another mixed use ? on sprinklers

[BSSTG]

Greetings all,

I am hearing of a possilbe project coming up. An existing F1 of about 4000 sq/ft. What is proposed is atop the F1 putting several R2 apartments. R2 has to have sprinklers for sure. What about separation? Going to T508.3.3 it states that 2 hour separation is required between the F1 and R2 if the the building in nonsprinklered. I am assuming this will apply unless they want to go back and sprinkler the F1(even thoughi it's existing) as well which would mean the entire building would be sprinklered. Therefore if the whole building is sprinklered, only a 1 hour separation would be required. Am I assessing this correctly?

There is also a possilbility that the entire building might exceed the area limitations of T503. I don't know for sure. If the entire project exceeds the allowable 9500 sq/ft for VB, they will have to sprinkler the whole place anyway to allow for the increased size of a mixed use occupancy. Right?

thanks folks

BS

 

[steveray]

Watch that horizontal fire barrier for the VB.......make sure you get the UL# and it in done properly, and that means that EVERYTHING that holds it up also has the same rating.....I think you are correct on the rating reduction...can't check right now...

 

[mtlogcabin]

Remember that is a full NFPA 13 sytem throughout the entire building

 

[Coug Dad]

Sprinklers would be required throughout the building since you are adding a Group R-2 occupancy to the fire area.

 

[brudgers]

Sprinklers would be required throughout the building since you are adding a Group R-2 occupancy to the fire area.

Yep the entire building must be sprinklered because there is a group R fire area. The system could be 13R typically.

 

[BSSTG]

OK

Got it. I was mistaken. I was thinking you could utlilize 508.3 for separated occs and get away without sprinklering the whole bldg, only the R. With that in mind, could the rules for 508.2 be applied by requiring the whole bldg to be sprinklered per NFPA 13 and negate the separation requirement as along as the area restrictions of T503 were met? Wouldn't the buidling then be considered nonseparated occupancies?

BS

 

[FM William Burns]

With others...once you add the new R its a new ball game and the entire building housing a R use is affected.

Part II question, I believe is Yes if 13 system used not just the 13R.

 

[TJacobs]

If they need an area increase they need a 13 system throughout. Otherwise they can use a 13R in the R, 13 in the F-1. 1 hour separation when sprinklered, correct.

 

[TJacobs]

Post deleted since I used wrong code section.

ops

 

[mtlogcabin]

[F] 903.3.1.1 NFPA 13 sprinkler systems.

Where the provisions of this code require that a building or portion thereof be equipped throughout with an automatic sprinkler system in accordance with this section, sprinklers shall be installed throughout in accordance with NFPA 13 except as provided in Section 903.3.1.1.1.

footnote from Table 508.4

S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

NS = Buildings not equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

It is not a sprinklered building under 508.4 unless it is a full NFPA 13 system. A 13R will not give you the reduction.

 

[steveray]

TJ....I thinjk you can still get a reduction from 2 to 1, just not from 1 to 0....differences when you are talking about construction type "protection" vs occupaccy seperations...

 

[brudgers]

If they need an area increase they need a 13 system throughout. Otherwise they can use a 13R in the R, 13 in the F-1. 1 hour separation when sprinklered, correct.

On what basis would the F1 occupancy require a full 13 system?

 

[steveray]

On what basis would the F1 occupancy require a full 13 system?

903.2.7 IBC CT shall be provided throughout all buildings with a group R fire area.....

 

[TJacobs]

TJ....I thinjk you can still get a reduction from 2 to 1, just not from 1 to 0....differences when you are talking about construction type "protection" vs occupaccy seperations...

Thanks. Actually I referred to the wrong code section. Table 601 applies to structural fire ratings, so for a VB there are none. For separated occupancies, Table 508.3.3 is used, which requires 1 hour separation with a 13 system and 2 hours without a 13 system. My mistake.

The OP could bump up the TOC to VA to get more allowable area, at which point fire area comes into play.

 

[TJacobs]

on what basis would the f1 occupancy require a full 13 system?

nfpa 13r 3.3.6, a.1.1.

(anybody know why it changes capital letters to small?)

 

[brudgers]

nfpa 13r 3.3.6, a.1.1.(anybody know why it changes capital letters to small?)

Yep and any building with cmu exterior walls and wood trusses is Type III.

 

[JBI]

Ben, the trigger for sprinklers is not the F-1, it's the proposed R occupancy.

Since the sprinklers are 'required throughout' buildings with R occupancies, the F-1 gets them also.

 

[brudgers]

Ben, the trigger for sprinklers is not the F-1, it's the proposed R occupancy. Since the sprinklers are 'required throughout' buildings with R occupancies, the F-1 gets them also.

Is it not the case that an R13 system is a sprinkler system under the IBC?

 

[permitguy]

Hell, why not shred 13 and 13R and just use 13D for everything? I mean, a sprinkler system is a sprinkler system is a sprinkler system, right?

 

[mtlogcabin]

Is it not the case that an R13 system is a sprinkler system under the IBC?

It is one of three types that is referenced under the IBC as an "automatic sprinkler system in accordance with Section 903.3.1.2". As noted above in post#10 a sprinklered building under Table 508.4 is "S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1." all other systems are not considered a sprinkler building for the purpose of reducing occupancy seperation requirements.

Can he put a 13R in the apartments and a 13 in the F-1 and be sprinklered? Yes but he can not reduce the seperation requirement from 2 to 1 hour as required by Table 508.4 because it would be considered a non-sprinklered building under that code section.

NS = Buildings not equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

 

[brudgers]

It is one of three types that is referenced under the IBC as an "automatic sprinkler system in accordance with Section 903.3.1.2". As noted above in post#10 a sprinklered building under Table 508.4 is "S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1." all other systems are not considered a sprinkler building for the purpose of reducing occupancy seperation requirements.Can he put a 13R in the apartments and a 13 in the F-1 and be sprinklered? Yes but he can not reduce the seperation requirement from 2 to 1 hour as required by Table 508.4 because it would be considered a non-sprinklered building under that code section.

NS = Buildings not equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

Two hour construction will often be less expensive than a full 13 in a wood frame building. Particularly when a full 13 will still require upgrading the existing structure to one hour.

 

[brudgers]

Hell, why not shred 13 and 13R and just use 13D for everything? I mean, a sprinkler system is a sprinkler system is a sprinkler system, right?

Where appropriate, 13D provides the level of life safety intended by the code.

 

[mtlogcabin]

Two hour construction will often be less expensive than a full 13 in a wood frame building. Particularly when a full 13 will still require upgrading the existing structure to one hour.

As an AHJ I do not have to be concerned with the cost. I just have to agree that the path you choose as a DP is code compliant

 

[permitguy]

Where appropriate, 13D provides the level of life safety intended by the code.

Alright then, find someone (besides yourself) that thinks 13R or 13D provide the appropriate level of protection for an F occupancy. Best of luck in that endeavor.