Fire Barrier Continuity

[Mech]

2009 IBC

707.5 Continuity. Fire barriers shall extend from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, slab or deck above and shall be securely attached thereto. Such fire barriers shall be continuous through concealed spaces, such as the space above a suspended ceiling. It appears that Fire Barriers must extend to the underside of the flooring material, not at the underside of a ceiling / floor assembly. Is this correct? If so, how do I run a new fire barrier to the underside of an existing wooden floor? The floor joists measure 3"x12" and are on 12" centers. The fire barriers will run both parallel with and perpendicular to the floor joists. Can the fire barrier stop at the underside of a fire rated ceiling / floor assembly?

Thanks

 

[Mech]

(repost to separate question portion)

2009 IBC

707.5 Continuity. Fire barriers shall extend from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, slab or deck above and shall be securely attached thereto. Such fire barriers shall be continuous through concealed spaces, such as the space above a suspended ceiling.

It appears that Fire Barriers must extend to the underside of the flooring material, not at the underside of a ceiling / floor assembly. Is this correct? If so, how do I run a new fire barrier to the underside of an existing wooden floor? The floor joists measure 3"x12" and are on 12" centers. The fire barriers will run both parallel with and perpendicular to the floor joists. Can the fire barrier stop at the underside of a fire rated ceiling / floor assembly?

Thanks

 

[mtlogcabin]

Can the fire barrier stop at the underside of a fire rated ceiling / floor assembly?

Yes it can provided you comply with Section 715

707.8 Joints.

Joints made in or between fire barriers, and joints made at the intersection of fire barriers with underside of a fire-resistance rated floor or roof sheathing, slab, or deck above, and the exterior vertical wall intersection shall comply with Section 715.

FIRE-RESISTANT JOINT SYSTEM. An assemblage of specific materials or products that are designed, tested and fire-resistance rated in accordance with either ASTM E 1966 or UL 2079 to resist for a prescribed period of time the passage of fire through joints made in or between fire-resistance-rated assemblies.

 

[Mech]

mtlogcabin - it appears you quoted from the 2012 IBC. This project falls under the 2009 code, which does not specify fire resistance rated flooring.

From the 2009 IBC:

707.8 Joints. Joints made in or between fire barriers, and joints made at the intersection of fire barriers with underside of the floor or roof sheathing, slab or deck above, shall comply with Section 714.

 

[mtlogcabin]

Okay no rated ceiling then the floor joist are allowed to through penetrate the wall in accordance with

2009 IBC

707.7 Penetrations.

Penetrations of fire barriers shall comply with Section 713.

713.3 Fire-resistance-rated walls.

Penetrations into or through fire walls , fire barriers , smoke barrier walls and fire partitions shall comply with Sections 713.3.1 through 713.3.3. Penetrations in smoke barrier walls shall also comply with Section 713.5.

713.3.1 Through penetrations.

Through penetrations of fire-resistance-rated walls shall comply with Section 713.3.1.1 or 713.3.1.2.

713.3.1.1 Fire-resistance-rated assemblies.

Penetrations shall be installed as tested in an approved fire-resistance-rated assembly.

713.3.1.2 Through-penetration firestop system.

Through penetrations shall be protected by an approved penetration firestop system installed as tested in accordance with ASTM E 814 or UL 1479, with a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water and shall have an F rating of not less than the required fire-resistance rating of the wall penetrated.

Personally I would allow the 2012 code to be used under alternate methods.

 

[Paul Sweet]

It varies by jurisdiction. Some jurisdictions won't allow any interruption in the fire barrier. Others allow solid fire-retardant treated wood blocking above the fire barrier. Some allow untreated wood blocking, 1 1/2" thick per hour (based on the char rate of wood).

 

[JBI]

The intent is to eliminate continuous concealed combustible spaces above the barrier. The joists become through penetrations.