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Building Codes Illustrated: Fire-Resistive Construction
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- 11) 2 basic methods for providing fire-resistive protection are: 2) passive protection works by: 3) active protection like sprinklers works by1) passive & active protection
2) being built into the bldg structure & provides a barrier btwn the structure & fire
3) responding to fire by activation of systems to contain/suppress fire & smoke to allow structure to remain intact for longer time period so occ. can escape - 21) when code provisions otherwise req. active systems, they're not available to: 2) per ch2 "fire-resistance rating" is: 3) a bldg element is defined as:1) offset passive req.'s
2) the period of time a bldg element, component or assembly maintains the ability to confine a fire, continues to perform a given structural function, both
3) a fundamental component of bldg const. table 601, which may/may not be of fire-resistance rated const. & is constructed of mat.'s based on bldg type of const. - 31a-b) summary of 2 purposes of fire-resistive const.:1a) 1st is protection of bldg structure
w/ passive protection directly applied to structural members when used
1b) 2nd is the separation of spaces to prevent the spread of fire or smoke w/in a bldg & spread of fire btwn bldgs - 41) per 202 a fire area is defined as: 2) fire-resistance ratings are based on the performance of various mat.'s & const. assemblies under:1) the aggregate floor area enclosed & bounded by fire walls, exterior walls, fire-resistance-rated horiz. assemblies
2) fire-test conditions as defined by ASTM Int. or Underwriters Labs typ. based on side of assembly fire would be likely to occur - 51) 703.2.5 allows exterior bearing-wall rating req.'s to equal (___) b/c:1) those of nonbearing walls if all factors of fire separations & occ. considered b/c recognize it's main purpose is to prevent fire spread outside of bldg & no pt. in protecting the structure to a higher level than req.'d for enclosing the space
- 61) 703.2.3 assumed that tested assemblies are not (___) via definitions of ASTM E119 or UL 263 which refers to: 2) all designers should assume all assemblies to be (___) when determining (___) b/c:1) "restrained" - the ability of structural members to expand or contract under fire conditions
2) "unrestrained" when determining fire-resistance req.'s b/c restrained assemblies are difficult to prove & outweigh the advg's gainedin reducing quantities of fire-protection mat.'s used - 71) 703.3 allows designers to use several methods to demonstrate: 2) ^ one method uses ratings & code gives table 721 of prescriptive assemblies which gives the designer: 3) table 722 allows the designer to calc the fire-resistance of assemblies by:1) compliance w/ fire-resistive criteria
2) a list of protection measures that can be applied to structural members, floor/roof const., walls to achieve necessary ratings
3) combining various mat.'s - 81) 703.3 allows engineering analysis based on ASTM E 119 or UL 263 to determine a projected fire resistance which means: 2) 703.3 also acknowledges testing measures of 104.11 which allows the:1) rq.'s use of consultant familiar w/ data to predict performance w/out time & expense of full scale fire test
2) bldg official to approve alt ways of meeting the code when new technologies or unusual situations are encountered - 91) 703.4 test criteria clarify that fire tests for rated assemblies may not include: 2) 703.5 defines (___) in terms of test criteria & characteristics that determine it can't be affected by:1) fire suppression, must pass w/out additional cooling from fire suppression water - reiterates req.'s for passive & active protection are to be considered separately
2) noncombustibility - exposure to age, moisture, atmospheric combinations - 101) 703.6 fire-resistance rated glazing when tested w/ ASTM E 119 or UL 263 & complying w/ fire barrier req.'s may be: 2) 703.7 fire walls/barriers/partitions, smoke barriers/partitions, or any other wall that req.'s protected openings shall have:1) used - glazing to have permanent label indicating fire-resistance in minutes
2) a permanent sign/stencil marker in concealed spaces when accessible or not req.'d if can't be concealed -3" text, w/in 15ft of end of wall, 30ft max spacing - 111) 704 req.'s the fire-resistance ratings of structural members & assemblies comply w/ the req.'s for: 2) 704.8 prohibits inclusion of service elements like pips/conduits into the: 3) 704.10 address the protection of structural members located on the:1) type of const. via ch6 & table 601
2) fire production b/c it can conduct heat to structural member & potentially compromise time rating for fire-resistance
3) exterior of a bldg, protection called out in table 601 - req.'d for exterior bearing walls, structural frame, or exterior walls based on fire separation distance - 121) 704.2-3 req. individual structural members like columns or beams to be: 2) 704.6 allows attachment elements to structural members like reinforcing ties to: 3) ^ secondary members can be fire-protected by:1) fully protected on all sides for entire length if they are req.'d to have a fire-resistance rating (see code for det.)
