Fire-resistance designs documented in approved sourcesThe definition alert boxes in this chapter contain words that may have a slightly different meaning in the world of building construction. They are located throughout this chapter; look at them, read them, and know them. They are here to help you.
The materials that I describe in this chapter for fire resistance will conform to the requirements of this chapter in your code book. The fire-resistance rating of building elements is determined in accordance with test procedures that are made by ASTM E 119 or in accordance with your local code. If you have materials, systems, or devices that have not been tested as part of a fire-resistance-rated assembly, but are incorporated into the assembly, you must show sufficient data or information to the building official that the required fire-resistance rating is not reduced. All of the building materials and methods used in your construction that produce joints and penetration in fire-resistance-rated buildings cannot reduce the required fire-resistance rating except for one condition. When you are determining the fire-resistance rating of outside walls, compliance with the ASTM E 119 data for unexposed surface temperature rise and ignition of cotton waste, because of flame or gases, is only required for the time period that corresponds to the required fire-resistance rating of an outside nonbearing wall that has the same fire separation distance, and must be in a building of the same group.
!Definition alert |
Annular space: The opening around the penetration item. |
If inside walls of a building or structure are not proportioned or even, then they have to be tested with both faces of the walls exposed to the furnace and the assigned fire-resistance rating has to be the shortest duration that you get from the two tests that you conduct in agreement with ASTM E 119. If your evidence is given to the building official and shows that the wall was tested with the least fire-resistant side exposed to the furnace, it is the code officer’s discretion for approval.
Combustible components such as aggregates are permitted in gypsum and cement concrete mixtures approved for fire-resistance-rated construction. Any approved element or admixture (the product of two substances mixed together) is allowed in assemblies if the tested assembly meets the fire-resistance test requirements. These assemblies that are tested under the ASTM E 119 cannot be considered restrained unless the evidence that you present is in accordance with ASTM E 119 approved by the building official. The following methods are alternatives for determining fire-resistance rating, but as I said, they must conform to ASTM E 119 and be approved by your building official.
!Definition alert |
Fire-resistance rating: The period of time a building element, component, or assembly maintains the ability to confine a fire, continues to perform a given structural function, or both, as determined by the tests, or the methods based on tests, as described in this chapter. |
Fire-resistance designs documented in approved sources
Prescriptive designs of fire-resistance-rated building elements as approved in this chapter
Calculations in accordance with this chapter
Engineering analysis based on comparing building element designs that have fire-resistance ratings determined by ASTM E 119.
There are two types of materials—elementary and composite materials—that are noncombustible; these do not conform to ASTM E 119. Elementary materials that are required to be noncombustible must be tested in accordance with ASTM E 136 and composite materials that have a structural base of noncombustible materials with a surfacing of no more than 0.125 inch thick that have a flame spread index of no more than 50 when tested in accordance with ASTM E 84 will be acceptable as noncombustible materials.
Exterior walls are walls, bearing or nonbearing, used as an enclosing wall, but cannot be a fire wall and have a slope of 60 degrees or greater with the horizontal plane. This section will include moldings, eave overhangs, outside balconies, and similar projections that extend beyond the floor area
!Definition alert |
Horizontal assembly: A fire-resistance-rated floor or roof assembly of materials designed to restrict the spread of fire in which continuity is maintained. |
|
Projections from walls that are Type III, IV, or V construction can be of any approved material. With the exception of Type V construction, which is allowed for R-3 occupancies, all combustible projections that are located where openings are not allowed or where protection of openings is required must have at least a one-hour fire-resistance-rated construction. |
and must comply with this section. Outside balconies and outside stairways that have exits must comply with the code. There are two methods that you must put in place to determine the allowable distance that your walls may jut out. The method that allows for the least amount of distance will be the one that you must use. These methods are: A point one-third the distance to the lot line from an assumed vertical plane located where protected openings are required in accordance with this chapter or more than 12 inches into areas where openings are prohibited. If the building or structural wall projections are from Type I or Type II construction they have to be made of materials that are noncombustible or combustible as allowed by code exceptions.
Outside walls have protected and unprotected openings. These openings are required to be vertically separated so that they are protected against fire spread on the outside of the buildings if the openings are within 5 feet of each other horizontally, and the opening in the lower story is not a protected opening with a fire protection rating of no less than ¾ hour. But, you must also have the openings vertically separated at least 3 feet by spandrel girders or outside walls that have a one hour fire-resistance-rating. If not, you have to install flame barriers that extend at least 30 inches horizontally beyond the outside wall. Please note that whether you choose spandrel girders or flame barriers, a one hour fire-resistance rating is required. Exceptions to this are as follows:
This section does not apply to buildings that are three stories or less in height.
This section does not apply to buildings that are fully equipped with an automatic sprinkler system, but it must be throughout the whole building.
This section does not apply to parking garages.
For buildings that are located on the same lot, opening protectives that have a fire-protection rating that is less than ¾ hour must be in every opening that is less than 15 feet vertically above the roof of the building that is next to it within 15 feet of the wall where the opening is located. But if the roof construction has a fire-resistance rating no less than one hour with a minimum distance less than 10 feet then you can disregard the above. The International Building Code requires that all outside walls include parapets, which are walls placed at the edge of a roof. There are certain conditions in which a parapet does not need to be added to an outside wall:
The wall is not required to be fire-resistance-rated because of fire separation distance.
