FIRE-RESISTANCE DESIGN

Fire-resistance Ratings, BXUVC


This category covers fire-resistance ratings assigned to the assemblies of construction materials as illustrated in the individual certifications, which have been established on the basis of the performance of test samples representative of the design of such assemblies when subjected to a fire-endurance test conducted in accordance with the specified standard for the following categories:

1. General Building Construction and Materials. The specimens are tested in accordance with the CAN/ULC-S101, "Standard Methods of Fire Endurance Tests of Building Construction and Materials," and are subjected to a fire exposure defined by the temperature-versus-time relationship depicted by the curve in Figure 1, "Time-Temperature Curve for Controlling Furnace Operation During Fire-Resistance Classification Tests - Standard Exposures."

Figure 1
Time-Temperature Curve for Controlling Furnace Operation
During Fire-resistance Classification Tests - Standard Exposures

2. Structural Steel Members used in the petrochemical industry or similar environment where a rapid rise in fire temperature is anticipated. The specimens are tested in accordance with ANSI/UL 1709, "Rapid Rise Fire Test of Protection Materials for Structural Steel," and are subjected to a fire exposure defined by the temperature-versus-time relationship depicted by the curve in Figure 2, "Time-Temperature Curve for Controlling Furnace Operation During Fire-Resistance Classification Tests - Rapid-Rise Fire Exposures." Design numbers established as a result of such tests are identified by the notation "Rapid-Rise Fire Test" on the design illustration.

Figure 2
Time-Temperature Curve for Controlling Furnace Operation
During Fire-resistance Classification Tests - Rapid-rise Fire Exposures

Essentially, the illustrated designs reflect the precise dimensions and condition of the sample assembly subjected to the fire-endurance test. Within practical limits, and with the exception of the items covered by the sections offering guidance in the variations which may be permitted in actual building construction in order that the anticipated performance of the assembly will not be impaired, a construction must duplicate the illustrated design and the details included in the associated text in order to achieve the indicated fire-resistance rating.

Authorities Having Jurisdiction should be consulted before installation.

Numbered items refer to the descriptive text below each drawing. Individual components of a proprietary nature or over which it is necessary to exercise control at the manufacturing location are certified under the Label Service or other Follow-Up Program of Underwriters Laboratories of Canada. Such items are identified in the text by a black dot thus •. Under these Services, periodic examinations and tests are conducted on samples selected at random from current production and stock. Each certified product bears the label or other identification of Underwriters Laboratories of Canada from which it may be determined that a product is suitable for use as a component in a particular design(s). Components intended for use with these assemblies are covered under Thermal Barrier Components (XCLZC).

It should be noted that the fire-resistance ratings assigned to these designs apply to assemblies in their entirety. Individual components are not assigned a fire-resistance rating but rather are designated for use in a design(s) in order that the assigned fire-resistance rating of the complete assembly may be achieved. Unless otherwise specified in the individual design or certification, attachments to structural steel have not been investigated.

All ratings assigned to floor and ceiling assembly designs, roof and ceiling assembly designs, wall and partition designs and column designs, are based on the assumption that the stability of any structural member supporting these designs is not impaired by the effects of fire on these supports.

Unless specifically described in the individual designs, penetrations through all or a portion of the assembly for piping, electrical access, air distribution, etc., can significantly affect the rating.

As supplementary information, in addition to the requirements of CAN/ULC-S101, a finish rating is established for assemblies containing combustible supports. The finish rating is the time at which the wood stud or joist reaches an average temperature rise of 139°C or an individual temperature rise of 181°C as measured on the plane of the wood nearest the fire.

Illustrated designs are identified by a design number with a letter prefix. The prefix letter designates a type of construction and the first number which follows designates the particular method of protection illustrated by the design with the final two numbers identifying a particular design.

The prefix letters representing the various groups of constructions are:

Prefix Letters Type of Construction
A, B or C Floor & Ceiling Designs - Concrete and Cellular Steel Deck
D, E or F Floor & Ceiling Designs - Concrete and Steel Floor Units
G, H or I Floor & Ceiling Designs - Concrete and Steel Joists
J or K Floor & Ceiling Designs - Concrete
L or M Floor & Ceiling Designs - Wood Joist
N or O Beam Designs for Floor & Ceiling Assemblies
P, Q or R Roof & Ceiling Designs
S or T Beam Designs for Roof & Ceiling Assemblies
U, V or W Wall & Partition Designs
X, Y or Z Column Designs

The type of protection employed is allocated to one of three main groups depending upon whether it is employed in the form of a shielding membrane, or directly applied, or the assembly, or components of the assembly are left unprotected. These groups are further subdivided, where appropriate, as follows:

NUMBERING SYSTEM FOR FIRE-RATED ASSEMBLIES

TYPES OF PROTECTION
Membrane Protection Direct-Applied Protection Unprotected
Types of
Construction

000-099

100-199

200-299

300-399

400-499

500-599

600-699

700-799

800-899

900-999
Floors & Ceilings:
A, B or C
Concrete and
Cellular Steel
Deck
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
D, E or F
Concrete
and
Steel
Floor
Units
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
G, H or I
Concrete
and
Steel
Joists
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
J or K
Concrete
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
L or M
Wood
Joist and Combustible Assemblies
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
Beams:
N or O
Floor & Ceiling
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
Roof & Ceiling:
P, Q or R
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
Beams:
S or T
Roof & Ceiling
Concealed Grid System (Spare) Exposed Grid System (Spare) Metal Lath Gypsum Board Miscellaneous Cementitious Sprayed Fibre Unprotected
Wall & Partition:
U, V or W
Building Partition Panel Units Insulating Concrete (Spare) Wood Stud, Gypsum Board, Lath and/or Plaster Metal Stud, Gypsum Board, Lath and/or Plaster Misc. Support, Gypsum Board, Lath and/or Plaster Metal Panels, Gypsum Board, Lath and/or Plaster Metal Panels or Supports Cementitious Metal Panels or Supports Sprayed Fibre Masonry
Columns:
X, Y or Z
Building Units Prefabricated Mineral and Fibre Board (Spare) Metal Lath and Plaster Gypsum Board Miscellaneous Cementitious Sprayed Fibre (Spare)

The numbers indicated as "Spare" in the above table are for future expansion and to accommodate new types of systems developed in the future.

