The Fire Protection Obstacle Course: 5 Gotchas That Can Make or Break Your Project

by Mike Lehner, P.E.,

This article is part of Wood Harbinger’s newsletter series.

Fire protection system design is often viewed as an extension of mechanical engineering or a scope left up to the contractor’s discretion. In some cases, this methodology may work, but it opens up a project to unnecessary risks. You are essentially “rolling the dice.” As a Professional Mechanical Engineer as well as Professional Fire Protection Engineer, I’ve seen my fair share of sneaky requirements and complex coordination issues. As I started to write this article, it only took me about 10 minutes to come up with a list of at least 15 fire protection scenarios that could cause trouble for a project if improperly addressed or ignored. As you can see, there are many pitfalls or “gotchas” that can cause trouble.

A theme emerged from some of these “gotchas,” a common one not unique to fire protection systems and engineering, but projects as a whole. Poor communication is often the root cause of problems. Without timely communication and without asking the right questions, inconsistencies and incongruities can arise that will have to be ironed out later, often with unanticipated costs attached.

Here are five scenarios to watch out for on your next project:

Anticipating additional requirements from the Authority Having Jurisdiction, AKA the Fire Marshal

Why do you need to talk to these parties, you ask? Every jurisdiction has different requirements and potential amendments to the building code. While some are not significant, many have far-reaching implications to the fire protection scope of a project. They can range from increased sprinkler flow requirements, additional area for sprinkler riser rooms, fire department connection and hydrant requirements, and many others. Contacting the fire marshal sooner rather than later and asking relevant questions reduces the likelihood of significant changes.

Requesting the fire marshal’s amendments to the building and fire codes applicable to your project is a great place to start. They also usually provide input about system features that integrate with fire department needs, such as hydrants, fire department connections, alarm bells, and so on. If you did not check with the fire marshal early in the design process, any of these gotchas could come up during construction, when changes are much more expensive.

Addressing insurance requirements

Some insurance companies require additional fire protection measures in many commercial facilities as a means of loss prevention. The building owner receives lower rates in return for having a fire sprinkler system in the building. Buildings that don’t comply with the insurance requirements won’t receive this insurance discount.

FM Global is one insurance company that has established many detailed requirements for fire protection systems and for the buildings themselves. Their requirements for high-piled rack storage are a perfect example. While NFPA-13 (usually followed by local codes) has specific requirements with respect to sprinkler water density and areas, FM Global uses a different approach and may require additional in-rack sprinklers versus high ceiling sprinkler densities. Note that FM Global publishes their data sheets online for free.

Contacting the building owner’s insurance underwriter and asking what special requirements they have above and beyond the building code is a must-do. If you don’t, project shortcomings could be revealed during construction, which will complicate the process and add unwelcome costs.

Getting water supply data

Fire sprinkler systems require adequate water pressure in order to effectively suppress fires. The sprinkler code requires that systems be capable of discharging a minimum volume of water over a certain area, usually 1,500 square feet or more. Sprinkler flows can be anywhere from 200 gallons per minute for a simple office to more than 1,500 gallons per minute for high-piled storage applications. As such, you need to make sure the existing water mains slated for use by the fire sprinkler system have enough pressure and flow so that the system will work. Without having this information up-front, the contractor completing the full system design and construction may design the system around inadequate supply pressure. The result would be added costs, ranging from simply upsizing the sprinkler piping to providing fire pumps.

A fire flow test can provide water supply data and then a preliminary calculation can be made to assure the existing city mains can provide enough water flow and water pressure. The contractor will perform the final detailed calculations, but you need the preliminary calculations to assure there is adequate supply. In some cases, where the water pressure is low, a fire pump could be needed to supplement the water supply. Not knowing this prior to construction would result in a significant change order, as fire pumps are very costly, in the range of $500,000 or more when including ancillary costs. Ancillary costs may include fuel tanks or generators, additional floor space, and ongoing maintenance costs. Depending on the project, this could completely wipe out the project budget, disrupt the project schedule, and create lasting consequences over the life of the facility.

Determining possible areas for sprinkler drainage

Just as the fire marshals of unique jurisdictions have different requirements that must be met, the municipal utilities department in charge of water usually has specific requirements for sprinkler water discharge. Some jurisdictions require that sprinkler water be discharged to the sanitary sewer and not the storm sewer. In this scenario, the project mechanical engineer needs to provide a drain receptacle (usually a standpipe drain) to capture the sprinkler drainage.

During construction, there may be areas where the sprinkler system needs draining. If there are no drains available, it could result in additional costs and/or exposed piping to allow the system to drain. Having a fire protection engineer look at the project before bidding can help mitigate this situation.

Coordinating with the project architect

Coordinating with your internal project team players is just as important as coordinating with outside stakeholders. The project architect, for example, works to integrate all the required building systems with the overall building aesthetic. The full team benefits when the fire protection engineer anticipates visible piping issues and collaborates with the architect early in the project design to find the best solution that maintains the desired building aesthetic while meeting the fire suppression system needs. Early coordination drives effective sprinkler head placement and type/color selections; it also helps identify where soffits or other pipe routing solutions can minimize the need for exposed piping in finished areas. Coordination and collaboration between team members early on always helps avoid such problems down the line.

Up-front and thorough communication between the right project stakeholders and project disciplines is an essential component in achieving successful outcomes. It’s the key to mitigating avoidable design challenges and surprises during construction, both of which can be costly setbacks. Don’t get caught by any of these gotchas! The background knowledge and special expertise of a fire protection engineer may just save the day.