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1.24.19 – SSI – Shane Clary

Fire expert Shane Clary shares exactly what information must be included on shop drawings in order to meet NFPA 72 standards.

Hello from Stillwater, Okla., home of Oklahoma State University, where I’m taking a course through the Department of Fire Protection & Safety Engineering Technology.

While “Hydraulic Calculations of Automatic Sprinkler Systems” is not typically a course someone in the fire alarm industry would take, a fundamental understanding of sprinkler system hydraulics should be obtained if one is also performing sprinkler inspection and testing. I’ve written several articles on this and NFPA 25, “Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems.”

Depending on the state in which you operate, a fire protection contractor’s license may be required to provide sprinkler inspection and testing. An understanding of hydraulics would be necessary for the exam.

Oklahoma State offers continuing education classes, including online, on various fire protection topics; check out fire.ceat.okstate.edu for information.

Keep ‘Where Applicable’ in Mind for Checklist

First, we can all agree that 72 is a minimum standard, just as the building and fire codes that are used are minimum codes, and more can be required.

But I’ve noticed a few requirements that go beyond being either reasonable or providing any additional level of protection to the occupants of the building, or to firefighters who may be within a building during a fire or other emergency. These I won’t discuss but rather focus on what 72 addresses.

While the 2019 edition of 72 has been released, for our purposes let’s reference the 2016 edition that’s already widely adopted. The requirements for shop drawings are found within Section 7.4, Shop Drawings, which is in Chapter 7, Documentation.

The basic information that is required on all plans is:

  1. Name of protected premises, owner, and occupant (where applicable)
  2.  Name of installer or contractor
  3. Location of protected premises
  4. Device legend and symbols in accordance with NFPA 170, or other symbols acceptable to the authority having jurisdiction
  5. Date of issue and any revision dates

This is followed by 7.4.5, which notes, Floor plan drawings shall be drawn to an indicated scale and shall include the following information, where applicable for the particular system:

  1. Floor or level identification
  2. Point of compass (indication of north)
  3. Graphic scale
  4. All walls and doors
  5. All partitions extending to within 15% of the ceiling height (where applicable and when known)
  6. Room and area descriptions
  7. System devices/component locations
  8. Locations of fire alarm primary power disconnecting means
  9. Locations of monitor/control interfaces to other systems
  10. System riser locations
  11. Type and number of system components/devices on each circuit, on each floor or level
  12. Type and quantity of conductors and conduit (if used) for each circuit
  13. Identification of any ceiling over 10 feet in height where automatic fire detection is being proposed
  14. Details of ceiling geometries, including beams and solid joists, where automatic fire detection is being proposed
  15. Where known, acoustic properties of spaces

Without question, many of these items should be on every shop drawing that is submitted. But note the phrase “where applicable.” In addition to 7.4.5, the designer of a system needs to address paragraphs 7.4.6, 7.4.7, 7.4.8, 7.4.9 and 7.4.10.

Is the photometrics of a strobe required to indicate through a descending scale of hatching where the observable candela output decreases each 5cd?

These and other such requirements only add costs to a system with no real benefit. Unless I have detectors located within ceilings that go beyond flat and smooth, ceiling details should not be required.

As the plans are to be to scale, the locations of the strobes can be verified that they will meet the prescriptive requirements of Chapter 18. Audibility can be verified during the final inspection of a system.

Drawings that are produced in accordance with Chapter 7 for a prescriptive system should and do provide an adequate picture of the system that is to be installed within a protected property.