RESTRICTED-LOAD USE CONDITIONS

When a test assembly complies with the acceptance criteria, a detailed description of the assembly, its performance in the fire test and other pertinent details, such as specifications of materials, certifications coverage and alternate assembly details, are included in a report for the test sponsor. Sponsors may provide copies of the complete test report upon request. The report also contains a summary of important features of the rated assembly.

A complete description of each rated fire-resistive assembly can be found in the ULC Fire Resistance Directory.

CAN/ULC-S101 requires loads applied to test samples be calculated using the limit states design method specified in the "National Building Code of Canada" (NBCC). CAN/ULC-S101 also requires fire-resistive assemblies with ratings obtained from samples tested with applied loads less than the maximum calculated value be identified. Load restriction due to the sponsor of the test electing to test the assembly under load less than specified by the limit states design methods are identified as "Load Restricted." Assemblies investigated with loading computed in accordance with working stress design methods are identified as "Load Restricted - Assembly evaluated in accordance with Working Stress methods, for use under Limit States Design methods refer to information under BXUVC."

The percent load reductions for typical assemblies in Table 1 are based upon loading calculated in accordance with the working stress design method as compared to loading calculated in accordance with the limit states design method. The calculations were performed for assemblies representing spans and member sizes of typical fire-test assemblies. The loads were calculated assuming a span of 4 m for floors and roofs and 3 m for walls.

The NBCC requires that buildings and their structural components be designed to have sufficient strength and stability so that the factored resistance (ϕR) is greater than or equal to the effects of factored loads. The value for ϕ and R are specified in the applicable limit state design methods, for concrete, masonry, steel and timber.

Some fire-resistive designs are specified with a Load Restricted Factor. When using fire-resistive designs with a Load Restricted Factor, the factored resistance (ϕR) of the structural members or components should be reduced by multiplying the factored resistance (ϕR) by the Load Restricted Factor specified in the individual ULC fire-resistance designs.

The Load Restricted Factor should be applied to the factored resistance (ϕR) of all structural members or components, including but not limited to, factored moment resistance (Mr), factored shear resistance (Vr), factored tensile resistance (Tr), and factored compressive resistance (Cr).

Table 1


Type of Assembly
Percent Load Reduction
(LSD-WSD) / LSD

Load Restricted Factor
W200x42 noncomposite steel beam 12% 0.88
W200x42 composite steel beam 29% 0.71
Floor / Roof supported by open web steel joists 4% 0.96
Floor supported by cold formed steel channels 4% 0.96
Floor supported by 38 by 235 mm wood joists 35% 0.65
Wall supported by 38 by 89 mm wood studs 18% 0.82
Steel columns 0% None

The ratings for steel columns do not have a "Load Restricted Factor" as these ratings are based on temperature limitations. No loading is applied to steel columns during the fire test.

The engineer of record should be consulted whenever fire-resistive assemblies with "Load Restricted Factors" are selected. The indicated load reductions are based upon Factored Load effects that are governed by the reduced Factored Resistance of the structural elements. The selection of structural elements is, at times, based upon service limits, such as deflection and vibration. These factors and others, such as the change in material strength properties as a function of temperature, should be considered when selecting fire-resistive assemblies with Load Restricted ratings.

The Load Restricted Factors in Table 1 are intended to be used as a guide and are applicable to the specific structural members specified in Table 1.

FLOOR AND ROOF AND CEILING CONSTRUCTIONS
AND BEAM PROTECTION

Unless otherwise stated in the individual designs, the load capacity of wide-flange-shaped steel beams assumes that the beams are manufactured from steel with yield strength of 250 MPa.

The time ratings assigned to each illustrated design are given in terms of a restrained or an unrestrained condition, or both. A restrained condition in a fire test is considered to be one in which the expansion at the supports of a load-carrying element resulting from the effects of the fire is resisted by forces external to the element. An unrestrained condition is one in which the load-carrying element is free to expand and rotate at its supports.

Restrained ratings are intended for application to assemblies and structural members considered suitable for use in building construction where the structural members are designed with continuity, or where the construction is otherwise expected to be restrained against thermal expansion under fire conditions. An unrestrained rating is applied to assemblies and structural members considered suitable for use in building construction where the structural members are simply supported and unrestrained against thermal expansion.

Restrained assembly ratings, unrestrained assembly ratings, and unrestrained beam ratings have been assigned to each assembly where appropriate.

The unrestrained beam rating associated with a particular design is applicable to beams protected in the manner described by the design when used with a floor or roof construction having a comparable or greater capacity of heat dissipation than the floor or roof with which it was tested.

Unless specifically described in the designs, openings penetrating the floor, roof or ceiling for piping, electrical access or air distribution can adversely affect the indicated rating.

