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Table 601 sprinkler substitution clarification

S

sergoodo

SAWHORSE
Joined
Oct 27, 2009
Messages
305
R2

3 story

Type VA

Since 903.2.8 requires NFPA 13R sprinkler system, the TABLE 601 substitution for 1-hour is allowed with a Section 903.3.1.1 NFPA 13 sprinkler system because that system is not otherwise required. - Do you agree with this interpretation?

TABLE 601

note d. An approved automatic sprinkler system in accordance with Section 903.3.1.1 shall be allowed to be substituted for 1-hour fire-resistance-rated construction, provided such system is not otherwise required by other provisions of the code or used for an allowable area increase in accordance with Section 506.3 or an allowable height increase in accordance with Section 504.2. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.

903.2.8 Group R.

An automatic sprinkler system installed in accordance with Section 903.3 shall be provided throughout all buildings with a Group R fire area

903.3.1.2 NFPA 13R sprinkler systems. Automatic sprinkler systems in Group R occupancies up to and including four stories in height shall be permitted to be installed throughout in accordance with NFPA 13R.
 
I agree a full NFPA 13 system would be allowed to substitute for the V-A 1-hour fire resistance rating requirements in an R occupancy since an R only requires a 13R system
 
commentary 2009

Note d permits buildings of Type IIA, MIA and VA construction to use an automatic sprinkler system in compliance with NFPA 13 as an alternative to 1-hour fire-resistance-rated construction. In order to utilize the substitution, the sprinkler system must not be required for any other reason, including for increases in allowable height and area or where it is required by Section 903 based on the occupancy of a building. The sprinkler system may not be used as an alternative to the fire-resistance rating for exterior walls. This means that this exception is applicable in very limited circumstances.

sergoodoo

incase you do not have a commentary, this is 2009

http://publicecodes.cyberregs.com/icod/ibc/2009f2cc/icod_ibc_2009f2cc_6_sec001.htm

And you TO can still be a sawhorse member!!!
 
Very interesting....the R2 does REQUIRE a sprinkler system, but not necessarily the full 13......It all comes down to how you interpret "provided such system is not otherwise required by other provisions of the code"....Is it referring to the generic "sprinkler system" which is required by 903.2.8? Or specifically the 903.3.1.1 NFPA 13 system?....My gut goes with the sprinkler is required for the R2 so no substitution...Sorry MT But I am certainly staying tuned for the rest of the discussion....
 
If the code referenced 903.3.1 then I would agree. However the code references a full NFPA 13 system for any substitution, area increase, height increase are permitted with a full NFPA 13 system when other system may be required due to occupancy type.

A NFPA 13 is designed to protect life and the structure. Other NFPA 13 systems do not provide both levels of protection. They are designed more towards allowing more time for the occupants to exit the structure. Totally different design requirements.
 
Francis Vineyard said:
click open my link to the Virginia 2012 codes then scroll to the bottom for the 2015 I codes.
Click to expand...
Sorry missing the link on the Va site
 
On the example above I would calc. the allowable area

solution (a) 9,000 sf x 3 stories = 27,000 sf

solution (b) 14,000 sf x 3 stories = 42,000 sf
 
R2 table 601 1-hr rating would not be required if you limit the building to:

Type VB

NFPA 13R system

3 stories at 7,000sf=21,000sf

Area can be increased to 42,000 sf if the sprinkler system is NFPA 13 system

506.3 Automatic sprinkler system increase.

Where a building is equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the building area limitation in Table 503 is permitted to be increased by an additional 200 percent.

I interpret this as specific, I cannot get the 200% increase with a NFPA 13R sprinkler system.

I can get this height and area increase with a NFPA 13R system

504.2 Automatic sprinkler system increase.

Where a building is equipped.... For Group R buildings equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.2, the value specified in Table 503 for maximum building height is increased by 20 feet (6096 mm) and the maximum number of stories is increased by one, but shall not exceed 60 feet (18 288 mm) or four stories, respectively.

