FIRE PREVENTION AND BUILDING SAFETY COMMISSION
Department of Homeland Security
Written Interpretation of the State Building Commissioner
Interpretation #: CEB-2023-13 [2020 IRC-R408.4]
Building or Fire Safety Law Interpreted
675 IAC 14-4.4 2020 Indiana Residential Code, Section R408.4 Access.
Access shall be provided to all under-floor spaces. Access openings through the floor shall be not smaller than 18 inches by 23 inches (457 mm by 610 mm). Openings through a perimeter wall shall be not less than 16 inches by 24 inches (407 mm by 610 mm). Where any portion of the through-wall access is below grade
, an areaway not less than 16 inches by 24 inches (407 mm by 610 mm) shall be provided. The bottom of the areaway shall be below the threshold of the access opening. See Section M1305.1.4 for access requirements where mechanical equipment is located under the floors.
Exception: Access may be placed under a doorway provided the step or steps that cover the opening to the crawlspace are attached to the structure at the top with a fixed pin-type hinge, so that, when the step or steps are in the raised position, passage by way of the doorway is restricted.
Does Section R408.4 of the 2020 Indiana Residential Code (IRC) require a fire-resistance rating on a crawlspace access door located in a garage floor?
Interpretation of the State Building Commissioner
No, Section R408.4 of the 2020 IRC does not require a fire-resistance rating on a crawlspace access door located in a garage floor.
Nothing in Section R408.4 of the 2020 IRC refers to fire-resistance rating of doors or panels used to provide access to crawlspaces or any other underfloor area. Such rating requirements are located elsewhere in the code, specifically Section R302.5, and are for the purpose of providing the necessary fire separation between the garage and the dwelling. Whether a garage floor access panel or door needs to be fire-resistance rated or not will depend on whether the required garage/dwelling separation is provided at the garage floor or elsewhere.
This topic was visited in Written Interpretation CEB-2020-36-2020 IRC-R302.5, albeit in the context of openings in the garage ceiling. The following excerpt from that interpretation's "rationale" statement discusses this matter. The concept is identical for openings in garage floors:
It is equally important to note that the purpose of R302.5 and its subsections is to provide the necessary protected openings between the garage and the rest of the dwelling unit, and not between the garage and its attic. . .Depending on the design of the structure, the required separation between garage and dwelling may occur at the garage ceiling, but it may also occur elsewhere instead, e.g., at the common wall between the garage and the rest of the house, provided it is designed and constructed as required by code.
Posted: 09/06/2023 by Legislative Services Agency
Composed: Dec 07,2023 9:21:33PM EST
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