2) be closer to the surface of fire protection than thickness req.'d for main members
3) horiz. assembly like a ceiling complying w/ 711 - 131) 704.2 req.'s full height of column to be: 2) 704.13 clarifies req.'s for:1) protected, even its connection to beams/girders or if extends through a rated ceiling
2) sprayed fire-resistant mat.'s (SFRM) - typ. applied to steel members, rating dependent on thickness, cannot have cracks, delamination, or anything that lets a fire in - 141) 704.9 req.'s (___) for elements w/ SFRM subject to damage extending a height of: 2) 704.4.1 allows studs & boundary elements like side of wndw that are integral to load-bearing wall of light-frame const. to have req.'d fire-resistance rating provided by:1) impact protection extending 5ft abv floor if SFRM can be damaged & knocked off element
2) the membrane protection furnished for the load-bearing wall - 151) 704.5 permits the encapsulation of an entire truss assembly w/: 2) 704.6 permits attachments to structural members like: 3) 704.7 allows stirrups & spiral reinforcement in a:1) fire-resistive mat.'s if assembly has been tested or on test calcs (this can also be construed to apply fire protection directly to individual truss members)
2) lugs & brackets to w/in 1" of fire protection surface
3) masonry or concrete structural member to project no more than 1/2" into the protection - 161) 704.11 allows the bottom flanges of lintels & shelf angles to be:1) left unprotected when spanning 6'-4" or less or not part of primary structural frame which allows lintel over pair of 3ft doors
- 17EXTERIOR WALLS 1) 705 is the relationship to the property line of exterior walls & openings w/in & projections from the walls, it should be read in conjunction w/:1) w/ 1406 which governs the use of combustible mat.'s on exterior walls, 1021 for exterior egress balconies, & 1027 for exterior egress stairs
- 18PROJECTIONS 1) 705.2 governs the extent of allowable projections according to their relationship: 2) projections of walls Type I & II const. to be made of: 3) projection distances are based on:1) to the property line
2) noncombustible const. vs projections of walls of other const. types can be any approved mat.
3) fire separation distance per table 705.2 - 19PROJECTIONS 4) when the fire separation distance is btwn 2ft-3ft projection's min distance: 5) projections aren't allowed when: 6) when fire separation distance is greater than 30ft: 7) for distances from projection to fire separation of 3ft-30ft, projection may be:4) is 2ft
5) fire separation distance is less than 2ft
6) projections can only extend to w/in 20ft of fire separation line
7) 2ft then +8" per foot - 20COMBUSTIBLE PROJECTION PROTECTION 1) unrated projection if more than (___) from fire separation distance 2) combustible projections extending to w/in 5ft of lot line are to be: 3) R-3 & U occ. may have unrated Type V-B projections w/: 4) projections include elements like:1) 5ft
2) min 1hr fire-resistance-rated const., Type IV fire-retardant-treated wood, see 1406.3
3) greater than 5ft fire separation distance
4) eave overhangs, cornices, balconies that extend beyond the exterior wall - 21MULTI BLDGS ON SAME PROPERTY 1) 705.3 assumes an imaginary lines exists btwn bldgs, but not necessarily in the middle so long as: 2) 705.3's intent is to prevent the spread of fire by: 3) 705.5 req.'s that fire-resistance ratings for exterior walls area based on:1) it meets wall protection req.'s on distance assumed
2) radiant heating or convection