WALLS AND PARTITIONS

The wall and partition designs illustrated are identified by a design number and an hourly rating.

In accordance with CAN/ULC-S101, the minimum size of wall fire tested is 9.3 m2 and the height of the wall is 3050 mm. In the field when walls greater than 3050 mm in height are constructed, the slenderness of the wall constructed in the field should not be less than the slenderness of the 3050 mm high wall specified in the ULC Design. For calculation of slenderness, reference should be made to the material specific structural design standard.

With the exception of support (e.g., studs) and fastener (e.g., nails, screws) spacings, the dimensions indicated in the following designs are intended to be construed as the minimum allowable for each rated assembly. Support and fastener spacings stated are the maximum allowable.

Additional layers of gypsum board are permitted to be added to any design.

As stated in CAN/ULC-S101, the test specimen is to be representative of the construction for which classification is desired as to materials, workmanship, and details such as dimensions of parts, and is to be built under conditions representative of those practically applied in building construction and operation. Accordingly, wall and partition hourly ratings are applicable when walls are constructed in a true vertical position. Unless otherwise noted in an individual design, the performance of angled walls or walls constructed in the horizontal position has not been investigated.

Certified and labelled mineral fibre thermal building insulation processed from rock, slag and glass only may be used in ULC nonload-bearing wall assembly designs consisting of wallboard and steel or wood studs with a fire-resistance rating not exceeding two hours when illustrated without insulation, without detracting from the rating assigned to the assembly.


Note:

This applies to ULC nonload-bearing wall assemblies that utilize proprietary (certified) gypsum wallboards as specified in the individual designs.

Where reference is made to a specific type of screw for attaching gypsum wallboard, the following specifications apply:


Head
Dia., mm

Screw Type

Length
Shaft
Dia., mm
Min Max
Type S Nominal length shall
be min length
3.6 - 3.9 8.0 9.3
Type G Nominal length shall
be min length
5.3 - 5.5 7.6 9.3
Type W Nominal length shall
be min length
3.6 - 3.9 8.0 9.3

These screws are self-drilling, self-tapping steel screws with a case-hardened surface, corrosion-resistant treated, flat-top head and No. 2 Phillips design driving recess, 2.6 mm minimum depth.

Wood Studs — The size of studs are minimum unless otherwise stated in a design. The spacing of studs is a maximum unless otherwise stated in a design. Spacing between parallel rows of studs are minimums unless otherwise stated in a design.

Steel Studs — The dimensions and gauge of steel studs are minimums. The hourly ratings apply when the steel studs are of a heavier gauge and/or larger dimensions than specified in a design. Spacing between parallel rows of studs are minimums unless otherwise stated in a design.

The superimposed load of bearing walls utilizing steel studs should be based on the capacity of the studs as determined by CSA-S136 (2007), "North American Specification for the Design of Cold-Formed Steel Structural Members."

Where lateral support of studs (by means of straps, channels or similar steel members) is required in the design, the loads applied to steel studs should be based on the steel-braced design. The loads based on sheathing bracing should not be assumed, unless otherwise stated in the design.

The loads applied to steel studs having a yield stress higher than the stated minimum should be based upon the specified minimum yield stress stated in the design.

Non-load-bearing steel studs are produced in accordance with ANSI/AISI S201 (2007), "North American Standard for Cold-Formed Steel Framing - Product Data." In accordance with ANSI/AISI S201, the minimum flange width should be 31.8 mm and the minimum return lip should be 4.8 mm.

EQUIVALENT OPENING FACTOR (FEO)

Fire-resistance ratings of wall assemblies can be assigned on the basis of the performance of the assembly when tested and investigated in accordance with CAN/ULC-S101. However, the NBCC allows for an exception from the unexposed surface temperature rise requirements for exterior wall assemblies having a limiting distance of 1.2 m or more, provided correction is made for radiation from the unexposed surface at the desired duration of exposure.

Where the surface temperature on the unexposed surface of an exterior wall assembly exceeds the limitations of the CAN/ULC-S101 test, an allowance can be made for radiation from the hot unexposed wall surface by adding an equivalent area of unprotected opening to the area of actual openings. In order to calculate this equivalent area, an equivalent opening factor (FEO) must be calculated as shown below:

(Tu + 273)4
FEO
(Te + 273)4

Where:

Tu = Average temperature in degrees Celsius of the unexposed wall surface at the time the required fire-resistance rating is reached under test conditions, and

Te = 892°C for a fire-resistance rating of not less than 45 minutes; 927°C for a fire-resistance rating of not less than 1 h, and 1010°C for a fire-resistance rating of not less than 2 h.

FEO = An equivalent opening factor derived from test data.

Where this information is available, it has been provided in the individual designs.

COLUMN PROTECTION

The column designs illustrated are identified by a design number and an hourly rating. The dimensions given in the following designs are intended to be constructed as the minimum allowable for each rated assembly. Where the material applied to the column is likely to be damaged by moving vehicles, handling of merchandise and other sources, the applied material is intended to be protected against such possible damage.

METRIC CONVERSION

This metric edition has been "hard" converted where possible. However, many dimensions were "soft" converted as metric equivalents do not exist.

In floor/ceiling and roof/ceiling designs, the spacings of the structural members have been soft converted (e.g., 48 in. becomes 1220 mm). For walls and partitions, the stud spacings which were most often specified as 16 or 24 in. have been converted to 400 and 600 mm, respectively.

