Temporary construction stairway dimensions

Temporary stairs still need a safe, regular geometry

Construction crews use temporary stairways to move between working levels before permanent stairs are complete. A makeshift flight with uneven steps, a missing landing, or an open edge creates a fall hazard even if workers use it only briefly. OSHA’s construction stairway rule applies to stairways used in construction work. It specifies consistent risers and treads, landings for stairs not intended to remain in the structure, slope limits, and rails once the stairway reaches its trigger.

Stairs must be installed between 30 and 50 degrees from horizontal. Riser height and tread depth must be uniform within each flight, including any foundation structure used as one or more treads. Variations in riser height or tread depth may not exceed 1/4 inch in any stairway system. A worker carrying materials may not see a single uneven tread until a foot catches or misses it; consistency is a core safety feature.

Landings and vertical rise

Stairways that will not be a permanent part of the building must have a landing at every 12 feet or less of vertical rise. Each landing must be at least 30 inches in the direction of travel and extend at least 22 inches in width. These dimensions give a worker room to pause, change direction, and pass without being forced to stand on a tread at the turn. Confirm landing framing and bearing before opening the stairs for foot traffic.

Where a door or gate opens directly onto a stairway, provide a platform and arrange the door swing so it does not reduce the platform’s effective width below 20 inches. A door leaf that swings across the top step can push a worker backward onto the flight. Coordinate temporary doors, access panels, and material routes with the platform geometry. A landing that is present but blocked by tools or stock is not functioning as intended.

Handrails and stairrails

A stairway with four or more risers, or rising more than 30 inches, whichever is less, must have at least one handrail and a stairrail system along each unprotected side or edge. The standard provides height ranges and strength requirements. A handrail must be at least 30 and no more than 37 inches above the tread; where the stairrail top also serves as the handrail, its height is 36 to 37 inches. The exact measurement point is specified in the rule.

Handrails need adequate grasping surface, must not have sharp projections, and should not snag clothing. Temporary handrails require at least 3 inches of clearance from walls, stairrails, and other objects. Stairrail systems need intermediate protection such as a midrail, screen, mesh, or equivalent so openings do not exceed 19 inches. Unprotected stairway landings also need guardrails. Use the current rule rather than mixing stairway dimensions with general walking-working-surface guardrail dimensions.

Pan stairs and skeleton metal stairs

Metal pan stairs are not safe for ordinary foot traffic while the pans remain empty and are waiting for concrete or another permanent fill. Except during stairway construction, OSHA prohibits foot traffic unless the pans are temporarily fitted with wood or other solid material at least to the top edge of each pan. Replace temporary treads when wear drops them below the pan edge. The temporary insert must be secured and cover the full walking surface.

Skeleton metal stairs awaiting permanent treads or landings also need secured temporary treads and landings that cover the entire tread or landing area before normal foot traffic. Temporary treads must be solid material installed the full width and depth of the stair. An open metal frame may look climbable but can catch a boot, tool, or material. Mark and barricade stairs that are not yet ready for use.

Example: a stair flight added during fit-out

A crew installs a temporary stair to serve a 14-foot floor-to-floor rise. Because the stair is not permanent, a landing must be provided at every 12 feet or less of vertical rise. The crew confirms the landing dimensions, measures the slope, checks tread and riser uniformity, and adds the required handrail and stairrails based on the stair’s risers and total rise. If the stair is a metal pan system, each pan receives a secured solid temporary tread before other trades use it.

A delivery door opens at the upper landing. The door swing leaves only 16 inches of platform clear. That violates the cited minimum effective width. The door arrangement or landing must be corrected before the stairway is placed in service. Similar coordination issues arise when conduit, drywall carts, or stored material narrow the landing after inspection. Keep the path clear throughout the shift.

Common mistakes and exam cues

Common errors include using the permanent-building stair code for temporary construction stairs without checking OSHA, accepting uneven risers, forgetting the landing interval, and allowing workers to climb bare pan stairs. Another is installing only a handrail where an unprotected side also needs a stairrail. A temporary stairway’s use period does not remove the need for safe access.

For exam questions, identify whether the stair is temporary, count risers and calculate rise, then check slope, uniformity, landing requirements, pan infill, and rail triggers. OSHA construction requirements and building-code requirements can both apply, but they cover different contexts; use the standard named by the question and local project requirements.

Quick review

• Install stairways between 30 and 50 degrees from horizontal.
• Keep riser and tread variation within 1/4 inch.
• Temporary stairs need 30-by-22-inch minimum landings at every 12 feet or less of vertical rise.
• Four risers or a rise over 30 inches triggers handrail and stairrail requirements, whichever occurs at the lower threshold.
• Secure full-width temporary treads over pan and skeleton stairs before ordinary use.