Understanding mezzanine stairs code requirements

A very common application for industrial metal stairs is access to mezzanines. These mezzanines are typically used for storage, work space, office space, or other general use conditions. A common question we get is whether or not mezzanines require IBC compliant stairs or OSHA compliant stairs. 

Mezzanine vs Equipment Platform

To answer that questions, it first helps to define a mezzanine. According to IBC, a mezzanine is an intermediate level or levels between the floor and ceiling of any story and in accordance with Section 505. Section 505.2 states that a mezzanine shall be considered a portion of the story below. So a mezzanine is considered a permanent part of the building which must comply with Chapter 10 Means of Egress, and any stairways to access the mezzanine will need to be IBC compliant.

Where some might get confused is in the difference between a mezzanine and an equipment platform. IBC defines equipment platform as an unoccupied, elevated platform used exclusively for mechanical systems or industrial process equipment, including the associated elevated walkways, stairways, alternating tread devices and ladders necessary to access the platform.

Unlike a mezzanine, an equipment platform is not considered a portion of the floor below and stairwaysalternating tread devices and ladders providing access to an equipment platform shall not serve as a part of the means of egress from the building. So stairways to equipment platforms will typically need to comply only with the OSHA stair requirements. 

Determine What Code Applies

The first question to ask is always what is the use of the structure? If it is strictly for equipment or mechanical systems, then it is likely an equipment platform. If any other use, it is a mezzanine that must have IBC compliant industrial stairs to access. These stairs are pictured below. 

Toler Mezzanine Stair (right exit)

What about non-standard, steep stairs like ships ladders, alternating tread stairs, and spiral stairs? These devices are all allowed to access mezzanines or equipment platforms under certain circumstances. If it is an equipment platform that you need to access, OSHA 1910.25(b)(8) states that spiral, ship, or alternating tread-type stairs are used only when the employer can demonstrate that it is not feasible to provide standard stairs. Having a space limitation is an allowable demonstration of feasibility for these devices. 

For access to mezzanines, IBC allows use of ships ladders, alternating tread stairs, and spiral stairs for certain types of mezzanines. The below table outlines the allowable use of each device for accessing mezzanines. 

Stair  / Ladder Type

IBC Allowable Use as Means of Egress to Mezzanine structures

Alternating Tread Stairs Section 1011.14 Alternating tread devices are limited to an element of a means of egress in buildings of Groups F, H, and S from a mezzanine not more then 250 square feet in area and that serves not more than five occupants.
Ships Ladders Not allowed under IBC as a means of egress to mezzanines.
Spiral Stairways Section 1011.10 Spiral stairways are premitted to be used as a component in the means of egress only within dwelling units or from a space not more than 250 square feet in area and serving not more than five occupants, or from technical production areas in accordance with Section 410.6 
Permanent Ladders

Section 1011.16 Permanent ladders shall not serve as a part of the means of egress from occupied spaces within a building.

Permanent ladders are permitted to provide access to specific work areas only. 

With more than 40 years in the metal stair business, the Lapeyre Stair team can help you design and manufacture industrial stairs for mezzanine and equipment platform access to meet either IBC or OSHA standards. We look forward to helping!Subscribe