The building’s area is not more than 1000 square feet on any floor.
Walls that end at roofs that are less than two-hour fire-resistance construction or if the roof, this includes the deck and supports, is made entirely of noncombustible materials.
One-hour fire-resistance walls that end at the underside of the roof, deck, or slab, if the following needs are met:
– Roof and ceiling frames cannot be less than one-hour fire-resistance with a width of 4 feet for Groups R and U and 10 feet for all other occupancies.
– Roof and ceiling elements that are not parallel to the wall, the entire span of framing and supports cannot be less than one-hour fire-resistance construction.
– Openings in the roof cannot be located within 5 feet of any one-hour fire-resistant outside wall for Groups R and U and 10 feet for all other occupancies.
– The entire building must be provided with a roof covering that is no less than Class B.
Groups R-2 and R-3 that are covered with a Class C roof covering must have outside walls that end at the underside of the roof sheathing in Type III, IV, and V construction provided that the following conditions are met:
– The roof or deck is constructed of noncombustible materials that are approved or made of fire-retardant wood with a distance of 4 feet.
– The roof is protected with 0.625-inch Type X gypsum board directly beneath the roof or deck. The supports of the roof must have a minimum of 2-inch ledgers attached to the sides of the roof framing with a distance of 4 feet.
– The wall is allowed to have at least 25 percent of the outside walls containing unprotected openings.
Parapets must have the same fire-resistant rating as other construction of any outside wall. They also must be noncombustible from 18 inches from the top downward (this includes counterflashing and coping materials). The code also requires that the parapet is not less than 30 inches above the point of the roof and wall intersection. And, the parapet must extend to the same height of the roof within fire separation distance, but in no case should the height be more than 30 inches. With any rule or code in the International Code Book, if you have any questions, please consult a building official.
|
Any windows in outside walls that are required to have protected openings must comply with this chapter; other openings have to be protected with fire doors. Opening protectives are not required if the building is protected throughout with automatic sprinkler systems or approved water curtains, and joints that are made in outside walls are allowed to have unprotected openings. |
CODE UPDATE |
Fireblocking consists of materials installed to resist the free passage of flame to other areas of the building through concealed spaces. |
Each portion of a building that is separated by one or more fire walls must be considered as a separate building. The extent and the location of the fire walls have to provide a complete separation. Wherever a fire wall separates occupancies you must follow the strictest requirements. This includes any wall located on a lot line between buildings that are adjacent to each other or is adapted for joint service, and must be constructed as a fire wall. Fire walls have to be constructed with the same fire conditions as the rest of the building in regards to duration of time. All fire walls, with the exception of Type V construction, have to be made of approved noncombustible materials.
Fire walls must be continuous from outside to inside walls and must extend at least 18 inches beyond the outside surface walls. Exceptions to this rule are found below:
Fire walls are permitted to end at the inside surface of combustible outside siding provided that the outside walls have a fire-resistance rating of at least one hour for a horizontal distance of at least 4 feet on both sides of the fire wall. Any openings with outside walls have to be protected by opening protectives that have a rating not less than ¾ hour.
Fire walls are permitted to end at the inside surface of a non-combustible outside casing where the buildings on each side of the fire wall are protected by an automatic sprinkler system.
Exterior or outside walls, at the point of intersection, must have, on both sides, a one-hour fire rating with ¾ hour opening protection. The rating must extend a minimum of 4 feet on each side starting from the intersection to the outside all. If such walls form an angle equal to or greater than 180 degrees they do not need outside wall protection. Fire walls must extend to the outer edge of horizontal projections such as balconies, roof overhangs, canopies, and other similar projects that are within 4 feet of the fire wall. There are a few exceptions in regards to these projections that I will explain in the following list:
Horizontal projections without concealed spaces, provided that the outside wall behind and below the projection has no less than a one-hour fire rating for a distance that is not less than the depth of the projection on either side of the fire wall. These openings with outside walls have to be protected by openings with a fire protection rating of ¾ hour; nothing less.
Noncombustible horizontal projections with concealed spaces providing a minimum one-hour rated construction, extending through the concealed space. The wall is not required to extend under the projection and the openings within the outside walls must be protected by opening protectives that have a fire rating of ¾ hour; nothing less.
For combustible horizontal projections with concealed spaces, the fire wall only needs to extend through the concealed space to the outer edges of the projections, and again, a one hour fire rating of ¾ hour is required.
Fire walls must have vertical continuity, meaning fire walls have to extend from the foundation to an ending point at least 30 inches above both adjacent roofs. However, two hour fire-rated walls will be permitted to end at the underside of the roof, deck, or slab if the lower roof within 4 feet of the wall has a one-hour fire rating, openings in the roof are not located within 4 feet of the fire wall, and each building has no less than a Class B roof covering.