Manufacturers of some certified products, such as gypsum wallboard, acoustical material and steel framing members, are able to provide both metric and yard/pound sizes or modules of the products that are referenced in the illustrated designs. Care should be taken to employ compatible modules, such as in the case of lay-in panels and associated steel framing members. Also, in the case of designs employing gypsum wallboard, particular attention should be given to the location and staggering of joints, as specified in the particular design. Nominal fastener spacings should not be exceeded.

AIR-HANDLING SYSTEMS

The fire tests are conducted without air movement and, therefore, fire-resistance ratings that have been assigned to floor or roof and ceiling assemblies incorporating provision for such air movement are contingent upon the inclusion of means of effectively stopping the air flow in the event of fire.

Where firestop flaps are specified, it is necessary that they be equipped with spring catches and corrosion-resistant hinges and that flaps designed to close by gravity be installed so as to close in the direction of the airflow. Air duct throat diameters are considered to be the maximum individual diameters appropriate for the design and its assigned fire-resistance ratings and the maximum area of duct given in the designs refers to the aggregate area of supply and return duct openings for each 10 m2 of ceiling area. Alternative duct outlet protection may be provided by the following illustrated systems when specified in the individual designs. These systems have only been investigated for their comparable effectiveness in retarding the transfer of heat into the plenum area.

Except where noted, the air diffusers used in the test assemblies were of the surface-mounted type, which also support the surrounding acoustical material by a flange at least 25 mm wide. The use of a lay-in-type air diffuser or return-air grille as an alternative to the surface-mounted type is permitted, provided that, when larger than its associated duct drop, the diffuser or grille pan is of welded or bolted steel construction and is supported on all four sides by steel framing members. The members are supported at their intersection points by hanger wires and the exposed back of the lay-in diffuser or grille pan is protected by labelled batts and blankets specifically certified for that purpose. See Batts and Blankets (BZJZC).

In lieu of ceiling firestop flaps, air-terminal units may be used for the protection of duct outlets in the fire-rated floor and roof and ceiling assemblies. These air-terminal units include the linear slot type, ceiling air diffuser types using flexible Class 1 air duct materials or connectors, and ductless return air grille types. See Air Terminal Units (BZGUC).

Duct Outlet Protection System A

Note: All dimensions are in millimetres.

1. Steel Air Duct — Construction and support provisions are specified by the individual fire-resistance designs. Duct outlet intended to be provided with a louvered steel air diffuser, secured with steel fasteners.
2. Glass-Fibre Duct Lining — Minimum 25 mm thick, 48 to 80 kg/m3 density, unfaced or faced with paper, foil, plastic film or asphalt emulsion. Affixed to inside or outside of duct with adhesive or steel fasteners or both. Lining is intended to cover the full perimeter of the duct, extending at least 300 mm beyond the edges of the duct outlet. Lining in bottom of duct is intended to be cut flush with the edges of the duct outlet. The lining is intended to comply with the NBCC for interior linings. Materials that accommodate these requirements are covered under Air Duct Materials (BQXRC).
3. Acoustical Material — Nominal 16 mm acoustical lay-in panel certified by ULC for use in fire-resistance designs and which has been assigned an appropriate surface burning characteristic. Laid on top of duct, extending at least 75 mm beyond the sides of the duct and 150 mm beyond sides of duct outlet along the width of duct, and extending at least 450 mm beyond sides of duct outlet along length of duct. More than one panel may be butted together to form a panel of the required dimensions. The acoustical material is intended to comply with the requirements of the NBCC for duct outlet coverings. Materials that accommodate these requirements are covered under Acoustical Materials (BYITC).

Duct Outlet Protection System B

Floor and Ceiling and Beam Assemblies

Note: All dimensions are in millimetres.

1. Steel Air Duct — Construction and support provisions as specified in the individual designs. Outlet intended to be provided with a louvered steel diffuser, fastened securely with steel fasteners.
2. Mineral Wool Batts — 32 mm thick mineral wool batts, 56 to 88 kg/m3 density. Top piece extends at least 75 mm beyond the sides of the duct and 150 mm beyond the edges of the duct outlet. Side pieces extend from the lower face of the top piece to the upper face of the ceiling membrane along the entire length of the top piece. Side pieces tied to top piece with 1.2 mm galvanized steel wire, 450 mm OC. The mineral wool batts are intended to comply with the NBCC for duct outer coverings. Materials that accommodate these requirements are covered under Batts and Blankets (BKNVC) and Batts and Blankets (BZJZC).

Light Fixtures

Light-fixture bodies and associated hardware are required to be of steel in order that the assigned fire-resistance rating may not be impaired. It is also necessary that the installed fixtures be without openings into the plenum. Unless otherwise stated in the individual designs, recessed light fixtures are not intended to serve as an outlet and/or inlet for heated ventilating and/or cooled air to a duct, air passage or plenum.

Unless otherwise stated in the section which discusses permissible variations from tested designs and the text related to a particular design, the opening indicated in the individual designs refers to the maximum area of the light fixture for use in each 10 m2 of ceiling area.

Protection — It is necessary that light fixtures be protected in the precise manner indicated in the illustrated designs with respect to material and form in order that the performance associated with the fire-resistance rating assigned to a design may not be impaired.

Fixtures which do not permit the specified systems of protection and associated suspension details may also impair the fire-resistance rating implied by the design.

Floor and roof and ceiling constructions are tested with a recessed light fixture with sloping sides, 0.68 mm thick painted steel housing, and 0.55 mm thick painted steel ballast cover unless specified otherwise. However, the fire-resistance rating assigned to the assembly is applicable when light fixtures and their corresponding protection systems as specified under Recessed Light Fixtures (CDGAC.