This concurs with interperting the "note d" as the substitution is allowable for the specific NFPA 13 system.
 
the area increase would be an additional 200 percent per floor w/13 (903.3.1.1)

no area increase w/13R (903.3.1.2)

it would be disadvantageous to use footnote d in this scenario for 5A w/no increase
 
Last edited by a moderator:
1. Hotel Project
2. R-2 main occupancy with A-2 (Separated).
3. VA construction
4. Fully sprinklered throughout
5. 4 Stories (Baseline is 3 stories, Sprinkler allows additional story). Taking story increase (504.2), but we are still below the allowed (baseline) height of 50', so I don't need the height increase.

Footnote 'd' allows for reduction in fire resistance rating when sprinkler system isn't otherwise required by the code OR when sprinkler is NOT used for an area or HEIGHT increase.

Since I'm not taking an area increase and since I'm not technically taking a HEIGHT increase (my building is still under 50-feet) from the Sprinkler System, it is my understanding that I could still take the 1-hr reduction in fire rating...except for exterior bearing walls.

Any other thoughts?
 
2012 IBC
ryan81 said:
1. Hotel Project
2. R-2 main occupancy with A-2 (Separated).
3. VA construction
4. Fully sprinklered throughout
5. 4 Stories (Baseline is 3 stories, Sprinkler allows additional story). Taking story increase (504.2), but we are still below the allowed (baseline) height of 50', so I don't need the height increase.

Footnote 'd' allows for reduction in fire resistance rating when sprinkler system isn't otherwise required by the code OR when sprinkler is NOT used for an area or HEIGHT increase.

Since I'm not taking an area increase and since I'm not technically taking a HEIGHT increase (my building is still under 50-feet) from the Sprinkler System, it is my understanding that I could still take the 1-hr reduction in fire rating...except for exterior bearing walls.

Any other thoughts?
Click to expand...
 
Under the 2012 edition I agree a full NFPA 13 system will allow you to take the reduction as noted in footnote "d". Normally you would only be required to provide an NFPA 13R system in an "R" occupancy. However if you want to use the trade off then you have to up the suppression system to a full NFPA 13 which is not required in an "R" occupancy

2012 IBC
d. An approved automatic sprinkler system in accordance with Section 903.3.1.1 shall be allowed to be substituted for 1-hour fire-resistance-rated construction, provided such system is not otherwise required by other provisions of the code or used for an allowable area increase in accordance with Section 506.3 or an allowable height increase in accordance with Section 504.2. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.

[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.

FYI
Footnote "d" is no longer in the codes so if you are a designer using a 9 year old code I don't think I would go that direction since you are still required to provide numerous fire protections walls and floor ceiling assemblies between the residential/sleeping units
BTW a hotel is an R-1 not an R-2 occupancy as identified in your post

1. Hotel Project
2. R-2 main occupancy with A-2 (Separated).
 
mtlogcabin said:
Under the 2012 edition I agree a full NFPA 13 system will allow you to take the reduction as noted in footnote "d". Normally you would only be required to provide an NFPA 13R system in an "R" occupancy. However if you want to use the trade off then you have to up the suppression system to a full NFPA 13 which is not required in an "R" occupancy

2012 IBC
d. An approved automatic sprinkler system in accordance with Section 903.3.1.1 shall be allowed to be substituted for 1-hour fire-resistance-rated construction, provided such system is not otherwise required by other provisions of the code or used for an allowable area increase in accordance with Section 506.3 or an allowable height increase in accordance with Section 504.2. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.

[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.

FYI
Footnote "d" is no longer in the codes so if you are a designer using a 9 year old code I don't think I would go that direction since you are still required to provide numerous fire protections walls and floor ceiling assemblies between the residential/sleeping units
BTW a hotel is an R-1 not an R-2 occupancy as identified in your post

1. Hotel Project
2. R-2 main occupancy with A-2 (Separated).
Click to expand...
mtlogcabin:

Thanks for your response. It's greatly appreciated - especially since this thread hasn't seen any activity since 2014. In my 16 year Architectural career, I've not designed a building over 2 stories, and I have never designed a residential building (My old firm just didn't really do those projects), so this is definitely a little out of my comfort zone. I have designed one, single-story type VA building, but my experience in that arena is limited. Thank you for pointing out the R-2 typo. I went back to my code review and I did have the R-1 noted, so that's good.