CODE UPDATE |
Fire walls, fire barriers, fire partitions, smoke barriers, and smoke partitions are required to be permanently identified with signs or stenciling. |
|
When a fire wall serves as an outside wall for a building and separated buildings that have different roof levels, the wall must end at a point no less than 30 inches above the lower roof level and the outside wall has to be at least 15 feet above the lower roof. These must have a one-hour fire rating construction from both sides of the openings protected by fire assemblies which must be protected by no less than a ¾ hour rating. |
Walls will be permitted to end at the underside of noncombustible roofs, decks, or slabs provided that both buildings have no less than a Class B roof covering. In buildings of Type III, IV, and V construction, walls are allowed to end at the underside of the roof or deck if there are no openings in the roof within 4 feet of the fire wall, the roof is covered with a minimum Class B roof covering, and the roof is constructed of fire-retardant treated wood with a distance of 4 feet on both sides of the wall or the roof is protected with Type X gypsum that is 
inch thick. If the building is located above a parking garage it will be allowed to have fire walls for the buildings located above the garage from the horizontal separation between the parking garage and the buildings.
If a fire wall ends at the base of a roof, the lower roof within 10 feet of the wall has no less than a one-hour fire rating, and the entire length and span of the supports for the roof assembly cannot have a rating of less than one-hour. The lower roof cannot have openings that are located within 10 feet of the fire wall.
Each opening through a fire wall must not be more than 120 square feet, unless both buildings have an automatic sprinkler system throughout. The total width of openings at any floor level cannot be over 25 percent of the length of the wall and openings are not allowed in party walls. Penetrations of fire walls and joints made in or between fire walls must comply with this chapter, and remember; ducts and air transfer openings cannot penetrate fire walls unless they are not on a lot line and comply with this chapter.
Fire barriers must be made of materials that are permitted by the building type of construction and fire-resistance-rated glazing, when tested in accordance with ASTM E 119 shall comply with this section. They have to be labeled or show some type of identification, provided by an approved agency that has the name of the manufacturer, the test standard and the identifier that includes the fire-resistance rating. Exit enclosures, exit passageways, to include horizontal exits, all must comply with the code book.
When outside walls are part of a required fire-rated shaft or exit enclosure they have to be in accordance with the code. Fire barriers must extend from the top of the floor/ceiling assembly below to the bottom of the floor or roof slab or deck above and be securely attached.
Fire barriers must also be continuous through concealed spaces, such as the space above a suspended ceiling. All supporting construction must be protected to allow the required fire rating of the fire barrier supports. Hollow vertical spaces within a fire barrier must be fire blocked at every floor level except that shaft enclosures are allowed to end at a top enclosure when complying with this section.
All outside walls that are used as a part of a required fire-rating enclosure or separation have to comply with this section except for outside walls that are in accordance with code exceptions. Openings in a fire barrier will be protected and will be limited to a maximum aggregate width of 25 percent of the length of the wall having a maximum area of any single opening not being more than 156 square feet. This does apply to openings that have adjoining fire sprinklers throughout and the opening assembly has been tested with ASTM E 119, fire doors serving as an exit.
|
Fire windows that are permitted in atrium separation walls are not limited to the maximum width of 25 percent. All penetrations of fire barriers must comply with this section and penetrations into an exit enclosure or passageway will be allowed, but only when permitted by the code. |
All smoke barriers are required to have a one-hour fire-resistance rating with the exception of smoke barriers that are a minimum of 0.10-inch-thick steel in Group I-3 buildings. Smoke barriers must form an effective casing that is continuous from outside wall to outside wall and from the top of the foundation or floor/ceiling assembly below to the bottom of the floor or roof above. This is to include the connection through concealed spaces, such as those found above suspended ceilings and mechanical spaces. Any supporting construction has to be protected to allow the required fire-resistance rating of the wall or floor supported in buildings other than Type IIB, IIIB, or VB construction. Any smoke barrier with penetrations, joints, and ducts and air transfer openings must comply with this chapter.
Smoke partitions are not required to have a fire-resistance-rating unless required to do so elsewhere in this book. Smoke partitions extend from the top of the foundation or floor to the bottom of the roof to limit the transfer of smoke. All windows and doors, but not to include louvers, must be tested in accordance with UL 1784 before they are considered to be able to resist the free passage of smoke. Any free spaces around penetrating items and in joints must be filled with an approved material to limit the free passage of smoke. This is also true for ducts and air transfer openings, unless installation will interfere with the operation of a required smoke control system.
A horizontal assembly refers to roofs and floors. Floor and roof assemblies that are required to have a fire-resistance rating must comply with this section. All floor and roof assemblies must be made of materials allowed by the type of building construction and the fire-resistance rating of floor and roof assemblies cannot be less than that required by the building type of construction. But what if you have floor assemblies that separate mixed occupancies? In cases such as this, the assembly must have a fire-resistance rating of no less than the minimum required by code, based on the occupancies that are being separated.
If a floor assembly separates a single occupancy into different fire areas, the assembly must have a fire-resistance rating of no less than what was discussed earlier in this chapter. All floor assemblies that separate living spaces in the same building or sleeping units in occupancies in Group R-1, hotel occupancies, R-2, and I-1 must be a minimum of one-hour fire-resistance-rated construction. The only exception to this is dwelling and sleeping units that are used as separation in buildings of Type IIB, IIIB, and VB construction which must have a fire-resistance rating of no less than ½ hour in buildings that are equipped throughout with an automatic sprinkler system.