Fasteners

In those assemblies employing gypsum wallboard membranes, where reference is made to a specific type of screw for attaching the gypsum wallboard, the following specifications apply:


Head
Dia., mm

Screw Type

Length
Shaft
Dia., mm
Min Max
Type S Nominal length shall
be min length
3.6 - 3.9 8.0 9.3
Type G Nominal length shall
be min length
5.3 - 5.5 7.6 9.3
Type W Nominal length shall
be min length
3.6 - 3.9 8.0 9.3

These screws are self-drilling, self-tapping steel screws with a case-hardened surface, corrosion-resistant treated, flat-top head and No. 2 Phillips design driving recess, 2.6 mm minimum depth.

Steel Floor Units

A small number of designs have two assigned ratings for the unrestrained assembly. This is in consideration of the requirements of CAN/ULC-S101 which, when considering the unrestrained assembly condition, imposes a temperature limit on spans other than those employed in the test assembly. Therefore, there is one unrestrained assembly rating for the tested (or shorter) span, and a lower unrestrained assembly rating for longer spans.

Steel Framing Member Systems

In those assemblies employing steel framing member systems suspended below the structural members, provision for the expansion of the systems under fire conditions is necessary. Such provision may take the form of an expansion joint in each length of main tee, by providing clearance at the ends of each main tee or may be built into the joint design of modular system. When such a condition existed in a fire test, it is indicated in the text of each certified design. In actual building construction the provisions for expansion must be included, even though the length of the main tees may be shorter or longer than that specified by the design.

Roof and Ceiling Constructions

Roof and ceiling constructions are tested with Class C, 3-ply saturated Type 15 felt roof covering applied with hot-mopping asphalt, unless specified otherwise. However, the fire-resistance rating assigned the assembly is applicable when Class A or B built-up roof coverings consisting of alternative layers of felt and asphalt are substituted. See Built-Up Roof Covering Materials (TGFUC) for further information on the requirements for built-up roof coverings.

CONSIDERATION OF VARIATIONS FROM TESTED DESIGNS

This section provides supplementary information that may assist users in relating forms of building construction that are intended to follow the specifications associated with a certified design, but which may, for various reasons, deviate from those specifications.

Size of Assembly and Assembly Components

The fire-resistance ratings established as a result of the application of the test method on structural components protected with materials other than thin-film intumescent and mastic coatings or intumescent fire-resistive materials are appropriate for use in building constructions employing structural components having greater size (mass per metre, cross-sectional area or section modulus for lumber or concrete elements) or greater M/D ratios for steel elements; where M is the mass in kilograms per metre and D is the heated perimeter of the steel structural component in metres, than those illustrated in the established designs, thus permitting the extension of test data to structures incorporating spans in excess of those tested. Where an equation is shown, other limitations specific to the individual design are also applicable.

For structural steel elements protected by a thin-film intumescent and mastic coating or intumescent fire-resistive materials, the fire-resistance ratings are applicable to structural steel components of the same shape having greater M/D ratios; where M is the mass in kilograms per metre and D is the heated perimeter of the structural component in metres. Where an equation is shown, other limitations specific to the individual design are also applicable.

Where assemblies employ structural members located on more than 1220 mm centres, the data obtained from the fire test and the provisions of the test method accommodate unlimited spacing of the structural members, provided that structural requirements are met, except that, in the case of membrane-protected roof-ceiling assemblies incorporating conventionally designed bridging, the spacing of the structural members is not intended to exceed that employed in the test.

Spacing and Application of Structural Members

Beams (and joists) forming part of an assembly and which are located on more than 1220 mm centres while exposed to standard fire conditions within the limits prescribed by the test method are considered as structural members for the purpose of assigning fire-resistance ratings. Such fire-resistance ratings appear as unrestrained beam ratings in the designs. Where beam designs have been assigned fire-resistance ratings on the basis of their performance when tested together with a section of a representative floor or roof construction rather than as a part of a floor or roof assembly, similar considerations apply with regard to the applicability of the assigned ratings.

Where assemblies employ multiple joists, such that the joists are spaced less than 1220 mm on centres, the temperature and structural performance data obtained from the fire test and the provisions of the test method accommodate spacing of joists in actual building construction up to a maximum of 1220 mm, provided that the structural requirements arising from the increased floor span are met.

Coating Materials

Coating materials include products identified as: 1) Spray-applied Fire-resistive Materials and 2) Thin-film Intumescent and Mastic Coating.

Unless specifically detailed in a design or in the product certification information, the interaction of dissimilar fireproofing materials on the same structural element or at the intersection of structural members, and the adherence of one product to the other, has not been investigated under fire-test conditions.

Unless specifically detailed in a design or in the product certification information, the impact of galvanization applied to structural steel members has not been investigated under fire-test conditions. Galvanization may impact the adhesion of spray-applied fire-resistive materials or mastic and intumescent coatings.

Sprayed-Applied Fire-Resistive Materials

The type of material is specified in each design. Materials that have been investigated for exterior applications are so indicated in the individual designs.

The surfaces on to which the material is intended to be applied must be free of dirt, oil and scale. Mixing and spraying instructions are printed on each bag of material.

The densities shown in the illustrated designs are intended to be considered as the minimum average densities of the material that will provide the performance indicated by the design.

Dry-density measurements may be determined by removing sections of at least 150 x 150 mm randomly selected from the building, subjecting them to 50°C in an oven until constant mass is obtained, followed by accurate weighing, measuring and calculation of the density in kg/m3. Constant mass is usually obtained after 24 to 48 h exposure within a 50°C oven.

