2SequencingInterior finishing begins when the “shell” of the building is sufficiently weatherproof to protect the interior.Mechanical, Electrical and Plumbing, (this may also include fire suppression systems)Vertical runs through a building are typically accommodated by the use of shaftsHorizontal runs through a building are typically placed in raceways or chases
3Sequencing, (continued) Full height partitions and smoke partitionsPartitions “tight to deck”Fire stoppingJoint covers – building separation jointsFire safing – perimeter of floor slab
7Interior Finish Systems Interior finish systems are selected based upon a number of criteria:AppearanceDurabilityAcoustic CriteriaFire Criteria
8Acoustic CriteriaInterior finish materials have an effect upon interior sound quality: noise levels, listening conditions and sound transfer from space to space. The sound transmission is qualified by two measurements:STC – Sound Transmission ClassandITC – Impact Transmission Class
9Acoustic Criteria STC – Sound Transmission Class Measure of sound wave vibrations transferred through the membrane of a wall. STC rating may be reduced by partition details such as dampening clips and resilient mountings that reduce the transfer of vibration from the collection panel through the wall, (typical), assembly or by the addition of sound absorbing insulation, (typically mineral batts), in the wall cavity.ITC – Impact Transmission ClassMeasure of transmission of impact generated noises through a floor/ceiling assembly.
10Acoustic IsolationConstruction methodsSolid construction
12Fire CriteriaThe code develops requirements for interior finishes with respect to both combustibility and flame-spread.Combustibility is the surface burning characteristics of a material, and is described using two criteria: the flame-spread rating and the fuel-contributed rating.
13CombustibilityThe Steiner Tunnel test measures both the flame spread and the amount of fuel contributed by the material as well as the amount of smoke developed.Flame-spread rating is a measurement of how fast fire moves across the surface of a materialFuel-contributed rating indicates the amount of combustible substances in the materialSmoke developed rating classifies the material by the amount of smoke given off when it burns
14Fire-Resistance Requirements Interior wall and ceiling finish requirements are governed by occupancy classification in the IBC, table 803.4, (page 797 in the text)Sprinklered vs. UnsprinkleredVertical exits and passagewaysExit access corridorsRooms and enclosed spaces
15Fire-Resistance Requirements Class A materials: flame-spread ratings lie between 0 and 25Class B materials: flame-spread ratings between 26 and 75Class C materials: flame-spread ratings between 76 and 200.Smoke-developed ratings may not exceed 450 for any of the three classes.
16Fire-Resistance Requirements The scale of the flame-spread ratings is somewhat arbitrary: cement-asbestos board has a value of 0 while red oak has a value of 100.Trim materials are removed from application if their total area does not exceed 10% of the total wall and ceiling area of a room.
17Fire Resistance Ratings Fire barriers: a building assembly that meets the required fire resistance rating for separation of occupancies.Fire walls separate buildings: where the maximum allowable area for a given occupancy is exceeded, multiple buildings may be used.
18Fire Resistance Ratings, (continued) In order to achieve a given fire resistance rating, an assembly is tested in a furnace and subjected to the structural load for which it is designed according to:1770° at one hour and 2000° after four hoursIn order to achieve the fire resistance rating in hours, the assembly must:Safely carry the design load, (structural failure)Must not develop any openings that would permit smoke or gases to penetrate the assemblyMust insulate sufficiently against heat to maintain surface temperatures on the side away from the fire within specified levels.
19Fire Resistance Ratings, (continued) Walls and partitionsMust also pass the “hose test”: a duplicate assembly is subjected to half the fire rated exposure of the original tested part and then subjected to the calibrated stream of a fire hoseThis simulates the behavior of an assembly subjected to a fire hose during an actual fire.
20Fire Resistance Ratings, (continued) PenetrationsOpenings in rated ceiling, floor and wall construction are restricted in size and must be protected against the passage of fireFire rated doors and framesFire dampersFire stops
26PenetrationsStructurally reinforced penetration through wall assembly
27Cost First Cost: Life-cycle cost Installed cost of the finish Of paramount importance when the budget is tight or the expected ownership of the lifespan of a building is shortLife-cycle costCost that includes the first cost, but also includes the expected lifetime of the finish, maintenance, fuel costs, monetary inflation and the replacement cost of the finish.Of paramount importance when the building owner expects to maintain ownership over an extended period of time.
28Interior Walls and Partitions Fire WallsShaft WallsFire BarriersSmoke PartitionsSome additional rated assembliesExit access: corridors and egress stairsDwelling unit separations
29Interior Walls and Partitions Partition WallsNon-bearing partition walls
30PlasterTerm typically applies to “gypsum” plaster, but may also be applied to other systems, including stucco.Gypsum is quarried, crushed, dried and then ground into a fine powder; then heated to 350° F. in a process called “calcining”Product is rehydrated and is able to re-crystallize quickly.
31CalcinationWhen a gypsum building component is subjected to fire, a thin surface layer is calcined and disintegratesIn the process, this layer absorbs heat and gives off steam, both of which have a cooling effect on the fire.Slow process: thin layer by layer
32Plaster and Plaster Systems Gypsum plasterGauging plasterKeenes cementMolding plasterLime and Portland Cement PlastersFinish limePortland cement lime - stucco
33Plaster Systems 2-coat: requires a rigid lath substrate Brown coatFinish coat3-coat: preferredScratch coat
34Veneer Plaster Veneer plaster board, (“blue board”) Plaster is applied to a specially prepared gypsum board in two successive layersThe first thin “veneer” coat is followed immediately by a “skim” coat that is then troweled to the desired finish texture
36Gypsum Board Types Gypsum board Water-resistant gypsum board Type-X: reinforced with glass fibers, when exposed to a severe fire, the fibers hold the calcined gypsum in place to continue to act as a barrier to fire.Foil-backed: includes an integral vapor retarder in exterior wall assemblies
37Gypsum Board, (continued) Types, (continued)Type-C: a proprietary version of Type-X, typically a thinner application of Type-C may be used instead of Type-X to achieve the same protection.Coreboard: 1” thick panel used in shaft applications, (24” panels rather than 48”)High Impact: 5/8” Type-X panel with polycarbonate film bonded to the back.
38Gypsum Board, (continued) Typical thicknesses:¼”: used for backing applications and in multiple layers to achieve tight radius curves5/16”: modular construction to reduce shipping weight½”: the most common, used where joist or stud spacing is 24” or less on center5/8”: also limited to joist or stud spacing is 24” or less on center, often used for additional stiffness or fire rating¾”: Type-X can achieve a 2-hour rating with ¾” on one side of the partition, only.
39Gypsum Board Partition Systems 1-hour partition1-hour partition with an STC of 60-642-hour partition4-hour partition(page 832)
40Specifying Gypsum Board Gypsum board wall finishes have standardized levels of finish that are included in the drawing specifications:Level 0: attached boards only, no tapeLevel 1: joints covered in tape set in joint compoundLevel 2: a finish coat of compound over the tape and accessories, (garages, warehouses)Level 3: a second coat of compound, (prior to textured coating)Level 4: a third coat, (flat paints, light wallcoverings)Level 5: skim coat