SPRINKLERS + ALARMS
The Oops Factor
Learning from mistakes in the design and installation of fire protection systems
NFPA Journal®, November/December 2011
By William E. Koffel, P.E., FSPE
In the early 1980s, shortly after I had graduated from college and was working as a fire protection engineer with the Maryland State Fire Marshal’s Office, I reviewed a set of drawings and specifications for an automatic sprinkler system. The project was fairly simple: the sprinkler protection was for a five-story, multiple-occupancy building, with most of it occupied by a hotel. There was little to indicate that the project was exceptional in any way, or that I would continue to reference it throughout my professional career.
Plan review comments were generated for this “simple” project and incorporated into a four-page plan review letter that was sent to the project’s registered engineer. Not long after, when he’d received the letter, the engineer called me with a question. He asked me, “What is this NFPA 13 you’re referring to?”
It was easily the most alarming moment in the project’s review and comment resolution process. Unfortunately, I was too inexperienced and naïve to do the proper thing, which would’ve been to report him to the State Board for Professional Engineers for not even knowing the applicable criteria for designing the system. Instead, I explained to him that NFPA 13, Installation of Sprinkler Systems, was the standard used to design and install sprinkler systems in the state of Maryland. The project was eventually built, but not before a sprinkler contractor was brought in to assist with the preparation of the drawing. The result was a 25 percent increase in the number of sprinklers to be installed, in compliance with the requirements of NFPA 13.
Sometimes the best lessons are to be found in the mistakes of others, and fire protection projects are no exception. It is not my intent to cast blame or to discredit any particular shareholder that might be involved in the design of fire protection systems, whether they’re engineers, technicians, designers, contractors, or some other professional designation. What is essential is that the people doing the design or installation work know the applicable criteria for those systems and are qualified to do that work — what the codes typically refer to as “qualified individuals.” There is no job title that assures someone has this knowledge, but whoever does it needs to be able to positively demonstrate that their design and installation work meets all the requirements of the jurisdiction.
Qualifications of the designer
The example of the engineer and NFPA 13 clearly demonstrates the need for a project to be designed by people who are knowledgeable in such systems, including being able to identify the applicable design and installation criteria. This is especially timely, since there has been an ongoing discussion within the fire protection community as to whether the design of fire protection systems is an engineering activity or if the design can be done by technicians who work for an installing contractor. While some NFPA standards require that designers be qualified, the standards do not contain a specific means by which one is determined to be qualified. Instead, this is typically left to the appropriate state or local qualifications board.
There are also examples of projects where problems have occurred when the systems were designed by contractors. An example occurred recently in a municipality where it is well documented that the water supply has limited pressure. At least one sprinkler contractor took advantage of the situation; seeing that the construction documents did not provide water supply data, the contractor bid an installation using extended coverage sprinklers, despite knowing that the water supply pressure would not be adequate. Once awarded the contract, the contractor came back and requested a change order stating that there was not enough pressure to use extended coverage sprinklers and that more sprinklers would be required, which meant a higher fee for the work.
In another instance several years ago, a hospital retained a fire alarm contractor, the same contractor who had been doing work in the facility, to design and install a replacement fire alarm system. Prior to awarding the installation contract, the hospital retained the services of a fire protection engineer to review the contractor’s design. The engineer’s review occurred prior to the preparation of shop drawings that would have been submitted to the authority having jurisdiction (AHJ) for review. The engineer reviewed the design documents and noted numerous examples of initiating devices, primarily smoke detectors, that were not required, while other smoke detectors required by the applicable code were not shown. Had the contract been awarded for the installation of the system based on those design documents and these issues had been identified during the review by the AHJ, most likely a discussion regarding change orders would have occurred, resulting in increased costs to the hospital.
Considering the user’s needs
The engineering firm that reviewed the initial design documents for the hospital fire alarm project was subsequently retained to prepare construction documents to be bid by multiple fire alarm contractors. In addition to identifying the applicable code requirements, the engineer sought additional input into the design of the fire alarm system.
