The following is a series of pictures depicting a typical fire test, in this case for a firestop, which led to an active fire-resistance rating, backed up by active product certification. A copy of the resulting certification listing can be seen under the certification listing article.
Picture 1
Construction of a test sample, consisting of a mock-up concrete floor frame, complete with penetrants. The concrete frame measures approximately 5’ x 9’ x 4― (ca. 1.5m x 2.3m x 10 cm). It has a large hole in the centre with many mechanical and electrical services traversing. The penetrants extend 1’ (30 cm) into the furnace and 3’ (91 cm) on the unexposed side. A firestop mortar is being applied here. Notice the
intumescent wrap strip surrounding the fibreglass pipe insulation. When the fire starts, this embedded intumescent will swell to take up the place of the melting insulation. The test was conducted in accordance with the Canadian firestop test method ULC[1] S-115 in Scarborough, Ontario.
Picture 2
The completed test sample is being lifted by crane to the test furnace for the fire resistance test. By
contrast, European furnaces can typically allow up to a 1m penetrant depth to reach into the furnaces. North American panel furnaces are not deep enough to accommodate this more realistic exposure.
Picture 3
After the completed test sample has been seated on a ceramic fibre gasket on the top of the furnace, gas is let in through perforated pipes at the bottom of the furnace. The ULC technician is now igniting the gas on each pipe to start the test. Thermocouples are located inside the furnace to make sure the fire resistance test is run in accordance with the prescribed time/temperature curve. Further thermocouples are located on the firestop, 1‖ or 25mm away from each penetrant and on each penetrant, 1‖ or 25mm up from the surface of the firestop. The length of time the test is run and/or however long it takes for fire to penetrate the firestop determines the F-Rating. The length of time required for a penetrant and/or the sample on average to exceed an average heat rise above ambient at the start of the test to exceed 140°C or 180°C at any single location – this determines the duration for the FT Rating (Fire and Temperature). If the hose-stream test is passed afterwards, the rating can then be expressed as an FTH Rating (Fire, Temperature and Hose-stream). The lowest of the three determines the overall rating, though it is possible to have a wide variety of T results, which can vary depending upn how well each such penetrant conducts heat.
Picture 4
At the conclusion of the fire resistance test, the test sample is lifted off the furnace and readied for a hose-stream test, which is NOT intended to simulate the effects of firefighting. Instead, it is to add a measure of reality of possible impacts, thermal shock and generally the brutal environment of a real fire, which is hard to simulate in pristine laboratory conditions. See this. With combustible penetrants like cables or
combustible firestops like silicone foam, it is not entirely unlikely even after two hours of fire to see residual flaming on the exposed side. For an example, see this picture. This was proven during a highly publicised fire test at ULC that encased the silicone foam with noncombustible sheathing in an attempt to justify in-situ installations in US and Canadian nuclear reactor facilities, as per submissions provided to Select Committee on Ontario Hydro Nuclear Affairs by Pickering, Ontario Regional Councillor Maurice Brenner
Picture 5
The duration and pressure of the hose-stream test are a direct function of the length of the test and the size of the test sample. The most typical test pressure is 30PSI, though 45PSI may also be used for fire tests of 4 hours duration or longer.
Picture 6
The test can be considered passed if no fire, water and no excessive heat traversed the sample or
penetrants. All results are tabulated and form part of the rating designations, which can be quite complex in the case of busy firestop tests such as this. For instance, an uninsulated copper pipe may have only a 5 minute T Rating, whereas that same pipe insulated with 2‖ or 50mm of rockwool may achieve a 2 hour T-Rating. Product certification listings resulting from such successful testing can be used to obtain the approval and acceptance of installed configurations on the part of the Authority Having Jurisdiction on construction sites. Listings are considered public knowledge, whereas the test report itself would be a proprietary item.
] Picture 7
Observations from both sides of the test assembly continue on the next day, once the sample has cooled down sufficiently. It is also customary to destroy the test sample, for two reasons: to learn from the effects of the test on the inside of the sample Research and development, as well as for a test laboratory which would issue a certification listing on the basis of the test to ensure that the listing reflects accurately what was installed inside the test assembly, in case and changes occurred that were not previously documented.
Firestop
Firestop after fire exposure during fire test in Tulsa, Oklahoma. This was an R & D test leading to a
fire-resistance rating of three hours.
A firestop is a passive fire protection system of various components used to seal openings and joints in fire-resistance rated wall and/or floor assemblies, based on fire testing and certification listings.
Unprotected openings in fire separations void the fire-resistance ratings of the fire separations that contain them, allowing spread of fire past the limits of the fire safety plan of the entire building. Firestops are designed to restore the fire-resistance ratings of rated wall and/or floor assemblies by impeding the spread of fire through the opening by filling the openings with fire resistant materials.