3) tables 601-2 to prevent spread of fire btwn properties - 221) 705.5 explains when a bldg is >10ft from property line the fire exposure is assumed to be from: 2) ^ when a bldg is 10ft or less to property line, fire exposure assumed to be: 3) multi bldgs on same lot may be treated as portions of a single bldg if:1) the inside
2) from either inside or outside the bldg b/c another bldg may be built on the lot line of adj property
3) w/in the limits specified in ch5 for intended occ. - 23FIRE RESISTANCE RATINGS 1) 705.6 the exterior wall is to extend to: 2) structural elements that brace the exterior wall & located outside of the plane of the wall must conform to tables: 3) 705.5 specifies exterior walls having a fire-separation distance >10ft be rated for: 4) ^exterior walls of 10ft or less be:1) the height req.'d by 705.11 (parapets)
2) 601 for structural elements & 602 for wall ratings
3) exposure to fires from the inside
4) rated for exposure to fire from both sides - 24OPENINGS 1) equation 7-2 in 705.8 is to determine # of openings allowable given the relationship of protected vs unprotected openings under the site & bldg conditionsAp/ap + Au/au
- 251) (other than group-H) exceptions to 705.8.1 allow unlimited unprotected openings in 1st floor of exterior walls if: 2) if openings in adj stories are w/in 5ft of ea. other. & lower one isn't protected by 1hr rating/> 705.8.5 req.'s:1) exterior walls face public st & have fire-separation distance of 15ft or face an unoccupied space 30ft wide w/ access to fire lane
2) they're separated vert. min 3ft by a 1hr assembly rated for both sides fire exposure or by a horiz. flame barrier that extends 30" beyond exterior wall (req.'s don't apply to bldgs 3 stories/<, w/ sprinklers, open pkg garages) - 26VERTICAL EXPOSURE 1) 705.8.6 req.'s that openings have approved: 2) opening protectives aren't req.'d where the roof has a min rating of: 3) bldgs on same lot & considered portions of one bldg aren't req.'d to:1) 3/4hr min fire-rated protectives if
1a) >15ft vert. abv the roof of an adj structure on the same lot
1b) w/in a horiz. fire distance of 15ft of adj structure
2) 1hr & entire length of structural spans supporting roof have rating of 1hr
3) comply w/ that section - 27PARAPETS 1) the purpose of parapets is to: 2) typ parapets are to extend at least (___) abv the roof & be of const. type:1) impede the spread of fire from one bldg to another by providing a barrier to fire & radiant heat transfer if a fire breaks through a roof membrane
2) 30" abv roof / same const. type as wall - 28EXCEPTIONS TO PARAPETS 1) the wall satisfies the fire-separation distance criteria based on table 602 2) the bldg area doesn't exceed 1,000sf on any floor 3) the roof const. is entirely noncombustible or of at least 2hr fire-resistive const. 4) the roof framing is protected against fire exposure from the inside5) in resi occ. a fire barrier is provided by sheathing the underside of the roof framing, or is of noncombustible mat. for 4ft back from roof/wall intersection & entire bldg has a Class C or better roof covering
6)705.8 allows the wall to have 25%/+ of its openings unprotected due to the bldg's location from a property line - 29ROOF/CEILING FRAMING PARALLEL TO WALL 1) 1hr rated exterior wall 2) no openings are permitted w/in 5ft of fire-resistance-rated exterior walls in groups-R & M & 10ft separation req.'d for other occ.3) roof covering to be Class B min
4) 1hr rated roof/ceiling framing parallel to exterior wall
5) ^ for #4 - 4ft min for groups-R & M & 10ft for other occ. - 30ROOF/CEILING FRAMING NOT PARALLEL TO WALL 1) 1hr rated exterior wall2) entire span of roof/ceiling framing must be of not less than 1hr fire-resistance-rated const.
