MeyerFire
  • Blog
  • Forum
  • THE TOOLKIT
    • SUBMIT AN IDEA
    • BACKFLOW DATABASE*
    • CLEAN AGENT ESTIMATOR*
    • CLOUD CEILING CALCULATOR
    • DOMESTIC DEMAND*
    • FIRE FLOW CALCULATOR*
    • FIRE PUMP ANALYZER*
    • FIRE PUMP DATABASE*
    • FRICTION LOSS CALCULATOR
    • HANGER SPACER*
    • IBC TRANSLATOR*
    • K-FACTOR SELECTOR*
    • NFPA 13 EDITION TRANSLATOR ('19 ONLY)
    • NFPA 13 EDITION TRANSLATOR ('99-'22)*
    • LIQUIDS ANALYZER*
    • OBSTRUCTION CALCULATOR
    • OBSTRUCTIONS AGAINST WALL*
    • PLUMBING FIXTURE COUNTS
    • QUICK RESPONSE AREA REDUCTION
    • REMOTE AREA ANALYZER*
    • SPRINKLER DATABASE*
    • SPRINKLER FLOW*
    • SYSTEM ESTIMATOR*
    • TEST & DRAIN CALCULATOR
    • THRUST BLOCK CALCULATOR
    • TRAPEZE CALCULATOR
    • UNIT CONVERTER
    • VOLUME & COMPRESSOR CALCULATOR
    • WATER STORAGE*
    • WATER SUPPLY (US)
    • WATER SUPPLY (METRIC)
  • UNIVERSITY
    • JOIN
    • CATALOG
    • CONTENT LIBRARY
    • [THE ALL-NEW SITE]
  • PE Exam
    • PE Forum & Errata
    • PE Store
    • PE Tools
    • PE Prep Series
    • PE 100-Day Marathon
  • LOGIN
  • PRICING
    • SOFTWARE & TRAINING
    • STORE
  • OUR CAUSE
    • ABOUT MEYERFIRE
    • BECOME AN INSTRUCTOR
    • HELP/SUPPORT
Picture

Sprinklers Req'd in Concealed Wood Truss Space?

10/27/2022

11 Comments

 
I am designing a fire sprinkler system for a 5-story residential apartment building.

The building is Type V wood truss construction with 16" open web wood trusses.

The floor/ceiling assembly is a one-hour fire-resistance-rated construction (UL listed). Sheetrock is attached directly to the bottom of the joists with wood subfloor on top. The ceiling is inaccessible (concealed).

The question of sprinkler above the ceiling has come up. I don't see a need for them. There is 6" sound batting above the ceiling.

The Fire Marshal does not allow NFPA 13R design. It an NFPA 13 design.

Is this space required to be protected?

Any input would be helpful, thanks in advance.

​​​​​​​​​​​​​​​​​​​​​​​​​Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
11 Comments
Paul Pinigis
10/27/2022 08:11:33 am

What do you mean by "the Fire Marshal does not allow NFPA 13R"? Are you saying there is a local ordinance prohibiting 13R systems, or that 13R doesn't apply because it's a 5 story building?

Reply
Todd E Wyatt
10/27/2022 08:32:36 am

The Fire Marshal is correct in that this Group R-2 (Apartments) Occupancy Classification project is required to be protected by an automatic sprinkler system (ASPS) meeting NFPA 13 and not NFPA 13R since it is (5) stories. 2021 IBC 903.3.1.2 permits Group R buildings to be protected by a NFPA 13R ASPS if it is 4 stories or less.

The AHJ (e.g. Fire Marshal) is only permitted to interpret and enforce the adopted Codes and Standards .... AHJs are not permitted to "disallow" aspects of the design based on personal preference, however.

Reply
Paul Pinigis
10/27/2022 08:24:43 am

Given that this is an NFPA 13 system, and these are combustible concealed spaces, you must meet one of the exceptions in 9.2.1 to omit sprinklers. Be careful applying this, because you have wood trusses, not joists or composite joists.