A survey was conducted of various stakeholders in the project, including hospital administration, nursing staff, and maintenance personnel. During a discussion of the survey results, particular attention was focused on smoke detectors in patient sleeping rooms. Hospital administration was adamant that the minimum performance required by the applicable code, that the detectors could initiate the nurse call system, was not acceptable. They felt this put too much responsibility on the nursing staff to initiate the emergency procedures. The engineer advised the stakeholders as to the rationale behind the code requirement, which was to minimize the impact of nuisance alarms. The engineer was directed to design a fire alarm system that would minimize nuisance alarms but would also automatically activate alarm notification appliances as well as the local fire department. The goal was successfully met using two alarm points for the smoke detector; the lower sensitivity activated the nurse call system, and the second alarm point activated the occupant notification and emergency forces notification.
Not all problems end up working out in the user’s favor, of course. A need that is often overlooked is the ability for the user to properly inspect, test, and maintain the system. A commonly referenced example is the use of spot smoke detectors at the top of atriums — a problem referred to in many NFPA seminars on the requirement of accessibility for the inspection, testing, and maintenance of fire protection systems. Inaccessible sprinkler control valves, fire pump test headers that are installed inside a mechanical equipment room instead of on an outside wall, and main drain assemblies that are not piped to the outside or to an acceptable drain are other common problems. Although some of these are addressed by the appropriate reference standards, others are not, and are at the discretion of the designer.
System installation
During the installation of fire protection systems, issues can arise over who is responsible for installing various system components. Who installs the duct smoke detectors, the waterflow switches, and valve supervisory switches? A general contractor once called me asking for assistance in resolving a dispute over who was to connect the conductors to the fire alarm devices. The contract documents did not specify who was to make the connections, and the general contractor was advised that it was his issue to resolve — and that the connections would have to be made prior to requesting someone to witness the acceptance test.
Several years ago a fire occurred in a three-story building undergoing rehabilitation. Part of the project involved providing automatic sprinkler protection throughout the building. The fire occurred in the building just prior to final occupancy. The sprinkler system failed to control the fire because the riser was not connected to the water supply. The design included a fire pump to meet the system demand for the standpipe system. The pump had not been installed because a part was still needed, meaning there was no functional automatic water supply to the system. However, the municipal water supply system was adequate to supply the sprinkler system, meaning a bypass should have been provided for the pump. Had the pump bypass been installed and functional, most likely the sprinkler system would have controlled the fire and there would have only been a slight delay in final occupancy of the building. Instead, the building suffered major damage and substantial delays before it could be occupied. How could this happen? Who was looking out for the owner during the installation of this system?
Proper commissioning of fire protection systems is essential and provides another opportunity for mistakes that have been made to be caught and addressed. The AHJ is often involved during system commissioning, but it must be understood that their responsibility is to verify that the system is installed in accordance with applicable codes and standards. The AHJ owes no specific duty to the owner, nor are they responsible for verifying that all the owner’s needs are met.
Several years ago a relatively new retail store suffered a major loss when the automatic sprinkler system failed to control a fire. Post-fire investigation discovered that the valve at the point of connection to the public main was closed. Some parties speculated that the valve had never been opened. It was later discovered that the main drain test results shown on the Contractor’s Certificate were not valid. Not only did the contractor misrepresent the test data, the third-party inspector — in this case an engineering firm — required to observe the test being performed also failed to identify the invalid results. The problem was further compounded by the fact that periodic main drain tests were not performed.
The good news is that successful design and installation of fire protection systems far outnumber the problem projects. With proper planning, design, installation, and commissioning by qualified individuals, the reliability of fire protection systems is enhanced, and owners are more satisfied, and safer, with the systems. Even so, it’s worth reflecting on the mistakes we encounter to help all of us be more vigilant with the systems and features that keep people and buildings safe.
William E. Koffel, P.E., FSFPE, is president of Koffel Associates, Inc. in Columbia, Maryland.