OSHA | IBC | IRC | Stairs, Railings, Guardrails

OSHA, IBC, and IRC stair and platform requirements.

OSHA   Occupational Safety and Health Administration

Equipment Access – industrial equipment access stairs, catwalks, and platforms are often simply referred to as OSHA Stairs. MSHA (Mine Safety and Health Administration) and IMC (International Mechanical Code) stairs also fit into this same category. OSHA stair standards are more extensive than the other two therefore all three would qualify as OSHA compliant stairs.

IBC   International Building Code

Egress Stair Systems – defined as a continuous and unobstructed path of travel from any occupied portion of a building or structure to a public way. IBC code applies to these situations with some differences depending on occupancy types.

IRC   International Residential Code

Less extensive to the IBC codes, the IRC codes are specific to only residential properties. This comprehensive code applies only to single-family houses, two-family houses, and buildings consisting of three or more town-house units. Buildings within the scope of IRC are limited to 3 stories above grade plane. Any larger or taller residential buildings fall under the IBC requirements.

Note: In many public area stairs any combination of ADA, NFPA, ANSI, and ASTM standards may apply. Each locality may have its own list of such requirements to be followed.

NON-STANDARD   steep stairs, spiral stairs, and ladders

OSHA and IBC define different types of stairways and ladders that are not classified as standard stairs. Non-standard stairs are used only when the employer can demonstrate that it is not feasible to provide standard stairs. The final rule is based on specific case-by-case evaluations and demonstrations it is not possible to use standard stairs.

Fixed Ladder: A ladder with rails or individual rungs that is permanently attached to a structure, building, or equipment.

Ship Stair: A stair that is equipped with treads, stair rails, and open risers, and has a slope that is between 50 and 70 degrees from the horizontal.

Alternating Tread-Type Stair: A type of stair consisting of a series of treads that usually are attached to a center support in an alternating manner such that users typically do not have both feet on the same level while using stair.

Spiral Stair: A stairway having a closed circular form in its plan view with uniform section-shaped treads attached to minimum-diameter supporting column.

Access Egress
Overhead Clearance: min 80 in
Stairway Slope: 30° to 50° 20° to 38°
Stair Rise: max 9.5 in max 7 in
Tread Depth: min 9.5 in min 11 in
Stair Width: min 22 in min 36 in
Stair Over-Run: 1.25 in
Stair Rail Height: 36 - 38 in 42 in min 34 in
Handrail Height: 36 to 38 in 34 to 38 in
Handrail Diameter: min 1.5 in 1.25 in to 2 in
Top Extension: N/A 12 in horiz N/A
Bottom Extension: N/A sloped = tread depth N/A
Baluster Spacing: max 19 in max 4 in sphere
Midrail Spacing: max 21 in N/A
Bottom Rail Gap: N/A max 6 in sphere
Finger Clearance: min 2.25 in min 1.5 in
Access Egress
Required At: 48" High 30" High
Guardrail Height: 42 in min 36 in
Post Size: min 1.5 in dia N/A
Post Centers: max 8 ft N/A
Baluster Spacing: max 19 in max 4 in sphere
Midrail Spacing: max 21 in N/A
Toeboard Height: min 3.5 in N/A
Toeboard Gap: 0.25 in N/A
Access Egress
Overhead Clearance: min 80 in
Stair Section Height: max 12 ft without platform
Landing Travel: min = stair width
Door Swing Clearance: min = stair width ÷ 2
Door Opening Clearance: min 7" from edge of platform
30.6° 6.50" 11.00"
32.1° 6.75" 10.75"
33.7° 7.00" 10.50"
35.3° 7.25" 10.25"
36.9° 7.50" 10.00"
38.5° 7.75" 9.75"
40.1° 8.00" 9.50"
41.7° 8.25" 9.25"
43.4° 8.50" 9.00"
45.0° 8.75" 8.75"
46.6° 9.00" 8.50"
48.3° 9.25" 8.25"
49.9° 9.50" 8.00"
osha stairway requirements drawing

OSHA Stairs   Side View

ibc dimension requirements drawing

IBC Stairs   Side View

  • 80 in minimum clearance to any overhead obstruction required above any stair, platform, or walkway
  • 30 in minimum stair width or platform width
  • 22 in minimum platform width beyond door swing
  • Guardrail and Handrail required to withstand 200 lb force applied downward or outward direction
  • Under 44 in stair width requires minumum one handrail
  • 44 in to 88 in width stair requires handrail on each side
  • Over 88 in width stair requires handrail on each side plus intermediate handrail
  • IBC requires handrail on both sides of all stairways, and all tread area must be within 30" of a handrail
  • Guardrail height to be 42 in (+/- 3 in)
  • Handrial height to be 36 in to 38 in
  • Egress railings require 12 in horizontal top extension
  • Egress railings require bottom sloped extension one tread width beyond bottom riser
  • Ramps require 12 in horizontal top and bottom extensions
  • NOTE: OSHA stair systems installed after 2017 require both Guardrail and Handrail
top view drawing of osha stair section

OSHA and IBC Stairs   Top View