The sprayed-applied fire-resistive material thickness specification given in a design may be considered the minimum average thickness of the individual thickness readings measured in accordance with ANSI/ASTM E605, "Standard Test Methods for Thickness and Density of Sprayed Fire-Resistive Material (SFRM) Applied to Structural Members." Individual measured thickness, which exceeds the thickness specified in a design by 6 mm or more, is intended to be recorded as the thickness specified in the design plus 6 mm. No individual measured thickness should be more than 6 mm less, or more than 25% less, than the thickness specified in the design.

The thickness of the sprayed-applied fire-resistive material should be corrected by applying additional material at any location where: (1) the calculated average thickness of the material is less than that required by the design, or (2) an individual measured thickness reading is more than 6 mm less than the specified thickness required by the design.

Selected areas of the structural frame and/or floor area are intended to be chosen to obtain representative average thicknesses. Thickness readings on floor or wall areas are intended to be taken symmetrically over the selected area. The average of all measurements should be considered the average thickness of the area. Thickness measurements on beams and/or columns are intended to be made around the member at sections within 300 mm of each other. The average thickness should be considered the average of the readings taken at both sections.

New Requirements for the Use of Sprayed-Applied Fire-Resistive Materials on Primed Steel Surfaces

The surfaces on which the material is intended to be applied must be free of dirt, oil and loose scale. Surfaces may be primed with UL certified primers/paints covered under Primers for Structural Steel (CGJM).

The following method of determining the bond strength of the spray-applied materials only applies to primers or paints not covered under Primers for Structural Steel (CGJM). Unless specifically prohibited in a design, materials identified as Spray-applied Fire-resistive Materials (CHPXC) may be applied to primed or similarly painted wide-flange steel shapes and pipe and tube-shaped columns, provided: (A) the beam flange width does not exceed 305 mm; (B) the column flange width does not exceed 406 mm; (C) the beam or column web depth does not exceed 406 mm; (D) the pipe outer diameter or tube width does not exceed 305 mm; (E) bond tests conducted in accordance with ANSI/ASTM E736, "Standard Test Method for Cohesion/Adhesion of Sprayed Fire-Resistive Materials (SFRM) Applied to Structural Members," should indicate a minimum average bond strength of 80% and a minimum individual bond strength of 50% when compared to the bond strength of the fire-resistive coating as applied to clean uncoated 3.2 mm thick steel plate. The average and minimum bond strength values should be determined based upon a minimum of five bond tests conducted in accordance with ANSI/ASTM E736.

The bond tests need only be conducted when the fire-resistive coating is applied to a primed or similarly painted surface for which acceptable bond strength performance between the primer or other similar material and the fire-resistive coating has not been measured. A bonding agent may be applied to the primed or similarly painted surface to obtain the minimum required bond strength where the bond strengths are found to be below the minimum acceptable values.

As an alternative to the bond test conducted on control samples applied to an uncoated steel plate, the following method may be used for unknown coatings in existing structures. Sections of painted steel are to be coated with a bonding agent compatible with the sprayed material being used on the project. The treated and untreated substrates should be coated with material, cured and subjected to five bond tests each, in accordance with ANSI/ASTM E736. If the failure mode of the sections treated with the bonding agent is 100% cohesive in nature, it will be acceptable to use this bond test value as the control bond strength. The value obtained on the untreated painted section should be compared to the control value using the minimum 80% average, 50% individual bond strength acceptance criteria established in ANSI/ASTM E736.

If condition (E) is not met, a mechanical bond may be obtained by wrapping the structural member with expanded metal lath (minimum 0.927 kg/m2).

If any of the conditions specified in (A), (B), (C) or (D) are not met, a mechanical break should be provided. A mechanical break may be provided by mechanically fastening one or more minimum 0.927 Kg/m2 metal lath strips to the flange, web or tube and pipe surface either by weld, screw, or powder-actuated fasteners, on maximum 305 mm centers, on each longitudinal edge of the strip, so that the clear spans do not exceed the limits established in conditions (A), (B), (C) or (D) as appropriate. No less than 25% of the width of the oversize flange or web element should be covered by the metal lath. No strip of metal lath should be less than 90 mm wide.

As an alternative to metal lath, the mechanical break may be provided by the use of minimum 2.5 mm steel studs with minimum 0.36 mm galvanized steel disks if such a system is described in a specific design (usually bottomless trench in an electrified floor design) for the fire-resistive coating being applied. The studs should be welded to the oversize element in rows such that the maximum clear span conforms to conditions (A), (B), (C) or (D) as appropriate. The spacing of studs along each row should not exceed 610 mm and a minimum one stud per 0.165 m2 should be provided.

Where metal lath strips or steel studs and disks are used, acceptable bond strength as described in item (E) should also be provided. A bonding agent may be applied to the painted surface to obtain the required minimum bond strength where bond strengths to a painted surface are found to be below minimum acceptable values.

Cavities, if any, between the upper beam flanges and open web steel joist (OWSJ) flanges, and the steel floor or roof units are intended to be filled with the fire-resistive coating material applied to the beam and OWSJ flanges, unless specified otherwise in the individual designs.

Adjustment of Thickness of Sprayed-Applied Fire-Resistive Material
for Beams of Alternate Size

Alternate-size, W-shape steel beams may be substituted in designs that have been assigned beam ratings and employ sprayed-applied fire-resistive material (700-799, 800-899 and 900-999 designs), provided the thickness of sprayed protection is adjusted accordingly by the following equation:

Where:

T = Thickness (mm) of spray-applied material

M = Mass of steel beam (kg/m)

D = Heated perimeter of steel section in metres (m), equal to 2d + 3b where d = depth of section and b = flange width

Subscript 1 refers to given beam size and protection thickness specified in the individual designs.