Where the weight of lay-in ceiling panels that are used as part of fire-resistance-rated floor/ceiling or roof/ceiling assemblies is not strong enough to resist an upward force of 1 lb (48 Pa), you must install wire or another approved device to prevent vertical bowing under such upward force. Access doors are permitted in ceilings of fire-resistance-rated assemblies provided that the doors are tested in accordance with ASTM E 119 as horizontal assemblies and labeled as such. In one-hour-fire-resistance-rated floor construction and one-hour fire-resistance-rated roof construction, neither the ceiling covering nor the floor covering is required to be installed where unusable crawl space or unusable attic space occurs. All assemblies must be continuous without openings, penetrations, or joints except where it is allowed elsewhere in this code.
CODE UPDATE |
Fire barriers shall extend from the top of the floor/ceiling assembly below to the underside of the floor or roof sheathing, slab, or deck above and shall be securely attached thereto. |
Where sleeves are used, they must be securely fastened to the assembly that is penetrated. The space between the item contained in the sleeve and the sleeve itself and any space between the sleeve and the assembly penetrated must be protected. Insulation and coverings on or in the penetrating item must not penetrate the assembly unless the specific material used has been tested as part of the assembly.
Penetration into or through fire walls, fire-barrier walls, smoke-barrier walls, and fire partitions must comply with the following:
In concrete or masonry walls where the penetrating item is a maximum of 6-inch nominal diameter and the area of the opening through the wall is not more than 144 square inches, concrete, grout, or mortar is allowed where it is installed or the full thickness required to maintain the fire-resistance rating or if the material used to fill the annular space will prevent the passage of flame and hot gases that can ignite cotton waste when put up against ASTM E 119 time-temperature fire conditions under a minimum positive pressure difference of 0.01 inch of water at the location of the penetration for the time period that is equal to the fire-resistance rating of the construction penetrated.
All penetrations must be installed as tested in an approved fire-resistance rated assembly.
Penetrations must be protected by an approved firestop system installed and tested in accordance with ASTM E 814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water and must have an F rating of no less than required of the fire-resistance rating.
|
Dissimilar materials such as noncombustible penetrating items must not connect to combustible items beyond the point of firestopping unless it can be demonstrated that the fire-resistance integrity of the wall is maintained. |
Where walls or partitions are required to have a fire-resistance rating, recessed fixtures cannot be installed in a way that will reduce the required fire resistance, except for the following: Membrane penetrations of a maximum two-hour fire-resistance-rated wall and partition by steel electrical boxes that are not more than 16 square inches in area, but only if the total area of the openings through the membrane is not more than 100 square inches in any 100 square feet of wall area. The annular space between the wall membranes and the box cannot be more than 
inch.
Steel electrical boxes on opposite sides of walls or partitions must be separated by one of the following:
By a horizontal distance of no less than 24 inches
By a horizontal distance of not less than the depth of the hole in the wall where the hole is filled with cellulose loose-fill, rockwool, or slag mineral wool insulation
By solid fireblocking
By protecting both outlet boxes with listed putty pads
By any other listed materials and methods
Membrane penetrations by listed electrical boxes of any material, and the boxes have been tested for use in fire-resistance-rated assemblies
Boxes are installed in accordance with the instructions that are included in the listing
The space between the wall and the box cannot be more than inch unless listed otherwise
Boxes on opposite sides of the wall or partition must be separated according to the list above.
Joints that are installed in or between fire-resistance-rated walls, floors, or floor/ceiling assemblies, and roofs or roof/ceiling assemblies must be protected by an approved fire-resistant joint system designed to resist the passage of fire for a time period that is not less than the required rating. The void or space created at the intersection of a floor/ceiling assembly and an outside curtain wall assembly must be protected in accordance with this section. Fire-resistant joint systems will not be required for joints in all of the following locations:
Floors within a single dwelling unit
Floors where the joint is protected by a shaft enclosure
Floors within atriums where the space adjacent to the atrium is included in the volume of the atrium for smoke control purposes
Floors within malls
Floors within open parking structures
Mezzanine floors
Walls that are allowed to have unprotected openings
Roofs where openings are permitted
Control joints that are not more than a maximum width of 0.625 inch (15.9 mm) and tested in accordance with ASTM E 119.
Fire-resistant joint systems must be securely installed in or on the joint for its entire length so it will not dislodge, loosen, or otherwise impair its ability to accommodate expected building movements and to resist the passage of fire and hot gases. Fire-resistant joint systems must be tested in accordance with the requirements of either ASTM E 1966 or UL 2079. Non-symmetrical wall joint systems must be tested with both faces exposed to the furnace, and the assigned fire-resistance rating must be the shortest time from the two tests.
A separate fan system shall be used for each elevator hoistway. |
When evidence is furnished to show that a wall was tested with the least fire-resistant side exposed to the furnace, and the building official agrees, then the wall does not need to be subjected to tests from the opposite side. For outside walls with a horizontal fire separation distance more than 5 feet, the joint system must be required to be tested for inside fire exposure only.
Where fire-resistance-rated floor or floor/ceiling assemblies are required, empty spaces created at the intersection of the outside curtain wall assemblies and such floor assemblies must be sealed with an approved material or system to prevent fire from spreading around the inside. These materials or systems must be securely installed and be capable of preventing the passage of flames and hot gases that are hot enough to ignite cotton waste when subjected either to ASTM E 119 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch of water column or installed as tested in accordance with ASTM E 2307 for the time period at least equal to the fire-resistance-rating of the floor assembly.
