Firestopping: Once an art, now a science
Until recently, veterans of the construction industry could brag of how they relied on creativity and even artistry to ensure that every detail in the construction of healthcare facilities complied with all of the life safety rules. Fire prevention, protection, and suppression code compliance many times required individual judgment in particular situations and sometimes resulted in untested and even deficient construction. This occurred despite the best of intent of the architect and building contractor, and even with the approval of the building inspector. With the complexity and congestion of mechanical/electrical wall penetrations in hospital construction, we could easily compare past applications of firestopping with mineral wool and drywall compound on wallboard to an artist's paint on his canvas. Today, the artistry of fire separation has quickly given way to an exacting science with stringent standards, specialty contractors, and advanced material technology.
The integrity of fire separations, whether they are walls or floors, is and always has been of paramount importance in hospitals. Obviously, the major purpose of fire separations is to isolate the smoke and fire from the patient who can't run down the stairs to get out! And remember, you can't use the elevators in the event of a fire. Complete separation (passive fire protection) for enough time to put out the fire (active fire protection) is key to life safety in hospitals.
Firewalls and floor assemblies have been tested and rated (in terms of how many hours or minutes they can restrain a fire) for decades by independent testing laboratories such as Underwriters Laboratories. Insurance underwriters have dictated minimum separation requirements and building codes since the Great Chicago Fire. However, in even the best-designed building, there is a myriad of fire separations with literally thousands of penetrations. It would be nearly impossible to determine which ones would really pass the test of an actual fire. After all, the fire separation assemblies were likely tested under simple conditions with no “real world” flaws. The real world of hospital construction often exists under less than ideal conditions, with high levels of infrastructure congestion, difficult access, and constructability situations leading to a potential for concealed deficiencies—unless thoroughly tested devices and techniques are employed
At the top of the list of imperfections and complexities that jeopardize the validity of the claimed fire rating of a particular assembly is the fact that the method used for sealing penetrations and joints in the past has been proven inadequate. That is, penetrations or joints sealed merely with drywall compound or mineral wool can breach in a fire situation long before the rest of the separation fails in a fire of a rated duration. This discovery, along with the growing attention given to fire safety in buildings, has led to significant advances in the technology of firestopping. But before the science of firestopping could make significant advances, the building code had to advance first
In Wisconsin, fire safety codes started to change in 1998 when the Department of Commerce began requiring tested methods and materials to seal joints and penetrations in fire-rated building elements. This led to the enormous market we see today in intumescent caulk and the many different rated sleeves for every type of wall, floor slab, and pipe or cable penetration. But until recently, these new products were universally installed by the same tradesmen who installed the penetrations or built the walls. Traditionally, training has been spotty and unregulated, which has meant more work for the building inspectors and more frustration for the construction managers trying to close up walls and ceilings on schedule.
Let us fast-forward to today. The latest development in this trend toward better fire separations is a new breed of specialty contractor: the firestop specialist. This type of contractor can assist in the design process, provide a complete bid for all types of firestopping, and furnish and install all fire separations with a Factory Mutual label documenting all aspects of the fire seal. Factory Mutual now certifies firestop contractors, requiring a high level of experience and rigorous testing. This is known as the Factory Mutual 4991 Certification and is now becoming a contractual requirement by hospital architects and owners.
CG Schmidt is building a new $56 million hospital for Wheaton Franciscan Healthcare, one of the largest integrated regional health care delivery systems in Wisconsin. We have awarded all firestopping on this project to an FM 4991-certified contractor, Hamilton Benchmark, Inc. This work category includes:
Penetration firestopping for pneumatic tube, plumbing, fire protection, HVAC, electrical, and other systems
Top-of-wall firestopping for gypsum board partitions, as well as for masonry firewalls
Perimeter firestopping at all exterior slab edges
As all healthcare facility managers know, even if fire barriers are constructed perfectly the first time, maintaining the integrity of these fire barriers during renovations, area build-outs, and even day-to-day moves and changes can be a challenge. This is of special concern, since JCAHO is becoming increasingly rigorous with its inspections to determine fire-separation integrity.
Facility managers are well advised to work with their construction managers in developing a fire-barrier–management program to become part of the facility's policies and procedures for all contractors and engineering staff working in the facility. This program should start with accurate drawings that depict all fire separations and their ratings. The plan should include a barrier access policy, an implementation checklist, the written policy and procedures on barrier integrity, specifications, and code references.
The best barrier-management program and the best life safety design and construction begin before you renovate, before you build new, and even before the schematic design for a new facility is begun. This program should use good design—one that blends the client's needs with the building code. The program should also use a good contractor—one that blends good hospital building experience with credentials and knowledge in fire-barrier construction.
We always hope the fire barriers we build are never tested, but there is comfort in knowing that if there ever is a fire, the new science of constructing and maintaining high-quality and reliable fire separations can help save lives. HD
Lou Jantzen, PE, is a Project Director with CG Schmidt, Inc., Milwaukee. For more information, phone 414.577.1177.