If you would be willing to continue helping me wrap my arms around this thing, I have a couple more questions:

(1.) Footnote 'd' allows the 1-hour reduction so long as the sprinkler system is not required by other provisions of the code. As noted, I also have an A-2 occupancy in this building. The A-2 occupancy is a dining area open to the lobby area on the main level. Section 903.2.1.2 requires an automatic sprinkler system for A-2 occupancies where the fire area has an occupant load of 100 or more people. While the calculated occupant load of the A-2 portion of the space is just barely under 100, the combined occupant load within the fire area IS over 100 people. Based on this, my interpretation is that an automatic sprinkler system is required by other provisions of the code and thus we would not be allowed to take the 1-hour reduction. Would you agree with this, or is there still some distinction in the requirement for NFPA 13 versus NFPA 13R?

(2.) Assuming I cannot take the 1-hour reduction, I've got another dilemma regarding rated assemblies. In my past experience with VA construction, I've used UL Assembly No. U348 for the exterior load bearing walls with EIFS facade, however - I was not able to find a tested wood truss roof assembly where rigid insulation is above the roof deck. I had to work with the building official in that project's jurisdiction to come up with an assembly that they would accept. I know this is going beyond my code question, but do you have any thoughts on 1-hr assemblies using wood trusses with rigid insulation above the roof deck and batt insulation below it?

Again - Thank you kindly!

~Ryan
 
It's hard to see what's being gained here. 420 still applies and 1 hour unit separations are required. This is still technically a VA building since they took the VA story increase, so the exceptions for supporting construction in 708 and 711 for IIB and VB buildings don't apply. Since 1 hour separations and supporting construction are required, you essentially have a 1 hour VA structure anyway. It's no wonder this footnote disappeared since you end up with a fully sprinklered building that can't take advantage of any sprinkler allowances (corridors, height, area, etc.) except for a 1 hour reduction in table 601.

Back in 2012 height and stories were in the same table, and I think the intent was to view them as a package in this context and not allow the story increase. I confirmed that with ICC staff back then because of this section for what it's worth. I'm glad this one is gone.
 
tod13511 said:
It's hard to see what's being gained here. 420 still applies and 1 hour unit separations are required. This is still technically a VA building since they took the VA story increase, so the exceptions for supporting construction in 708 and 711 for IIB and VB buildings don't apply. Since 1 hour separations and supporting construction are required, you essentially have a 1 hour VA structure anyway. It's no wonder this footnote disappeared since you end up with a fully sprinklered building that can't take advantage of any sprinkler allowances (corridors, height, area, etc.) except for a 1 hour reduction in table 601.

Back in 2012 height and stories were in the same table, and I think the intent was to view them as a package in this context and not allow the story increase. I confirmed that with ICC staff back then because of this section for what it's worth. I'm glad this one is gone.
Click to expand...


Doesn’t the R. Also Require a fire sprinkler??
 
tod13511 said:
It's hard to see what's being gained here. 420 still applies and 1 hour unit separations are required. This is still technically a VA building since they took the VA story increase, so the exceptions for supporting construction in 708 and 711 for IIB and VB buildings don't apply. Since 1 hour separations and supporting construction are required, you essentially have a 1 hour VA structure anyway. It's no wonder this footnote disappeared since you end up with a fully sprinklered building that can't take advantage of any sprinkler allowances (corridors, height, area, etc.) except for a 1 hour reduction in table 601.

Back in 2012 height and stories were in the same table, and I think the intent was to view them as a package in this context and not allow the story increase. I confirmed that with ICC staff back then because of this section for what it's worth. I'm glad this one is gone.
Click to expand...
I agree that there isn't a lot to be gained since (as you and mtlogcabin pointed out) the partitions between rooms and corridor as well as the floor between rooms need to be rated already and the table 601 reduction does not apply to exterior walls. It would appear that the reduction would only really get us out of providing the 1-hour rating for the roof. Whether or not there is much to be gained, and however antiquated portions of the 2012 IBC may be, I'm trying to be knowledgeable with respect to the applicable code and be able to justify my design decisions with the Owner if/when they are questioned.
 
The R requires a 13R suppression in order to use footnote "d" you must use a full NFPA 13 system through out the entire building.
I agree with tod13511 I do not see an advantage in trying to use this exception
 
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