purpose of determining the exit capacity of a staircase that is wider than 2000mm that forms part of the required means of escape from any storey of the building, that part of its width in excess of 2000mm shall not be taken into account. |
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| Where staircases exceed 2000mm in width, handrails shall be used to divide the staircase into sections of not less than 1000mm of width or more than 2000mm of width. |
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| The width of staircase of 2500mm is being divided into 2 sections of 1250mm each by the introduction of an intermediate handrail, although the staircase is 2500mm clear it is still computed as 2000mm only. Dividing staircase wider than 2000mm enables better crowd control and orderly evacuation in times of emergency. |
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Riser height and tread width shall be constant in any flight of stairs from storey to storey. There shall be minimum 2 risers in any flight of stair. Many accidents have
resulted from irregularities in staircase. There should be no design irregularities. Riser height is the vertical height between tread nosings. Tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads, and at a right angle to the tread’s leading edge. |
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Landings
* exit staircases shall be provided with landings at intervals of not more than 16 risers or less than 2 risers at every floor level, and
* the minimum width of a landing and length shall be not less than the width of the staircase, and
* on a straight-run exit staircase, the distance between risers of the upper flight and lower flight need not be more than 1m.
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