Simulación de porosimetría

Piping, such as for water distribution or drain, waste and vent (DWV) purposes, often penetrates combustible or noncombustible framed floor assemblies. When penetrating a fire-rated framed floor assembly, fire stops are required at the ceiling membrane and at the floor level. The specific details will be provided for the listed fire stop system chosen. For piping greater than 30 mm in diameter, the NBCC permits only noncombustible water distribution piping to penetrate a horizontal fire separation (floor assembly). There are, however, listed fire stop systems available for larger diameter combustible DWV pipes that may be acceptable to some authorities. The 30 mm diameter restriction and the horizontal restriction are removed in the Ontario Building Code. Such penetrations must be equipped with fire stops at a membrane ceiling when that ceiling forms part of a fire-rated assembly and at the floor above as shown on the left side in Figure 8.I.1.

Combustible water distribution pipe not more than 30 mm in diameter may also penetrate floor fire separations with a listed fire stop system [Ref. 3.1.9.4.(2) of NBCC

2005] in the same manner as shown on the left hand side of Figure 8.I.1. The user

should also note that the listed fire stop system selected may differ depending on whether the concrete is a topping over a fire-rated design subfloor or whether the concrete is an integral part of the fire-rated design, such as in composite designs.

Best Practice for Fire Stops for Pipe Penetrations 8-12

Figure 8.I.1:

Pipe penetration through a framed floor assembly.

If Acoustical Separation is Required…

Rated wall assembly with no penetration is one

means of good practice to provide acoustic separation for side-by-side dwelling units

The complete separating construction (including the fire stop system at any penetration through the assembly) should provide the required STC.

Note: No sound rating is needed for a fire stop system that penetrates only one surface of an insulated cavity construction. See Section 2.7.

Good Practice to Reduce Plumbing Noise:

Use resilient support for DWV and water distribution pipe, (preferably supporting vertical pipes at most rigid parts of the framing, on bottom plate of chase or wall). See additional recommendations in Figures 8.K or 8.L On the right side of Figure 8.I.1, there are two examples of DWV piping

penetrating a framed floor system. To the left of the double wall, the vertical DWV piping does not run completely through the assembly but runs horizontally through the joist space. In this case, a listed fire stop system must be provided as per its listing. This is usually at the point where the pipe enters the wall above as well as at the top plate where the pipe enters the wall below after its horizontal run. To the right of the double wall in Figure 8.I.1, the DWV pipe runs completely through the floor assembly,

penetrating both the subfloor and the ceiling. In this case, as well, a listed fire stop system must be provided at both points of penetration, as was the case for the water distribution pipe mentioned above.

Combustible sprinkler piping is permitted to penetrate a horizontal fire separation provided the fire compartments above and below are sprinklered. (See Figure 8.I.2) [Ref. 3.1.9.4.(1) of NBCC 2005] Figure 8.I.2 provides two arrangements for combustible sprinkler pipe penetrations of a framed floor assembly. On the left hand side of the figure, a sprinkler riser is located inside a non-fire-rated furred out wall and runs through the floor assembly from one sprinklered fire compartment to the one above. A listed fire stop system would be required at the ceiling level and at the floor level above. On the right hand side of the figure, the sprinkler riser runs inside a non-fire-rated partition up to a non-fire-rated ceiling installed below the fire-rated ceiling. In this case, no fire stop is required at the lower non-fire-rated ceiling but at the fire-rated ceiling and at the floor above.

Figure 8.I.2: Penetration of

combustible sprinkler piping through a framed floor assembly.

If Acoustical Separation is Required…

The complete separating construction (including the fire stop system at any penetration through the assembly) should provide the required STC.

Note: No sound rating is needed for a fire stop system that penetrates only one surface of an insulated cavity construction. See Section 2.7.

Best Practice for Fire Stops for Pipe Penetrations 8-14

Where combustible or noncombustible sprinkler piping penetrates a fire-rated ceiling membrane and leads directly to a sprinkler as shown in Figure 8.J.1, that penetration should be tightly fitted and covered with an escutcheon on the room side. Escutcheons are usually listed as part of a sprinkler system without a fire stop in the annular space. Changes to the installed sprinkler with a fire stop in the annular space between the pipe and the ceiling could impede sprinkler operation. Fire stops are often not provided at this ceiling penetration as they may potentially interfere with the

distribution pattern of the sprinkler spray should the sprinkler position move, as a result of fire stop intumescence, for example. (See Figure 8.J.1)

Figure 8.J.1:

Penetration of sprinkler piping through ceiling membrane of a fire-rated 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.

Note: No sound rating is needed for a fire stop system that penetrates only one surface of an insulated cavity construction. See Section 2.7.

Good Practice to Reduce Plumbing Noise:

Because they normally create noise only in emergencies, resilient support is not required for sprinkler pipes.

If employed, fire stops selected for this application should not deform under fire temperatures. Users should contact the manufacturer of the sprinkler to determine if fire stops can be used in this application. (See Figure 8.J.2) It is useful to note that the International Building Code specifically excludes fire stops for pipes penetrating a membrane and leading directly to sprinklers provided they are equipped with a metal escutcheon plate. (See Chapter 5 – Code Requirements for Fire Stop Installations and Sound Isolation.)

Figure 8.J.2:

Penetration of sprinkler piping through ceiling membrane of a fire-rated assembly with a fire stop.

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.

Note: No sound rating is needed for a fire stop system that penetrates only one surface of an insulated cavity construction. See Section 2.7.

Good Practice to Reduce Plumbing Noise:

Because they normally create noise only in emergencies, resilient support is not required for sprinkler pipes.

Best Practice for Fire Stops for Pipe Penetrations 8-16