Height and fire-resistance requirements for curtain wall spandrels must comply with the section of this chapter that does not require a fire-resistance-rated spandrel wall. Fire-resistant joint systems in smoke barriers must be tested in accordance with the requirements of UL 2079 for air leakage. The air leakage rate of the joint must not be more than 5 cfm per lineal foot of joint at 0.30 inch of water for both the immediate surrounding area temperature and elevated temperature tests.
The fire-resistance rating of structural members and assemblies must comply with the requirements for the type of construction and cannot be less than the rating required for the fire-resistance-rated assemblies supported except for fire barriers and partitions and smoke barriers that were provided earlier in this chapter. Protection of columns, girders, trusses, beams, lintels, or other structural pieces that are required to have a fire-resistance rating must also comply with this section. Any of these that are required to have a fire-resistance rating and that support more than two floors or one floor and roof, or support a load-bearing wall or a non-load-bearing wall more than two stories high, must be individually protected on all sides for the full length with materials having the required fire-resistance rating.
King studs and boundary elements that are integral elements in load-bearing walls of light-framed construction must be permitted to have required fire-resistance ratings provided by the covered protection provided for the load-bearing wall. Where columns need a fire-resistance rating, the entire column, including its connections to beams or girders, must be protected.
Where a column extends through a ceiling, fire resistance of the column must be continuous from the top of the foundation or floor/ceiling assembly below through the ceiling space to the top of the column. The required thickness and construction of fire-resistance-rated assemblies enclosing trusses must be based on the results of full-scale tests or combinations of tests on truss components or on approved calculations based on such tests that satisfactorily demonstrate that the assembly has the required fire resistance. The edges of lugs, brackets, rivets and bolt heads that are attached to structural members must be allowed to go over one inch of the surface of the fire protection.
The thickness of protection for concrete or masonry reinforcement must be measured to the outside of the reinforcement except that stirrups and spiral reinforcement ties are allowed to project no more than 0.5 inch into the protection. Any and all pipes, wires, conduits, ducts, or other service facilities must not be embedded in the required fire protective covering of a structural member that is required to be individually encased.
Any place where the fire protective covering of a structural member is subject to impact damage from moving vehicles, the handling of merchandise or other activity, the fire protective covering must be protected by corner guards or by a substantial jacket of metal or other noncombustible material to a height that will provide full protection, but no less than 5 feet from the finished floor.
CODE UPDATE |
Penetrations in smoke barriers must be tested for air leakage. |
CODE UPDATE |
A listed smoke damper designed to resist the passage of smoke shall be provided at each point a duct or air transfer opening penetrates a fire wall that serves as a horizontal exit. |
Exterior structural members that are located within the outside walls or on the outside of a building or structure must be provided with the highest fire-resistance rating as determined in accordance for the type of building element based on the type of construction of the building, for outside bearing walls and as required for outside walls based on the fire separation distance.
Fire protection is not required at the bottom flange of lintels, shelf angles, and plates spanning no more than 6 feet whether part of the structural frame or not, and from the bottom flange and not part of the structural frame regardless of span.
Fire-resistance ratings for the isolation system must meet the fire-resistance rating required for columns, walls, or other structural elements in which the isolation system is installed in accordance with code requirements. Isolation systems that are required to have a fire-resistance rating must be protected with approved materials or construction assemblies designed to provide the same degree of fire resistance as the structural element in which it is installed when tested in accordance with ASTM E 119. With this isolation protection system applied to isolator units it must be capable of preventing the transfer of heat to the isolation unit in such a manner that the required gravity load-carrying capacity of the isolator unit will not be damaged after exposure to the standard time-temperature curve fire test as in ASTM E 119 for no less than required for the fire-resistance rating of the structure element of installation. This isolation system protection applied to isolator units must be correctly designed and securely installed so it does not dislodge, loosen, become damaged, or harm its ability to accommodate the seismic movements for which it is designed.
Any opening protectives that are required by other sections of this code must comply with this section. However, labeled fire-resistance-rated glazing tested as part of a wall assembly in accordance with ASTM E 119 does not need to comply with this section. There are alternative methods for determining fire protection ratings, but they must be based on the fire exposure and acceptance criteria specified in NFPA 252 or NFPA 257. The required fire resistance of an opening protective must be permitted to be recognized by any of these methods:
Designs documented in approved sources
Calculations performed in an approved manner
Engineering analysis based on a comparison of opening protective designs having fire-protection ratings as determined by the test procedures as found in NFPA 252 or 257
Alternate protection methods.
I talked earlier about fire doors and shutter assemblies and the fire ratings for such. These doors do not include side-hinged or pivoted swinging doors that must be tested as well in accordance with NFPA 252 or UL 10C.
|
Doors that are in exit enclosures and exit passageways must have a maximum transmitted temperature end point of no higher than 450°F above the surrounding area at the end of 30 minutes of a standard fire test exposure, but the maximum transmitted temperature rise is not limited in buildings equipped throughout with an automatic sprinkler system. |
This test requires that after five minutes of testing with the NFPA 252 test, the neutral pressure level in the furnace must be at 40 inches (1016 mm) or less above the sill.
