Yours, Mine, or Ours? Who is Responsible for the Firestopping?
by Randy G. Clark
Since I first got my start in firestopping more than eighteen years ago, I have seen many changes take place within this very young industry. The number of manufacturers having listings for firestop systems has increased more than three-fold. The model codes have gone from unclear firestopping references to specific language within a section devoted exclusively to firestopping. With these code refinements came increased enforcement by the local building officials. Architects have become much more aware of the need to provide clear and specific details of the firestop conditions needed within their building designs. Mechanical, electrical, and plumbing engineers are now automatically incorporating proper firestopping techniques, which influence the design of their individual service runs. The types of products offered were only a few, but now they include: Sealants, putties, mortars, pillows, boards, wrap strips, devices, etc. Though there have been many changes, there seems to be one persistent questions: Whose responsibility is it to do the firestopping? Before we deal with this issue, we need to review the following: What is firestopping, why do we need to firestop, and how are firestopping materials tested?
One way to look at firestopping would be to say that it is a material or a combination of materials used to re-establish the fire integrity of a rated wall or floor assembly after its rating has been compromised by the inclusion or exclusion of a penetrant. To simplify, one must maintain the time rated integrity of an assembly after any alteration. As an example, when an insulated pipe is installed through a two hour rated gypsum wall, that pipe has destroyed the original rating of the wall. If the contractor follows a tested firestop configuration and properly installs the listed firestop materials, the original rating of the wall with its penetrant is maintained.
Why do we need to firestop? First of all, firestopping is one of the requirements of the various building codes. All major building codes have at their foundation fire codes. The integrity of a building during a fire condition must be maintained in order to have a safe evacuation of its occupants. The integrity also needs to be maintained in order to provide the firefighters their best opportunity to put out the fire. Secondly, firestopping is a matter of life safety. The lives of the firefighters as well as those of the buildingâ€™s occupants could very well depend on having properly firestopped penetrations. Using a product which is part of a recognized firestop system configuration will meet the requirements of the codes.
How are firestopping materials tested? Both the industry at large and the building and code officials recognize the established test standard ASTM E814 or UL 1479, “Fire Tests of Through-Penetration Firestops.” This standard was first published in 1981 and had at its roots one of the oldest fire tests, ASTM E119, “Fire Tests of Building Construction and Materials.” ASTM E814 (UL 1479) mandates that the fire endurance of the firestop system configuration be not less than that of the fire rated assembly when tested under a minimum positive pressure and to the standard time-temperature curve. After the successful passage of the fire endurance portion of the test, the entire assembly is subjected to the erosion, impact, and cooling effects of a high pressure firemanâ€™s hose. Both the fire endurance as well as the high pressure hose portions must be successfully passed to meet the requirements of this standard.
Then whose responsibility is it to firestop? Let us examine several layers of responsibility: The architect/engineer, the local building official, the general contractor, the sub-contractor/specialty contractor, and the firestop manufacturer. It would seem that each of these entities would have a separate agenda and at times would seem to be adversarial, but when it comes to firestopping, each shares a common responsibility: Life-Safety. Let us briefly examine their responsibility and the manner in which prior planning could affect the degree of fulfillment of this responsibility.
The architect/engineer for the project is responsible for developing a concept and committing it to paper. He is also responsible for literally hundreds of building elements, not only specifying which to use, but also making sure that each will function as intended and in harmony with the others. His design and its elements must meet the local code requirements. However, the design configurations can have an impact not only on the method of firestopping, but, in turn, can have an impact on the complexity of the system and its overall cost. Let us examine some of these parameters: The selection of materials, the size of the opening, the quantity of penetrants within the opening, and the intended conditions as to which the penetrants will be subjected.
What about the selection of materials? After the architect has established a design to match the ownerâ€™s requirements, the various engineers set to work designing the specific service runs. These runs may be for electrical conduit or cables, piping for domestic water, steam or chilled water, HVAC duct work, or other services. The choice of a particular run could affect the method and materials used in firestopping and its overall cost. For example, combustible penetrants (especially various types of plastics) are usually more difficult than metallic penetrants to firestop and sometimes require the use of special collars or wraps. These collars extend beyond the diameter of the pipe, and because of their anchoring, more space is required between penetrants. In addition to complications with combustible penetrants, there are types of pipe insulation materials which are more difficult than others to firestop. Furthermore, it is important to make sure that there is sufficient annular space provided for the insulation so that an appropriate amount of the selected firestop material can be used. The annular space created will be in direct proportion to the size of hole made within the assembly and the size of the hole made can affect both the methods and materials used.
