IBC Top Handrail
STAIRWAYS AND HANDRAILS
1009.1 Stairway Width.
The width of stairways shall
not be less than 44 inches (1118 mm).
1. Stairways serving an occupant load of 50 or less
shall have a width of not less than 36 inches (914
1009.11.5 Handrail Extensions.
Handrails shall return
to a wall, guard or the walking surface or shall be
continuous to the handrail of an adjacent stair flight.
Where handrails are not continuous between flights, the
handrails shall extend horizontally at least 12 inches (305 mm) beyond the top riser and continue to slope for
the depth of one tread beyond the bottom riser.
1. Handrails within a dwelling unit that is not
required to be accessible need extend only from
the top riser to the bottom riser.
Stairways shall have a minimum
headroom clearance of 80 inches (2032 mm) measured
vertically from a line connecting the edge of the nosings.
Such headroom shall be continuous above the stairway
to the point where the line intersects the landing below,
one tread depth beyond the bottom riser. The minimum
clearance shall be maintained the full width of the stairway
1009.3 Stair Treads and Risers.
Stair riser heights
shall be 7 inches maximum and 4 inches
minimum. Stair tread depths shall be 11 inches
minimum. The riser height shall be measured
vertically between the leading edges of adjacent treads.
The greatest riser height within any flight of stairs shall
not exceed the smallest by more than 0.375 inch. The tread depth shall be measured horizontally
between the vertical planes of the foremost projection
of adjacent treads and at right angle to the tread's
leading edge. The greatest tread depth within any flight
of stairs shall not exceed the smallest by more than
Clear space between a handrail
and a wall or other surface shall be a minimum of 1.5
inches (38 mm). A handrail and a wall or other surface
adjacent to the handrail shall be free of any sharp or
1009.11.7 Stairway Projections.
Projections into the
required width at each handrail shall not exceed 4.5
inches (114 mm) at or below the handrail height.
Projections into the required width shall not be limited
above the minimum headroom height required in
1009.3.1 Dimensional Uniformity.
Stair treads and
risers shall be of uniform size and shape. The tolerance
between the largest and smallest riser or between the
largest and smallest tread shall not exceed 0.375 inch
(9.5 mm) in any flight of stairs.
1012.1 Where Required.
Guards shall be located along
open-sided walking surfaces, mezzanines, industrial
equipment platforms, stairways, ramps and landings
which are located more than 30 inches (762 mm) above
the floor or grade below. Guards shall be adequate in
strength and attachment in accordance with Section
1607.7. Guards shall also be located along glazed sides
of stairways, ramps and landings that are located more
than 30 inches (762 mm) above the floor or grade below
where the glazing provided does not meet the strength
and attachment requirements in Section 1607.7.
Exception: Guards are not required for the following
1. On the loading side of loading docks or piers.
2. On the audience side of stages and raised plat-
forms, including steps leading up to the stage and
3. On raised stage and platform floor areas such as
runways, ramps and side stages used for entertainment or presentations.
4. At vertical openings in the performance area of
stages and platforms.
5. At elevated walking surfaces appurtenant to
stages and platforms for access to and utilization
of special lighting or equipment.
6. Along vehicle service pits not accessible to the
7. In assembly seating where guards in accordance
with Section 1024.14 are permitted and provided.
The radius of curvature at the leading
edge of the tread shall be not greater than 0.5 inch (12.7
mm). Beveling of nosings shall not exceed 0.5 inch (12.7
mm). Risers shall be solid and vertical or sloped from the
underside of the leading edge of the tread above at an
angle not more than 30 degrees (0.52 rad) from the
vertical. The leading edge (nosings) of treads shall project
not more than 1.25 inches (32 mm) beyond the tread
below and all projections of the leading edges shall be
of uniform size, including the leading edge of the floor
at the top of a flight.
1009.4 Stairway Landings.
There shall be a floor or
landing at the top and bottom of each stairway. The
width of landings shall not be less than the width of
stairways they serve. Every landing shall have a minimum
dimension measured in the direction of travel equal to the
width of the stairway. Such dimension need not exceed
48 inches (1219 mm) where the stairway has a straight
Guards shall form a protective barrier
not less than 42 inches (1607 mm) high, measured vertically above the leading edge of the tread, adjacent
walking surface or adjacent seat board
1009.5 Stairway Construction.
All stairways shall be
built of materials consistent with the types permitted for
the type of construction of the building, except that wood
handrails shall be permitted for all types of construction.