There are other types of doors, such as swinging elevator doors, that also must be tested in accordance with NFPA 252 or UL 10B. The pressure in the furnace must be maintained as equal as possible to the atmospheric pressure. Once this is done, the pressure must be maintained during the entire test period. Fire door assemblies that are required to have a minimum fire protection rating of 20 minutes where located in corridor walls or smoke-barrier walls having a fire-resistance rating in accordance with code must be tested in accordance with NFPA 252 or UL 10C without the hose stream test. Listed below are three exceptions to this:
Corridor door assemblies in occupancies of Group I-2 must be in accordance with code regulations.
Unprotected openings must be permitted for corridors in multi-theater complexes where each auditorium has as least one-half of its required exits or exit access doorways opening directly to the exterior or into an exit passageway.
Fire door assemblies must meet the requirements for a smoke and draft control door assembly tested in accordance with UL 1784. Louvers are prohibited. When you are installing smoke doors be sure to follow NFPA 105. In a 20-minute fire door assembly, the glazing material in the door itself must have a minimum fire-protection rating of 20 minutes and must be exempt from the hose stream test. Glazing material in any other part of the door assembly, including transom lites and sidelites, must be tested in accordance with NFPA 257, and includes the hose stream test.
All fire door assemblies, oversized doors, smoke and draft doors must be labeled by an approved agency and must comply with NFPA 80. I will remind you that these types of labels have to be permanently attached to the door or the frame. The label must also show the name of the manufacturer, the name of the inspection agency, the fire rating and, if required, the maximum temperature end point.
Some of you may be using wired glass panels that are found in some fire doors. The codes for these types of doors differ slightly from the ones I mentioned above. Glazing other than wired glass in fire windows must be fire-protection-rated glazing and installed in accordance with NFPA 80. It must be installed in the fixed position or be automatic-closing.
Fire-protection-rated glazing in fire doors that are located in fire walls are prohibited except where used as a horizontal exit. A self-closing swinging door will be permitted to have a vision panel of no more than 100 square inches without a dimension more than 10 inches and they cannot be installed in fire doors that have a 1½ -hour fire protection rating intended for installation in fire barriers, unless the glazing is not more than 100 square inches in area.
All approved fire-protection-rated glazing that is used in fire door assemblies in elevator and exit enclosures must be located sot that there is a clear view of the hallway or entry to the elevator, ramp, or stairway. These too must be labeled as stated above. Fire-protection-rated labels must have one of the following four-part identification: “D–H,” “NH–T,” or “NT–XXX.” The list below provides the meaning of each of these.
“D” indicates that the glazing must be used in fire door assemblies and it meets the fire resistance of the test.
“H” indicates that the glazing meets the hose stream requirements of the test standards.
“NH” indicates that the glazing does not meet the hose stream requirements.
“T” indicates that the glazing meets the temperature requirements.
|
All fire dampers used for hazardous exhaust duct systems must comply with the International Mechanical Code. Assemblies with less than three-hour fire-resistance-rating must have a minimum of 1.5 hour damper rating. And assemblies that have a three or more hour rating must have a minimum of three hour damper rating. |
“NT” indicates that the glazing does not meet the temperature requirements.
“XXX” specifies the fire-protection-rating period, in minutes.
Fire protection rated glazing that is installed in fire doors or fire window assemblies in hazardous locations must comply with the code. Fire doors that are located in common walls that separate sleeping areas in Group R-1 are not required to be automatic or self-closing; always check with your local building official as this is not the rule for all fire doors, and as a reminder, automatic-closing doors must be in accordance with NFPA 80. Below is a list of all doors that must be automatic closing. Also, unless otherwise permitted, all fire doors, either single or side-hinged swinging doors, must have a latch bolt that secures the doors when closed. Glazing in fire window assemblies must comply with the code in regards to fire protection ratings.
Doors installed across a corridor
Doors that protect openings in exits
Doors that protect openings in walls and are capable of resisting smoke
Doors installed in smoke barriers
Doors installed in fire partitions
|
Smoke damper leakage ratings cannot be less than Class II and elevated temperature ratings cannot be less than 250°F. Smoke dampers must close when a smoke detector(s) is activated. In places where a damper is installed within a duct, a smoke detector must also be installed within 5 feet of the damper with no air outlets or inlets in between. If a damper is installed above a smoke barrier door in a smoke barrier, a spot-type detector listed for releasing service must be installed on either side of the smoke barrier door opening. If a damper is installed within an unducted opening in a wall, a spot-type detector listed for releasing service must be installed within 5 feet horizontally of the damper. |
Doors installed in a fire wall
Doors installed in shaft enclosures
Doors installed in refuse and laundry chutes and access and termination rooms
Doors installed in the walls for compartmentation of underground buildings
Doors that are installed in elevator lobby walls of underground buildings
Doors that are installed in smoke partitions.
If your building or structure has installed vertical sliding or vertical rolling steel fire doors for pedestrian use, they must be heat activated or activated by smoke detectors to ensure the safety of the public.
