Método Monte Carlo

Note: Many of the illustrations and much of the text in this Chapter have been adapted from Reference 8-1.

The examples shown in this Chapter represent various means of achieving fire compartment continuity with fire stops. There are other fire stop systems that may serve this purpose. For reasons of brevity, these other solutions have not been illustrated.

This Chapter will provide information on best practices for fire stops for pipe penetrations through horizontal and vertical fire separations. Prior to addressing the details of best practice, it is first necessary to understand the types of fire separations that may be penetrated and thus require fire stops. The fire stops shown in this Chapter are for illustrative purposes only. There are a number of listed fire stop systems

available to address most penetrations in fire separations. Care should be taken to select an appropriate fire stop system that meets the requirements of the fire separation being penetrated, the penetrating item, and the size of the opening.

A simplified diagram of a building over a parking garage is shown in Figure 8.A. For illustration purposes only, a noncombustible piping system is shown on the left side of the figure and a combustible piping system on the right. For both systems, pipe penetrations consist of horizontal penetrations through vertical fire separations (walls) and vertical penetrations through horizontal fire separations (floor and roof-ceiling assemblies), including those above a parking garage.

There are some cases where the NBCC allows the wall between a public corridor and the adjacent suites not to be constructed as a fire separation [Ref. 3.3.1.4. of the NBCC 2005]. In these cases, penetrations in the wall between the public corridor and the suites in Figure 8.A would not require fire stops.

With respect to fire stops, pipe penetrations of fire separations may be addressed in a number of ways depending on whether the pipes are combustible or noncombustible. Another issue relates to insulation around pipes (not part of the fire stop system), which needs to be addressed to obtain a proper seal for the fire stop. The combustible/noncombustible pipe issue has traditionally been considered by users to be more important in dictating which fire stop to use, however, the other factors, in

combination with the type of pipe, may ultimately dictate the final selection for fire stops due to their influence on installed performance.

Best Practice for Fire Stops for Pipe Penetrations 8-2

Figure 8.A:

Apartment building over a parking garage showing typical penetrations of combustible and noncombustible piping through rated fire separations. Note that the concrete floor between suites and garage, and walls separating the suites along each corridor may also be fire- rated assemblies in which listed fire stop systems might be required. (See text for need for fire separations for public corridor walls.)

Combustible Vacuum System Piping – While much of the discussion in this Chapter relates to combustible drain, waste and vent (DWV) piping, it is important to realize that best practice recommendations for combustible DWV piping are equally applicable to combustible vacuum system piping. All vacuum system piping must be equipped with fire stops where it penetrates a fire-rated assembly or a membrane

forming part of a fire separation. As well, fire stops for combustible vacuum system piping must be tested using the 50 Pa pressure differential requirement [Ref: 9.10.9.6.(9) of NBCC 2005].

Insulated Pipe Penetrations – There are situations where a pipe penetrating a fire separation must be insulated for thermal control reasons. This is not to be confused with insulation to achieve an FT rating for a listed fire stop system. In the former situation, fire stops must be designed to account for the impact of the fire stop on the insulation around the pipe. Fire stops for such insulated pipes are currently available for both noncombustible and combustible pipes. Different arrangements for fire stops are required for different types of pipe insulation and pipe materials. Specific listed fire stop systems should be used to account for these variables. The user should select a listed fire stop system appropriate for the type of pipe insulation and the type of pipe being used.

Figures 8.B.1 and 8.B.2 illustrate noncombustible and combustible pipe

penetrations with pipe insulations. In Figure 8.B.1, the fire stop must be able to seal the opening either at the outer surface of the insulation or at the noncombustible pipe if the insulation can be damaged by the fire. In Figure 8.B.2, the fire stop must be able to seal the opening in such a way that the void created by the fire-damaged combustible pipe is also sealed.

Best Practice for Fire Stops for Pipe Penetrations 8-4

Figure 8.B.2:

Insulated combustible pipe penetration through a fire- rated floor assembly

If Acoustical Separation is Required…

The complete floor/ceiling construction (including the fire stop system at any penetration through the assembly) should provide the required STC between occupancies.

Construction Issues – Users should be aware that listed fire stop systems are approved for specific types of construction (e.g., monolithic concrete, framed wood floors) and that they may not be interchangeable from one construction type to another. Users should also be aware that the installation of appropriate listed fire stop systems for pipe penetrations involves detailed preparation for such issues as coring, sleeving, annular spacing and angular penetrations. These issues should be discussed and resolved at a meeting held prior to the installation of the fire stops. The manufacturers’ literature and the listing documentation should be consulted.

Fire-Rated Walls and Non-Fire-Rated Walls – In examining Figure 8.A, a user can see that the vertical runs of pipe inside the suites penetrate horizontal fire

separations. Depending on the design, these pipes may be located inside a fire-rated wall (such as a wall dividing one suite from another) or inside a non-fire-rated wall. Users must be aware that some listed fire stop systems for pipe penetrations of floors require that the fire stop be located inside a fire-rated wall. (The listing will indicate the extent of fire resistance.) To be effective, then, the listed fire stop system needs to be inside a fire-rated wall. Otherwise, a listed fire stop system not requiring a fire-rated wall must be used.

Compatibility of Fire Stops and Plastic Pipes – Certain CPVC pipes used for sprinkler systems or water distribution may be damaged by plasticizers, such as phthalates, used in some fire stops with the result that the pipe will eventually rupture.

Hot water pipes are particularly susceptible to such damage, but cold water pipes will also fail over time. Users should consult the fire stop and pipe manufacturers’ technical literature to ensure that the listed fire stop system chosen is compatible with the CPVC pipes in the building.