Fire Inspection and Code Enforcement, 7 th Edition. Chapter 6 Building Construction: Components Inspector II

Transcription

1 Fire Inspection and Code Enforcement, 7 th Edition Chapter 6 Building Construction: Components

2 Today we will Discuss fire walls, party walls, fire partitions, and curtain walls Discuss roof types and coverings Discuss various characteristics of floors 6 1

3 Today we will Describe common characteristics of ceilings. Describe types of stairs and their common components and explain how stairs are protected when used as part of the means of egress. 6 2

4 Purpose of Fire Walls Erected to limit maximum spread of fire Act as an absolute barrier to a fire under conditions of a total burnout on either side Fire-resistance ratings 6 3

5 Fire Wall Construction Types Freestanding Self-supporting and independent of building frame Found in buildings of wood-frame or masonry construction Tied Erected at a column line in a building of steel-frame or concrete-frame construction 6 4

6 Fire Wall 6 5

7 Characteristics of Fire Walls Must extend beyond walls and roofs to prevent radiant heat of flames from igniting adjacent surfaces Subdivide a building into smaller areas so that a fire in one portion of a building is limited to that area and does not destroy entire building (Continued) 6 6

8 Characteristics of Fire Walls 6 7

9 Fire Wall Openings Must be protected by automatic or selfclosing fire doors When ducts for heating, ventilating, and air-conditioning (HVAC) systems penetrate fire walls with a fireresistance rating of 2 hours or more, ducts must be equipped with fire and smoke dampers. 6 8

10 Party Wall Lies on a lot line between two buildings and is common to both buildings Erected to limit maximum spread of fire Frequently function as fire walls and extend through a building from the basement through the roof, capped with a parapet 6 9

11 Fire Partitions and Fire Barriers Interior walls used to subdivide a floor or area of a building Do not qualify as fire walls Fire Partitions Fire Barriers (Continued) 6 10

12 Fire Partitions and Fire Barriers Can be constructed from wide variety of materials When floor area of a building is subdivided with fire-resistive partitions/walls, it is compartmentalized 6 11

13 Enclosure and Shaft Walls Used to encompass vertical openings that extend from floor to floor in a building Purpose Requirements 6 12

14 Curtain Wall Exists when a building is constructed using a structural frame for its main structural support Separates interior environment from exterior (Continued) 6 13

15 Curtain Wall (Continued) 6 14

16 Curtain Wall Construction Must be constructed to resist: Wind Rain Snow (Continued) 6 15

17 Curtain Wall Must control Heat loss Noise transmission Solar radiation Lacks inherent fire resistance (Continued) 6 16

18 Movable Partitions Make it possible to subdivide interior of a building to suit different needs 6 17

19 Roofs Fundamental part of all buildings Primary function Provide protection from weather Can contribute to fire hazard of a building 6 18

20 Roof Types 6 19

21 Trusses Framed structural units made of a group of triangles in one plane Vulnerable to early failure under fire conditions due to reduced mass of components and interdependence of those components 6 20

22 Roof Coverings Provide water-resistant barrier for roof system Type used depends on a number of factors Wood roof shingles and shakes (Continued) 6 21

23 Roof Coverings Asphalt shingles Clay, slate, and cement tiles Metal roof coverings (Continued) 6 22

24 Floor Construction Concrete Terrazzo Clay tiles (Continued) 6 23

25 Floor Construction Wood Brick (Continued) 6 24

26 Floor Supports Steel Wood Masonry 6 25

27 Floor Coverings Carpet Paint Laminated wood Vinyl Ceramic tile (Continued) 6 26

28 Floor Coverings Can conceal actual floor system beneath Flammability Can be increased by floor coverings Codes limit flammability of floor coverings 6 27

29 Floor Penetrations and Openings Must include fire-resistive enclosures Types of openings Ideally, should be enclosed Unprotected opening 6 28

30 Ceilings Do not play a structural role Frequently have a functional role in building Interstitial space can be used as a return-air plenum; fire inspector must ensure that materials are noncombustible or rated for plenum use (Continued) 6 29

31 Types of Stairs Protected or enclosed stairs Part of required means of egress; must provide protection for occupants as they travel to safety Access or convenience stairs Not required to be a part of means of egress system and typically connect no more than two levels 6 30

32 Stair Designs 6 31

33 Stair Components 6 32

34 Stairs Can serve as chimneys to spread smoke and fire Provide a means of escape from all levels of the structure 6 33

35 DISCUSSION QUESTION Why is it important that stairs meant for use as escape routes be as smoke free as possible? 6 34

36 Protected Stairs Enclosed with fire-rated construction depending on building height Generally serve two or more stories and part of the required means of egress Stair enclosures (Continued) 6 35

37 Protected Stairs 6 36

38 Exterior Stairs Open to air Generally protected by limiting or protecting opening in building s outside wall near stairs Enclosed 6 37

39 Fire Escapes Open metal stairs and landings attached to outside of a building Not permitted in new construction May not be able to support required live load created during emergency evacuations or fire suppression operations (Continued) 6 38

40 Fire Escapes 6 39

41 Smokeproof Stair Enclosures Required by building codes under certain circumstances Stair enclosures using either active or passive smoke control Mechanical ventilation system 6 40

42 Unprotected Stairs Not protected from fire and smoke in building they serve Not enclosed with fire-rated construction Allowed in buildings when connecting only two adjacent floors above basement level (Continued) 6 41

43 Unprotected Stairs Can be used as part of an exit system in a two-story building Open stairs Only allowed in building equipped with an automatic sprinkler system in particular occupancies 6 42

44 Summary Many components are incorporated into a building s structural system, as well as a number of systems that enclose the structural components to define a building s limits. (Continued) 6 43

45 Summary Certain components provide access to structures, and others are finished with interior finishes, all of which may or may not contribute to fire spread. (Continued) 6 44

46 Summary Building services may also increase or decrease inherent fire hazards within a building. An inspector must be able to evaluate these building components and determine the level of fire protection provided by them. 6 45