Reply
James Phifer
10/27/2022 09:00:48 am

I agree with everyone above. unless you fill that space with insulation, it appears you have a combustible concealed space that would require sprinkler protection.

Reply
Danefre
10/27/2022 09:16:10 am

You didn't mention if this is podium construction - 5 story is NFPA 13.

A bit confused on the construction. You mention trusses and floor/ceiling joists so i'm assuming typical Type V.

See the provisions NFPA 13 (2013) 8.15.1.2. More information is needed such as joist depth, solid vs composite joists, "fire stopping" and whether the entire space is filled with non-comb insulation. Also see manufacturer's data sheet for combustible concealed sprinklers. Omission of sprinklers may trigger a remote area increase per 11.2.3.1.4. You can't increase the area in order to omit sprinklers.

Is the top floor open to the trusses or is there an "attic"? Be wary of 8.6.2.2.1(a) (2013ed.). There are spacing limitations for combustible unobstructed with members 3 ft or less O.C. Also sloped ceiling requirements come into play.

Reply
Jesse
10/27/2022 09:24:42 am

Sounds like the FM is right in requiring full 13 design. These are combustible concealed spaces. I'd consider having the GC fill these with non-combustible insulation.

Reply
schulman
10/27/2022 10:03:45 am

the insulation in the design was likely only specified for meeting the R-Value requirements ... energy code .. mechanical code. ... sounds like you have to inform them that they also have to meet the fire protection codes and do what all these smart people have suggested and fill the entire cavity with insulation.

Reply
Mike
10/27/2022 01:03:45 pm

Yes they are required

Reply
Alex
10/27/2022 03:36:34 pm

Hi,

late to the game here today. Echoing what was said above regarding NFPA 13R and the number of stories you mentioned.

Based on the description, protection will be required. Worth while to review alternate options to save money (filling the voids)

Thanks,
Alex

Reply
Dan Wilder
10/28/2022 08:13:30 am

Here is a good chart to let you know what will be required for the 13 system along with the above info for allowable omission (with tradeoffs) and calc impacts as it goes much further than just the attic space.

https://www.meyerfire.com/blog/summary-of-differences-in-nfpa-13-13r-13d

Reply
John Gallagher
11/2/2022 10:43:27 am

Be sure to specify the correct sprinkler heads for the combustible concealed space, especially if you are using CPVC piping in that area.

Reply



Leave a Reply.

    SUBMIT A QUESTION
    Picture
    Why Sponsor?

    ALL-ACCESS

    Picture
    GET ALL OUR TOOLS

    SUBSCRIBE

    Subscribe and learn something new each day:
    I'm Interested In:

    COMMUNITY

    Top ​October '23 Contributors
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    SEE LEADERBOARD

    YOUR POST

    SUBMIT A QUESTION

    PE EXAM

    Get 100 Days of Free Sample Questions right to you!
    SIGN ME UP!

    FILTERS

    All
    A1171
    ABA
    ADA
    ASCE 7
    ASME A17.1
    ASTM E1354
    Blog Thread
    Daily Discussion
    Design-documents
    EN 12845
    Explosion Protection
    Explosion-protection-prevention
    Fire Detection And Alarm Systems
    Fire Dynamics
    Flammable And Combustible Liquids
    Flammable-combustible-liquids
    FM Global
    Human-behavior
    IBC
    ICC 500
    IFC
    IMC
    IPC
    IRC
    ISO
    Means Of Egress
    NBC
    NFPA 1
    NFPA 10
    NFPA 101
    NFPA 11
    NFPA 110
    NFPA 1142
    NFPA 1221
    NFPA 13
    NFPA 13D
    NFPA 13R
    NFPA 14
    NFPA 15
    NFPA 16
    NFPA 17A
    NFPA 20
    NFPA 2001
    NFPA 214
    NFPA 22
    NFPA 220
    NFPA 24
    NFPA 241
    NFPA 25
    NFPA 291
    NFPA 30
    NFPA 30B
    NFPA 33
    NFPA 400
    NFPA 409
    NFPA 415
    NFPA 495
    NFPA 497
    NFPA 5000
    NFPA 502
    NFPA 54
    NFPA 55
    NFPA 654
    NFPA 68
    NFPA 70
    NFPA 701
    NFPA 72
    NFPA 75
    NFPA 770
    NFPA 82
    NFPA 855
    NFPA 90A
    NFPA 92
    NFPA 96
    NICET
    OBC
    Passive Building Systems
    PE Prep Guide
    PE Prep Series
    PE Sample Problems
    Poll
    Smoke Management
    Special Hazard Systems
    UFC 3-600-01
    UFC 4-021-01
    UPC
    Updates
    Water Based Fire Suppression
    Weekly Exams