What about the size of the openings? Having too little or too much annular space can create difficulties in properly firestopping a condition. In most cases, the hole size must be planned to fit not only the penetrants, but also to fit the amount of firestop material required for the condition. Large openings within a floor may present a problem if the annular spaces created exceed four inches. Since this dimension is the average width of a human foot, most specifications will require that a plate be installed or that a material which could support the same weight as the floor be used. Since larger openings generally create large annular spaces, these larger areas present a greater surface area for the fire to react against and present, therefore, more severe conditions. One should allow for the smallest amount of annular space around the penetrants, while making sure the space provided falls within the tested configuration of the selected firestop material. This optimization could ensure minimal total cost of firestopping, while still providing a configuration which should meet with the local building officialâ€™s approval. Multiple penetrants can also contribute to difficulties.
How could the quantity of penetrants within an opening affect the proper firestopping of that opening? Some designers will utilize one large opening into which to place many penetrants. This would normally be done for simplicity, however, in most cases, individual openings would be more desirable. It is usually more cost effective to firestop a single penetrant in an opening rather than multiple penetrants. There are far more listings in the Underwriters Laboratories Fire Resistive Directory for single penetrants within a hole than for multiple penetrants within a hole. Placing multiple plastic pipes (especially large diameter DWV pipes) within the same opening could result in a condition for which there is no currently listed firestop system. Plastic pipes should always be run in individual holes allowing for ample space between the openings. Multiple penetrants, especially within a wall opening, can present a problem for the installer because of the necessity to fill the areas between the penetrants with firestopping materials. If the penetrants are too close or are too random in placement, the installer may not be able physically to place the materials into the spaces between the penetrants. This difficulty could cause great consternation and needless delays in the job. All firestop materials are expensive, and the larger opening, the greater the total cubic inches of fill material needed. Additionally, the more complex the opening, the greater the total time required to complete the installation. Since time is money, increased complexity contributes to an increased installed cost. The selection of materials, the size of the opening and the quantity of the penetrants all reflect on the conditions at the time of installation, but what about the day to day conditions of the penetration?
What about the intended conditions these configurations must endure during the life of the building? The engineers will select the appropriate service runs for the duties intended. The selection of materials will include the type and schedule of pipe, the type and size of insulation, the type and size of cables, and the size and gauge of duct. These materials have been engineered to perform within their environment and within the appropriate design limits. However, consideration must be given to the firestopping methods and materials to be used if these materials are placed within fire rated assemblies. Will the penetrants experience extreme vibration or movement? Will the penetrants experience an unusual atmosphere of high moisture, water or chemicals? Will the penetrants be exposed to elevated temperatures? These variables could affect the selection of a proper firestop configuration. In these situations as in all unusual cases, the manufacturer should be consulted for a specific recommendation.
What about the others having responsibilities for proper firestopping? The local building officials (inspectors) have the responsibility by statute to enforce the locally adopted building code requirements. The inspectors will require that the contractor furnish sufficient documentation to show that the installed firestop configuration and the products used meet with the requirements of the code for the particular assembly and penetrants. These inspectors have the ultimate responsibility to approve or disapprove any firestop system, whether it is a tested system or an engineered judgment. The general contractor is under contract with the owner to construct the project in accordance with the plans and specifications. Therefore, the general contractor has the ultimate responsibility to complete the work, even if the subcontractor (who had the original responsibility) fails to complete his individual contract. When it comes to firestopping, it is most common for the contractor making the hole to have the responsibility to fill it properly. In the last few years, there has been a growing number of specialty contractors (applicators) who concentrate in the application of firestop materials. These applicators will contract for the entire project or will only subcontract for the firestopping from the other trades on the job site. These specialty applicators will facilitate a more consistent approach to firestopping for the overall project. In fact, an increased number of specifications call for the firestopping to be done by a single contractor. Lastly, the manufacturers have the responsibility to develop and test products which will best meet the needs of a rapidly changing building industry. These products not only have to work, but should also be easy to install and be cost effective. The manufacturers also have the responsibility to furnish sufficient documentation for their products and for the configuration in which they must be installed. If there is any question about the design or use of a particular product in a specific condition, the manufacturer should be contacted. The responsibility for proper firestopping is truly a shared one.