1009.5.1 Stairway Walking Surface.
surface of treads and landings of a stairway shall not be
sloped steeper than one unit vertical in 48 units horizontal
(2-percent slope) in any direction. Stairway treads and
landings shall have a solid surface. Finish floor surfaces
shall be securely attached.
than areas of parking structures accessible to the
public, openings in treads and landings shall not be
prohibited provided a sphere with a diameter of 1
1/8 inches (29 mm) cannot pass through the opening.
1012.3 Opening Limitations.
Open guards shall have
balusters or ornamental patterns such that a 4-inch-
diameter (102 mm) sphere cannot pass through any
opening up to a height of 34 inches (864 mm). From a
height of 34 inches (864 mm) to 42 inches (1067 mm)
above the adjacent walking surfaces, a sphere 8 inches
(203 mm) in diameter shall not pass.
1. The triangular openings formed by the riser, tread
and bottom rail at the open side of a stairway
shall be of a maximum size such that a sphere of
6 inches (152 mm) in diameter cannot pass
through the opening.
2. At elevated walking surfaces for access to and use
of electrical, mechanical or plumbing systems or
equipment, guards shall have balusters or be of
solid materials such that a sphere with a diameter
of 21 inches (533 mm) cannot pass through any
3. In areas which are not open to the public within
occupancies in Group I-3, F, H or S, balusters,
horizontal intermediate rails or other construction
shall not permit a sphere with a diameter of 21
inches (533 mm) to pass through any opening.
4. In assembly seating areas, guards at the end of
aisles where they terminate at a fascia of boxes,
balconies and galleries shall have balusters or
ornamental patterns such that a 4-inch-diameter
(102 mm) sphere cannot pass through any
opening up to a height of 26 inches (660 mm).
From a height of 26 inches (660 mm) to 42
inches (1067 mm) above the adjacent walking
surfaces, a sphere 8 inches (203 mm) in diameter
shall not pass.
1009.5.2 Outdoor Conditions.
Outdoor stairways and
outdoor approaches to stairways shall be designed so
that water will not accumulate on walking surfaces. In
other than occupancies in Group R-3, and occupancies
in Group U that are accessory to an occupancy in Group
R-3, treads, platforms and landings that are part of
exterior stairways in climates subject to snow or ice
shall be protected to prevent the accumulation of same.
1009.6 Vertical Rise.
A flight of stairs shall not have a vertical rise grater than 12 feet (3658 mm) between floor
levels or landings.
Stairways shall have handrails on
Handrail height, measured above stair
tread nosings, or finish surface of ramp slope, shall be
uniform, not less than 34 inches (864 mm) and not more
than 38 inches (965 mm).
1012.5 Mechanical Equipment.
Guards shall be
provided where appliances, equipment, fans or other
components that require service are located within 10
feet (3048 mm) of a roof edge or open side of a walking
surface and such edge or open side is located more than
30 inches (762 mm) above the floor, roof or grade
below. The guard shall be constructed so as to prevent
the passage of a 21-inch-diameter (533 mm) sphere.
1009.11.2 Intermediate Handrails.
rails are required so that all portions of the stairway width
required for egress capacity are within 30 inches (762 mm)
of a handrail. On monumental stairs, handrails shall be
located along the most direct path of egress travel.
1009.11.3 Handrail Graspability.
circular cross section shall have an outside diameter of
at least 1.25 inches (32 mm) and not greater than 2
inches (51 mm) or shall provide equivalent graspability.
If the handrail is not circular, it shall have a perimeter
dimension of at least 4 inches (102 mm) and not greater
than 6.25 inches (160 mm) with a maximum cross-
section dimension of 2.25 inches (57 mm). Edges shall
have a minimum radius of 0.01 inch (0.25 mm).
Handrail-gripping surfaces shall
be continuous, without interruption by newel posts or
This information above is reproduced from the IBC code. A-Mezz Industrial Structures is not responsible
for the accuracy of this information. This information is meant to serve as guide, not the authority of the International Building Code. For additional IBC clearification please contact your local building department.