Stair Handrail Width

Required stair width in turn depends on the number of occupants expected to exit the building.

Stair handrail width.

Maximum 12 3 vertical height rise for a flight of stairs. For a stairway with a railing on just one side stairway width can be a bit smaller with a clear width of 31 5 in the space below the handrail height. Ibc 1012 7 clear width between handrails on ramps note that this is a minimum not a maximum width. Stair widths are based on the use and occupancy loads of adjacent spaces and must be serviced with handrails on one or both sides depending on the stair width.

The handrail itself should be easy to grip with a minimum diameter of 1 1 4. Private stairways 30 inches 762 or less in height may. Maximum stairway width permitting a handrail on just one side. On ramps the clear width between handrails shall be 36 inches 914 mm minimum.

For example the minimum hand clearance between the railing and the wall that it is mounted on is 1 1 2 inches. Maximum 4 1 2 inch handrail projection into stairway width on either side. These calculations give you the required combined width of all exit stairs serving that floor. Under the ibc there must also be an intermediate handrail for every 60 inches of stair width at any place on a set of stairs a handrail must be no more than 30 inches away.

Maximum 7 3 4 inch stair riser height. Minimum 6 8 headroom height clearance for stairway. The same height rules apply to stairs and the inspector measures the handrail height from nose of the stair tread. For stairs serving a single user typically private residential a minimum of 36 91 cm is required.

If the stairway serves a floor with an occupant load of less than 50 the minimum clear width is reduced to 36. Intermediate handrails shall be spaced approximately equally across the entire width of the stairway. This space is shown with the green arrow in our photograph below. In general public spaces a minimum of 44 112 cm must be met providing ample space for one person and allowing the tight.

Stairways less than 44 inches 1118 mm in width or stairways serving one individual dwelling unit in group r division 1 or 3 occupancy or a group r division 3 congregate residence may have one handrail. Yet if the railing is pushed out too far there is the risk of violating another section of code that provides for 27 inches of walking width between the two railings of a double railing staircase. The top rail must be at least 42 inches in height 1910 29 f 1 ii b and the handrail must be 30 to 38 inches in height 1910 29 f 1 i as measured at the leading edge of the stair tread to the top surface of the rail.