- 31FIRE WALLS 1) 202 defines a fire wall as: 2) a fire wall can only perform function if:1) a fire-resistance-rated wall w/ purpose to restrict the spread of fire
2) the wall extends cont. from the bldg fnd. to or through the roof w/ sufficient structural stability to withstand collapse if const. on either side of it collapses - 32STRUCTURAL STABILITY 1) 706.2 req.'s that a fire wall have a structural configuration that allows: 2) ^walls constructed per (___) are deemed compliant 3) 706.3 req.'s fire walls to be constructed of (___) & of (___) in Type V:1) for structural collapse on either side while the wall stays in place for time req.'d by the fire-resistance rating
2) NFPA 221, also using a double wall is easy way to comply
3) noncombustible mat.'s / Type V can be of fire-protected combustible const. - 33FIRE-RESISTANCE RATINGS 1) 706.4 bases the req.'d fire-resistance ratings of fire walls on: 2) 706.5 specifies fire walls are to be cont. horiz. from:1) occupancy, & for most the fire walls are req.'d to have 3hr ratings, but 2hr ratings ok in some Type II or V occ., always most stringent req.'s to be used
2) exterior to exterior wall & extend min 18" beyond exterior surface of exterior wall to provide barrier to heat/flame propogation - 341) 706.1 considers ea. portion of a bldg completely separated by one or more fire walls to be: 2) if fire wall is located on property line & considered a party wall, it's not allowed: 3) per NFPA 221 a double wall w/ min clearance btwn, ratings of ea. wall can:1) a separate bldg
2) to have openings
3) have ratings added together to = total needed for req.'d rating - 351) a fire wall may terminate at the interior surface of exterior sheathing if: 2) rated protection may be provided by exterior wall const. w/ resistance rating: 3) 706.5 also allows fire wall to end at interior surface of noncombustible exterior sheathing if: 4) exterior wall intersections don't need fire protection when:1) rated protection forms a "T" & extends a horiz. distance of at least 4ft
2) of min 1hr or noncombustible mat.'s
3) the bldg on ea. side of fire wall is protected w/ auto sprinkler system
4) intersections at fire walls form an angle =/> 180deg - 361) opening protection criteria of 705.5 & 705.8 are to be applied to an exterior wall that forms: 2) 706.5.2 req.'s fire walls to extend to outer edge of horiz. projections when: (^3 exceptions to this req., see next card)1) an angle of <180deg w/ a fire wall intersection
2) they are w/in 4ft of fire wall (balconies, roof overhangs, etc) - 37EXCEPTIONS TO PROJECTIONS ADJ TO FIRE WALLS 1) the extension isn't req.'d when horiz. projecting elements have no concealed spaces &: 2) if noncombustible horiz. projections have concealed spaces:1) exterior wall behind & blw projection is min 1hr rated const. for distance not less than depth of projection on ea. side of fire wall, & openings in exterior wall must be rated 3/4hr
2) a 1hr rated wall must extend through the concealed spaces & same as additional req.'s to #1 abv - 38EXCEPTIONS TO PROJECTIONS ADJ TO FIRE WALLS 3) if combustible horiz. projections have concealed spaces, the fire wall must:3) extend through the concealed spaces to the outer edges of the projections, & additonal req.'s to # 1-2 previously
- 39VERTICAL CONTINUITY 1) 706.6 req.'s fire walls be continuous vert. from bldg: 2) roof const. is to be made of mat.'s: 3) presume fire projection of roof const. extends a min of 4ft on ea. side of fire wall when framing is: 4) ^assume the whole span when framing is:1) fnd. to a pt. at least 30" abv adj roofs
2) that are noncombustible, fire-retardant treated wood, have fire-resistive mat.'s applied on inside to protect framing
3) parallel to the wall
4) perpendicular to fire wall - 401) when a roof slope is 2:12 or more, the fire wall is to project abv: 2) exceptions to 30" extension abv roof when framing is parallel is: 3) exceptions to 30" extension abv roof when framing is perpendicular is:1) a pt. 30" abv a pt. measured 4ft laterally from the top of the wall
2) not less than class-B roof, framing needs 1hr rating w/in 4ft of fire wall, framing to be supported by 1hr rated bearing walls/columns & beams, no openings w/in 4ft of fire wall, fire wall needs 2hr rating
3) 1hr rating of entire span of framing, noncombustible roof sheathing/sim., no openings w/in 4ft of fire wall, not less than class-B roof - 41—