Ducts and air transfer openings that penetrate fire partitions must be protected with listed fire dampers. Occupancies other than Group H do not require a fire partition if the following are met:
The buildings are tenant separation or corridor walls in buildings that are equipped throughout with an automatic sprinkler system and the duct is protected as a through penetration
Tenant partitions in covered mall buildings where the walls are not required by provisions elsewhere in the code to extend to the bottom of the floor or roof deck above
The duct system is constructed of approved materials in accordance with the International Mechanical Code and the duct that penetrates the wall meets the following requirements:
– The duct cannot be more than 100 square inches.
– The duct must be constructed of steel that is a minimum of 0.0217 inch thick.
– The duct cannot have openings that share the corridor with adjacent spaces or rooms.
– The duct cannot terminate as a wall register in the fire-resistance-rated wall.
– A minimum 12-inch-long by 0.060-inch-thick sleeve has to be centered in each duct opening.
– The sleeve will be secured to both sides of the wall and all four sides of the sleeve must have steel retaining angles that are a minimum of 1.5 inches by 1.5 inches by 0.060 inch.
– The retaining angles must be secured to the sleeve and the wall with no. 10 screws.
– The annular space between the steel sleeve and the wall opening must be filled with mineral wool batting on all sides.
A listed smoke damper is designed to resist smoke passing through areas of buildings and is required to be provided at each point that a duct or air transfer opening penetrates a corridor. However please note that smoke dampers are not required when the building has an approved smoke control system in place throughout and they are also not required in corridor penetrations if the duct is constructed of steel that is no less than 0.019 inch thick and there are no openings in use for corridors.
You must also have a smoke damper in place at each duct or air transfer opening penetrating a smoke barrier unless the openings in the duct is a single smoke compartment and constructed of steel. Penetrations by ducts and air transfer openings of a floor or floor/ceiling assemblies or the ceiling covering of a roof/ceiling assembly must be protected by a shaft enclosure that complies with this chapter. In occupancies other than Groups I-2 and I-3, a duct that is constructed of approved materials in accordance with the International Mechanical Code and penetrates a fire-resistance-rated floor/ceiling that connects no more than two stories is permitted without shaft enclosure protection, granted that a listed fire damper is installed at the floor line or the duct is protected.
|
Ducts and air transfer openings constructed of approved materials in accordance with the International Mechanical Code that penetrate the ceiling membrane of a fire-resistance-rated floor/ceiling or roof/ceiling assembly must be protected in a shaft enclosure or a listed ceiling radiation damper that is installed at the ceiling line where the duct penetrates the ceiling of floor/ceiling or roof/ceiling or a ceiling radiation damper that is installed at the ceiling line where a diffuser with no duct attached penetrates the ceiling of a floor/ceiling or roof/ceiling assembly. |
CODE UPDATE |
Sprayed fire-resistant materials shall be identified by density and thickness required for a given fire-resistance rating. |
A duct is permitted to penetrate three floors or less without a fire damper at each floor, provided it meets all of the following requirements:
The duct must be contained and located within the cavity of a wall and must be constructed of steel that is no less than 0.019 inch in thickness.
The duct must open into only one dwelling or sleeping unit and the duct system must be continuous from the unit to the outside of the building.
The duct cannot be more than 4 inches nominal diameter and the total area of the ducts cannot be more than 100 square inches in any 100 square feet of floor area.
The annular space around the duct is protected with materials that prevent the passage of flame and hot gases sufficient to ignite cotton waste when exposed to ASTM E 119 time-temperature conditions under a minimum positive pressure difference of 0.01 inch of water at the location of the penetration for the time period equal to the fire-resistance rating of the construction penetrated.
Grilled openings located in a ceiling of a fire-resistance-rated floor/ceiling or roof/ceiling assembly must be protected with an installed listed ceiling radiation damper.
In combustible concealed spaces fire-blocking and draft-stopping must be installed. Fire-blocking materials must include nominal or standard lumber that is at least 2 inches thick or two pieces of 1 inch lumber with broken lap joints. Other materials can include: one wood structural panel of at least 0.719 inch that has joints backed by another wood structural panel of the same thickness. You may also use gypsum board, cement fiber board, batts or blankets of mineral wool, glass fiber, or any other approved materials. Always check with the building officer or your local code office to obtain approval of your materials in question.
All materials must be securely installed if to be considered for an appropriate fire-block. Loose-fill insulation material cannot be used unless specifically tested in the form and manner intended for use and shown to be an appropriate material that will remain in place and will repel the spread of fire and hot gases.
In walls that are made of double stud, batts and blankets of mineral or glass fiber will be allowed as fire-blocking in walls using parallel rows of studs or staggered studs. Speaking of stud walls and partitions, which include furred spaces and parallel rows of studs, they must be vertically at the ceiling and floor levels or horizontally at intervals that are not more than 10 feet.
Fire-blocking must be provided for the following areas:
Connections between horizontal and vertical spaces that are between the stud walls
Concealed horizontal spaces created by an assembly of floor joists or trusses
Between concealed horizontal and vertical spaces such as soffits and drop and cove ceilings
!Definition alert |
Sleeper: Usually, a wood member embedded in concrete, as in a floor, that serves to support and to fasten the sub-floor or flooring. |
In concealed spaces in stairways between stringers at the top and the bottom of the run
Annular spaces in openings around vents, pipes, ducts, chimneys and fireplaces at ceiling and floor levels. Note: factory-built chimneys and fireplaces must be fire-blocked in accordance with UL 103 and UL 127.