    ARCHIVES

    November 2023
    October 2023
    September 2023
    August 2023
    July 2023
    June 2023
    May 2023
    April 2023
    March 2023
    February 2023
    January 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    October 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    November 2016
    October 2016
    July 2016
    June 2016


    PE PREP SERIES

    Fire Protection PE Exam Prep
    SEE LEADERBOARD

    RSS Feed

Picture
​Home
Our Cause
The Blog
The Forum
PE Exam Prep
The Toolkit

MeyerFire University
​Pricing
Login
​Support
Contact Us
Picture

MeyerFire.com is a startup community built to help fire protection professionals shine.
Our goal is to improve fire protection practices worldwide. We promote the industry by creating helpful tools and resources, and by bringing together industry professionals to share their expertise.

​MeyerFire, LLC is a NICET Recognized Training Provider and International Code Council Preferred Education Provider.

All text, images, and media ​Copyright © 2023 MeyerFire, LLC

We respect your privacy and personal data. See our Privacy Policy and Terms of Service. 
The views, opinions, and information found on this site represent solely the author and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence.

Discussions are solely for the purpose of peer review and the exchange of ideas. All comments are reviewed. Comments which do not contribute, are not relevant, are spam, or are disrespectful in nature may be removed. Information presented and opinions expressed should not be relied upon as a replacement for consulting services. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a small commission for orders placed elsewhere.

  • Blog
  • Forum
  • THE TOOLKIT
    • SUBMIT AN IDEA
    • BACKFLOW DATABASE*
    • CLEAN AGENT ESTIMATOR*
    • CLOUD CEILING CALCULATOR
    • DOMESTIC DEMAND*
    • FIRE FLOW CALCULATOR*
    • FIRE PUMP ANALYZER*
    • FIRE PUMP DATABASE*
    • FRICTION LOSS CALCULATOR
    • HANGER SPACER*
    • IBC TRANSLATOR*
    • K-FACTOR SELECTOR*
    • NFPA 13 EDITION TRANSLATOR ('19 ONLY)
    • NFPA 13 EDITION TRANSLATOR ('99-'22)*
    • LIQUIDS ANALYZER*
    • OBSTRUCTION CALCULATOR
    • OBSTRUCTIONS AGAINST WALL*
    • PLUMBING FIXTURE COUNTS
    • QUICK RESPONSE AREA REDUCTION
    • REMOTE AREA ANALYZER*
    • SPRINKLER DATABASE*
    • SPRINKLER FLOW*
    • SYSTEM ESTIMATOR*
    • TEST & DRAIN CALCULATOR
    • THRUST BLOCK CALCULATOR
    • TRAPEZE CALCULATOR
    • UNIT CONVERTER
    • VOLUME & COMPRESSOR CALCULATOR
    • WATER STORAGE*
    • WATER SUPPLY (US)
    • WATER SUPPLY (METRIC)
  • UNIVERSITY
    • JOIN
    • CATALOG
    • CONTENT LIBRARY
    • [THE ALL-NEW SITE]
  • PE Exam
    • PE Forum & Errata
    • PE Store
    • PE Tools
    • PE Prep Series
    • PE 100-Day Marathon
  • LOGIN
  • PRICING
    • SOFTWARE & TRAINING
    • STORE
  • OUR CAUSE
    • ABOUT MEYERFIRE
    • BECOME AN INSTRUCTOR
    • HELP/SUPPORT