Canadian Consulting Engineer

Plastic pipe penetrations

May 1, 1999
By Larry Whitty, 3M Canada Company

When a penetrating material such as electrical cables, metal pipes or ventilation duct penetrates a fire separation, Canadian building codes specify that the hole must be restored with a firestop syst...

When a penetrating material such as electrical cables, metal pipes or ventilation duct penetrates a fire separation, Canadian building codes specify that the hole must be restored with a firestop system which meets a Canadian fire test standard named ULC-S115-95. The task is made more difficult when the pipe is manufactured with a combustible material such as plastic. It is apparent that the fire must be stopped before it penetrates the fire separation and that the void left from the burned pipe be restored.

The Canadian building codes also recognize that there are differing pressures inside a building, and especially between inside and outside. Drain piping is vented to the outside of the building and when it is penetrated by fire, a direct path opens between the inside and outside. Thus the Canadian building codes have implemented a uniquely Canadian “50” Pascal pressure requirement for the ULC-S115-95 standard for testing penetration openings for firestop applications. Nicknamed “CanTest 50” this test is probably the most difficult in the world and recognizes the extreme hot and cold conditions we have in this country.

When the plastic pipe is not vented, as with a closed supply system, the Canadian test standard is also unique. Last year, Underwriters’ Laboratories of Canada (ULC) conducted a special test which was designed to indicate how different kinds of process and supply plastic pipe would perform when inserted through 4 1/2″ concrete and exposed to fire. The main objective was to observe how pipe that had been capped on both the inside and outside of the test furnace, as is allowed in the U.S., performed compared to a pipe which was capped only inside the test furnace per Canadian testing standards. This test clearly identified the Canadian system to be more stringent and safe.

To further illustrate this special condition, ULC has put many combustible pipe firestop listings into a new category. While all other firestops have an “SP” number, new plastic pipe listings are prefixed by an “SPC” number with the “C” referring to combustible. SPC listings are mandatory for all plastic pipe installations in Ontario, and for drain/waste/vent piping as per the National Building Code of Canada.

According to Tony Crimi, chief engineer at ULC, “As a result of the test conducted at ULC, the need for more rigorous testing standards has been reinforced, as has the need for greater enforcement of current codes and standards.” Crimi points out that no matter who runs the fire protection tests, they must be run correctly and according to Canadian standards.

Crimi advises all specifiers and installers of plastic pipe firestops to review the following before starting an installation:

Clearly review all listing information and compare it to the actual application.

Ensure the substrate (concrete, hollow core concrete, wood floor, one- or two-hour rated gypsum wallboard) and the type of plastic piping matches the firestop listing.

Compare the annular space around the pipe to ensure it does not exceed the maximum allowed by the firestop listing.

Check the fire rating of the separation (usually 45 minutes to two hours).

Review the need for a hose stream “FH” or a temperature “FT” rating.

Ensure the firestop system has been tested to Canadian standards, including the 50 Pa requirement for all Ontario plastic pipe applications and all drain/waste/vent applications throughout the country.

Approve all variances of the approved listing with the building official prior to installation of any firestop.

Careful attention must be paid to all firestopping issues. As the use of plastic piping increases, so must our diligence to ensure its safe installation.

Larry Whitty is project manager, 3M Specified Construction Products, London, Ontario. Tel. 1-800-3M-HELPS.


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