Architectural trim that has concealed spaces of outside wall finish and other outside architectural elements must also have fire-blocking installed where erected with combustible frames, at maximum intervals of 20 feet, so that there are no open spaces more than 100 square feet. If wood furring strips are used, they need to be made of an approved wood that has a natural decay resistance or preservative-treated wood.
Fire-blocking is not required of cornices in single-family homes, however in two-family homes you must install fire-blocking, but only at the line of separation between the two homes. If the framing of the building or structure and the face of the outside wall finish is covered by aluminum that is at least 0.019 inch thick or corrosion-resistant steel with a base metal thickness at least 0.016 inch or any other approved materials, you are not required to install fire-blocking.
In concealed sleeper spaces where wood sleepers are used for laying wood floors on masonry or concrete fire-resistance-rated floors, the space between the floor slab and the bottom of the wood flooring must be filled with an approved material to resist the passage of flame and products of combustion of fire-blocked so that there will be no open spaces under the flooring that will be more than 100 square feet in area.
Any empty spaces must be filled so that they are solid full under permanent partitions and there is no passing under the flooring between adjacent rooms. This includes the joint at each alternate lane and at the ends of each lane in a bowling alley. However, gymnasium floors that are slab-on-grade are not required to have fire-blocking.
Fire-blocking has a “friend” that we must not forget about—draft-stopping. One cannot be without the other. All combustible construction must have draft-stopping installed to sub-divide floor/ceiling assemblies in locations and occupancies that follow. There are several approved materials that you can use for draft-stopping. Any material that you use cannot be less than 0.5 inches. But first, let’s take a look at the required materials that draft-stopping must be made of:
Gypsum board—0.375 inch (9.5 mm)
Wood structural panel—0.375 inch (9.5 mm)
Particle board—1 inch (25-mm), nominal lumber
Cement fiberboard, batts, or blankets of mineral wool or glass fiber, or other approved materials that offer enough support can also be used for draft-stopping.
Now that you know what materials you can use for draft-stopping, I will go into the occupancies in which draft-stopping must in installed. Groups R-1, R-2, R-3, and R-4 all require draft-stopping in certain situations.
Group R-1 must provide draft-stopping in floor/ceiling spaces. Draft-stopping must be provided in Group R-2 buildings with three or more dwelling units, Group R-3 buildings with two dwelling units, and in Group R-4 buildings. Draft-stopping must be located above and in line with the dwelling unit and sleeping unit separations. Draft-stopping must also be installed in attics to sub-divide attic and concealed roof spaces. Draft-stopping is not required in buildings equipped throughout with automatic sprinkler systems as long as the sprinklers are also installed in the combustible concealed spaces. In all other groups, draft-stopping must be installed so that horizontal floor areas are not more than 1000 square feet.
In Groups R-1 and R-2 draft-stopping must be provided in attics, mansards, overhangs, or other concealed roof spaces of Group R-2 buildings with three or more dwelling units in all Group R-1 buildings. Draft-stopping must be installed above, and in line with, sleeping unit and dwelling unit separation walls that do not extend to the bottom of the roof sheathing above. There are three exceptions however that you must be aware of:
In cases where corridor walls provide a sleeping unit or dwelling unit separation, draft-stopping is only required above one of the corridor walls.
Draft-stopping is not required in buildings that are equipped throughout with an automatic sprinkler system, only if combustible concealed spaces are included in the system.
In occupancies in Group R-2 that are not more than four stories in height, the attic space does not need to be subdivided by draft-stops into an area that is not more than 3000 square feet or above every two dwelling units, or whichever is smaller.
Insulating materials that include facings such as vapor retardants and vapor-permeable membranes, similar coverings, and all layers of single and multilayer reflective foil insulations must comply with this section. Flame spread indexes or a smoke-developed index must be determined with ASTM E 84. Any material that is subject to an increase in flame spread index or smoke-developed index beyond the limits of this code because of the age of the material, moisture, or other conditions caused by exposure to the atmosphere for a long period of time are not permitted.
Concealed and exposed insulation when installed in buildings of any type of construction must always have a flame index of no more than 25 and smoke-developed index of no more than 450. This does not apply to buildings of Type III, IV, or V construction regarding the flame spread for facings, coverings, and layers of reflective foil insulation that are installed behind and in contact with the unexposed surface of the ceiling, wall, or floor finish. However, exposed insulation that is installed on attic floors must have a critical radiant flux of no less than 0.12 watt per square centimeter when tested in accordance with ASTM E 970.
Another type of insulation is loose-fill. This type of insulation cannot be heaped in the ASTM E 84 apparatus without a screen or support unless it complies with the flame spread and smoke-developed limits. If the loose-fill insulation that you are using is cellulose it does not have to comply with the frame spread index that is required of CAN/ULC S102.2. But, you need to be aware that loose-fill insulation does have to comply with CPSC 16 CFR, Part 1209, and CPSC 16, Part 1404 when applicable and must be labeled as such. Combustible roof insulation that does not comply with this section can be used in any type of construction, but it needs to be covered with an approved roof covering.
We have completed this chapter and are now ready to move into Chapter 5.
