Opening adjacent to fire barriers

[BRodgers]

I'm having a hard time finding a code section that addresses the opening perpendicular from each other. separating fire areas required three hour fire barrier so designer is requesting to install 2 separate 2 hour barriers, which I'm okay with. but it seems counter productive if there are 2 openings directly adjacent to each other right outside of the fire rated area. 707.5 seems to only address vertical continuity and doesn't talk about extending that protection beyond or walls perpendicular to each other.

 

[mtlogcabin]

Would this help? It only references 3 hr. wall assemblies. Your call as the AHJ.
104.10 Modifications.
104.11 Alternative materials, design and methods of construction and equipment.

2018 IBC
TABLE 716.1(2)
OPENING FIRE PROTECTION ASSEMBLIES, RATINGS AND MARKINGS
a. Two doors, each with a fire protection rating of 11/2 hours, installed on opposite sides of the same opening in a fire wall, shall be deemed equivalent in fire protection rating to one 3-hour fire door.

 

[BRodgers]

that was my plan for the 2 doors opening to one another. I was more curious for the overhead door to the man door perpendicular to each other immediately adjacent to where these too buildings are touching on the inside corner of the exterior walls.

 

[BRodgers]

where the rough openings into each building are less than 3' apart from each other and unprotected.

 

[mtlogcabin]

Curious, what is requiring the two hour separation?

Why is the designer creating fire areas.
Why two separate buildings?

 

[Yankee Chronicler]

Two fire barriers do not equal one fire wall. It's not two buildings unless the separation is a fire wall.

 

[BRodgers]

So a 3 hour barrier is required due to exceeding fire areas of 12000sqf. Fire barrier for s-1 is 3 hours. Trying to avoid needing sprinklers. And they are doing a separate building because they found a good deal on a kit building before thinking of the requirements. If the code is okay with 2 2hour fire walls with 2 90 minute doors equaling a 3 hour fire wall it’s logical to say it’d probably work for fire barriers too. Originally they were going to separate these but they were running into FSD issues that would requires more fire walls. They do not need fire walls because with the buildings combined they are within the allowable area with area increases.

 

[mtlogcabin]

503.1.2 Buildings on same lot.
Two or more buildings on the same lot shall be regulated as separate buildings or shall be considered as portions of one building where the building height, number of stories of each building and the aggregate building area of the buildings are within the limitations specified in Sections 504 and 506. The provisions of this code applicable to the aggregate building shall be applicable to each building.

Assume a property line between the two structures. Table 602 requires 2 hour walls for each exterior building wall with a 0 Ft. fire separation distance. However Table 601 is also applicable depending on the type of construction of the kit building and if the 2 hour wall is a bearing wall or not. Keep following the code path, check all footnotes and exceptions and you will likely end up in IBC TABLE 716.1(2) (2018 edition) which would make your design above code compliant.

 

[steveray]

If it is 2 buildings, you have an issue....If it is 2 fire areas...Not so much other than it needs to be 3 hours...