Subscript 2 refers to desired beam size and required protection thickness.

and:

M/D values are not less than 23

T2 values are not less than 10 mm

Thickness for Thin-Film Intumescent and Mastic Coating

The dry-film thickness of thin-film intumescents and mastic coatings noted in the individual designs should be considered the minimum average thickness of the individual thickness readings measured in accordance with AWCI Technical Manual 12-B, "Standard Practice for the Testing and Inspection of Field Applied Thin Film Intumescent Fire-Resistive Materials; an Annotated Guide." The maximum average dry-film thickness of thin-film intumescents and mastic coatings should not exceed by more than 10% the thickness stated in the established design.

In individual designs consisting of steel columns protected with thin-film intumescent and mastic coatings where such designs include equations for the computation of the fire-resistance ratings or the required dry-film thicknesses of the coatings, the equations are only valid within the limitations specified in the designs. Extrapolation of data outside the specified limitations will invalidate the fire-resistance ratings associated with the designs.

Suspended Membrane Protection

In those assemblies employing membrane protection suspended below the structural members, the depth of the plenum space between the underside of the floor and the top of the ceiling protection may be increased to accommodate deeper structural members without detracting from the indicated performance of the design. However, the minimum dimension between the bottom flange (chord) of the structural member and the protective membrane should be maintained.

Where the spacing of the joists has been increased in a field application beyond that indicated in the illustrated design, and within the 1220 mm limitation referred to above, it may be necessary to provide intermediate suspension points. Such intermediate suspension points are provided by 1.6 mm cold-formed steel channels 51 mm deep with 13 mm flanges, or two 1.2 mm cold-formed steel channels 38 mm deep with 13 mm flanges nested and placed perpendicular to and on top of the lower chords of the joists, and secured to each joist with three loops of 1.2 mm galvanized soft-steel wire. Hanger wire at the intermediate suspension points should be selected on the basis of the requirements in the text of the particular design under consideration.

It should be noted that a ceiling board size or range of sizes is indicated in each design employing suspended membrane protection. The use of ceiling board sizes and suspension system module sizes not covered by the design may impair the performance suggested by the fire-resistance rating assigned to the design.

Steel Floor or Roof Units

In assemblies employing steel floor or roof units in fluted, cellular or blended systems, the variations accommodated by the design have been established on the basis of performance during the fire test. The considerations include structural performance, retention of applied protection or shielding membrane protection and temperature transmission through the units to the unexposed surface of the test assembly. The individual designs provide for a specific type or combination of types of floor or roof units, as well as specifying the minimum depth of section appropriate to the particular design; see the individual certifications under Steel Floor Units (CHWXC) for a detailed breakdown.

The thickness of material specified in the individual designs reflects the actual thickness used in the fire test. Variations other than those provided for in the individual designs or certifications may detract from the indicated fire-resistance rating. Deeper sections consistent with structural requirements may be used as indicated in the individual certifications of floor units.

For constructions that have been subjected to a fire test with steel floor units designed for composite action and loaded so as to develop the theoretical stress contemplated by the design, the list of components associated with the design provides for the use of composite or noncomposite floor units. Conversely, the fire-resistance rating associated with a design may not be maintained if composite units are employed in building construction intended to duplicate the details of an assembly which has been assigned a fire-resistance rating on the basis of its performance when tested with noncomposite floor units.

The connection of the steel floor or roof units to the supporting steel structure is specified in the individual design. For steel floor and roof units when puddle welded connections to the supporting steel beam is specified in the individual design, the puddle welds may be substituted with Power Driven Fasteners that provide equivalent strength capacity.

Roof Insulation

The performance of roof and ceiling assemblies can be significantly affected by the type and thickness of roof insulation employed in the test assembly; a reduction in thickness could lead to prematurely reaching higher temperatures on the unexposed surface, whereas an increase in the thickness could cause early structural failure.

Accordingly, variations from the types and thicknesses of roof insulations provided for in the designs may be expected to detract from the indicated fire-resistance ratings.

Where floor and ceiling assemblies incorporating a concrete topping of 50 mm or more are used as roof constructions, the use of any certified rigid roof insulation and Class A, B or C built-up roof covering on top of the concrete slab would not detract from the assigned fire-resistance ratings.

Transfer of Components from One Design to Another

Structural Members — The standard test method provides for the transfer of structural members from one assembly to another (when selecting a design intended to accommodate the requirements of a particular form of building construction), where:

A. The unrestrained rating of the structural member being transferred is equal to or greater than that of the structural member being replaced.
B. The restrained rating of the structural member being transferred or of the assembly in which that member was tested is equal to or greater than that of the assembly into which the member is being transferred.
C. The capacity for heat dissipation from the structural member in the assembly to which it is being transferred is equal to or greater than that of the assembly in which it was tested.
D. The capacity for heat transfer to the structural member in the assembly to which it is being transferred is equal to or less than that in the assembly in which it was tested.
E. The load deflection characteristics of the assembly to which the structural member is being transferred is equal to or lower than that of the assembly in which it was tested.

In order to transfer structural members, all of the above conditions must be met.

