Regulations, Codes & Standards Q&A: Four-inch rule

Q: I just would like to confirm: When you say a four-inch projection is allowed into the corridor is that for one side of the corridor or is that for a total of both sides cannot exceed four inches?

A: I would say that is for each individual side of a corridor. So, each side of the corridor is allowed a four-inch projection. The reason I say that is the limit on a projection into the corridor is to prevent a sight-impaired person from running into an object while egressing. Since most corridors are wider that the largest human, the four-inch restriction is based on individual sides of the corridor. 

Brad Keyes, CHSP, is the owner of KEYES Life Safety Compliance, and his expertise is in the management of the Life Safety Program, including the Environment of Care and Emergency Management programs.