"fire wall"

[augie47]

The primary local jurisdiction has always required a 4 hour rated fire wall separating occupancies in order for the the structure to be considered separate buildings allowing two services.
A new occupancy addition is being built to an existing building in a different jurisdiction and the building inspector states since it is a Class 5 construction he only requires a two hour fire wall to consider it a separate building.
Having not dealt with building codes I have always thought the 4 hr wall was a requirement. Cans some of you with knowledge of the requirement enlighten me.

 

[ramsy]

Never heard of a 4-hour fire rating requirement, I thought 2 hours was the standard.

 

[gadfly56]

Never heard of a 4-hour fire rating requirement, I thought 2 hours was the standard.

The 2-hour separation allows you to consider each space separately for fire protection purposes. Otherwise, if you have adjacent occupancies, all of them have to follow the requirements of the most restrictive occupancy. For example, an educational occupancy requires a voice evacuation system. A business occupancy may require no fire alarm at all. If they are separated by a 1-hour firewall, the business occupancy now needs a voice evac system that is common with the educational occupancy.

 

[augie47]

(revised wording of OP)
For the application of 230.2 can a separate service be installed if there is only a 2 hr wall between occupancies ??

 

[ramsy]

(revised wording of OP)
For the application of 230.2 can a separate service be installed if there is only a 2 hr wall between occupancies ??

Sounds like something a fire alarm contractor, or plan checker can help with.

 

[Joe.B]

It's going to depend on what the occupancies are. In order to use a wall to "create" two buildings it must be a "fire wall" constructed per 706. Not a "fire barrier" (707) or "fire partition" (708).

You also need to look at 508.

 

[augie47]

Thanks guys...
In my old age I am amazed at how many inspectors enforce "rules" that are based on habits and hearsay and not knowledge.
Locally I have heard for years that in order for a stricture to be considered multiple buildings a 4 hour wall was required,

 

[Joe.B]

Locally I have heard for years that in order for a stricture to be considered multiple buildings a 4 hour wall was required,

There's a lot of that. It makes sense though, a 4-hour wall will work anywhere, no need to figure out what the occupancies are.

 

[augie47]

cost be damned..huh

 

[hillbilly1]

Usually a block wall is considered a four hour rating, and extend above the roof line. I can’t remember if 8” block or 16” block must be used, but I think it is 8”. A 2 hr wall usually just goes to the deck.