Examples of the specific conditions:

A. Unrestrained Beam and Restrained Assembly Rating Conditions —

Given an assembly having a 3 h restrained assembly rating and a 2 h unrestrained beam rating, in order to transfer a beam tested as a loaded restrained beam (N and O Series designs), it is necessary to apply the thickness of fire-resistive material sufficient for a 2 h unrestrained beam rating or a 3 h restrained beam rating, whichever is greater. A beam from a "beam only" design which does not have a restrained beam rating may only be transferred into assemblies having Restrained Assembly ratings equal to or less than the assembly rating for which that beam is qualified.

In order to transfer a beam tested in another assembly, it is necessary to select an assembly having a 3 h restrained rating and including a 2 h unrestrained beam.

B. Heat Dissipation Condition —

Structural members may be transferred into assemblies having an equivalent or greater volume of concrete per unit of floor area.

Structural members may be transferred from an assembly incorporating structural low-density concrete into an assembly incorporating normal-density concrete.

Structural members may be transferred from a roof assembly comprising a metal deck, insulation, and built-up roofing into a protected or unprotected floor assembly utilizing concrete topping.

C. Heat Transfer Condition —

Structural members may be transferred from assemblies tested with all cellular or blends of cellular and fluted units into assemblies with all fluted or an equal or lower ratio of cellular to fluted floor units.

Structural members may be transferred from unprotected deck assemblies into protected deck assemblies.

Structural members may be transferred from protected deck assemblies into unprotected deck assemblies, provided that the fire-resistive material is not a thin-film intumescent coating or mastic coating, and the fire-resistive material of the same thickness as is used on the protected deck is applied to the floor construction for a width of 300 mm either side of the top flange.

Structural members may be transferred from protected or unprotected steel deck assemblies into assemblies incorporating soffits of exposed concrete, provided that the fire-resistive material is not a thin-film intumescent coating or mastic coating, and the fire-resistive material is applied to the floor construction to a minimum thickness of 10 mm and for a width of 300 mm either side of the top flange. This requirement is intended to minimize the risk of disruption of the protection to the structural member as a result of spallation of the concrete.

Structural members are not intended to be transferred from protected or unprotected steel deck assemblies into assemblies incorporating soffits of exposed concrete where the fire-resistive material is thin-film intumescent coating or mastic coating.

D. Load Deflection Condition —

Noncomposite or composite structural members may be transferred into designs rated with composite structural members.

Only noncomposite structural members may be transferred into designs rated with noncomposite structural members.

It should be noted that these provisions exclude the transfer of structural members tested with floor assemblies to a building construction in the form of a roof construction. The performance of structural members, protected in the same manner, when tested under a floor assembly, is significantly different when tested under an insulated roof assembly, the roof deck assembly representing the more severe test condition upon the structural member.

The foregoing provisions are essentially intended for application to structural members employing directly-applied protection. In floor or roof and ceiling assemblies which incorporate structural members protected with a suspended-ceiling membrane, it is not appropriate to transfer the members to other designs, and a separate fire-resistance rating for the beam is given for information purposes only.

Membrane Protection — The performance and compatibility of certain combinations of components employed in suspended-membrane protection systems have been investigated in connection with the establishment of the designs. Unless specifically indicated in the list of components associated with a design, interchange of components, such as acoustical material employed in the form of ceiling board or tiles and steel framing member suspension systems with those components associated with other certified designs can detract from the indicated fire endurance of the assembly.

The established ratings are not intended to accommodate variations in the design, such as a change of opening sizes per unit area in the ceiling associated with the installation of air ducts, lighting fixtures, etc., on the basis of the apparent performance of these components in assemblies other than the assembly with which they were tested.

Applied Protection — Interchange of forms of applied protection with regard to type, thickness or condition, from one certified assembly to another, may impair the fire-resistance rating implied by the design.

Concrete

Strength — The nominal compressive strength specified in the individual designs may be reduced by 3.5 MPa as a minimum. The maximum compressive strength is not limited. Variations in the strength of the concrete employed in actual building construction will alter the fire endurance of an assembly. The extent of this effect depends on the type of construction and the strength of the concrete.

Thickness — An increase in the thickness of concrete topping will add to the fire endurance of an assembly. Variations in the type of aggregate employed will affect the insulating characteristics of the concrete topping. Where specific data is available concerning such variations, it is usually possible that changes in the fire-resistance rating assigned to a design may be accommodated following engineering studies conducted by ULC during which all factors pertaining to the effect of such changes on the anticipated performance of an assembly can be taken into consideration.

Structural Low-density Versus Normal-density Concrete — Unless specifically noted in a design, the interchange of structural low-density and normal-density concrete is not provided for in certified assemblies. In those cases where provision is made for use of structural low-density and normal-density concrete, such designs have been established on the basis of data obtained from fire tests of specimens employing structural low-density concrete, supplemented by further engineering studies by ULC.

Last Updated on 2019-06-20
BXUVC.GuideInfo BXUVC Active 20190620 20190620

The appearance of a company's name or product in this database does not in itself assure that products so identified have been manufactured under UL's Follow-Up Service. Only those products bearing the UL Mark should be considered to be Certified and covered under UL's Follow-Up Service. Always look for the Mark on the product.

UL permits the reproduction of the material contained in the Online Certification Directory subject to the following conditions: 1. The Guide Information, Assemblies, Constructions, Designs, Systems, and/or Certifications (files) must be presented in their entirety and in a non-misleading manner, without any manipulation of the data (or drawings). 2. The statement "Reprinted from the Online Certifications Directory with permission from UL" must appear adjacent to the extracted material. In addition, the reprinted material must include a copyright notice in the following format: "© 2019 UL LLC".