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Ventilation

Ventilation. Intermediate SFFMA Objectives: 8-02.01 – 8-02.05 8Hrs received. SFFMA Objectives Covered. Selecting Place to Ventilate. Ideal situation one with as much information as possible about fire, building, occupancy Many factors have bearing on where to ventilate. (Continued).

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Ventilation

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  1. Ventilation Intermediate SFFMA Objectives: 8-02.01 – 8-02.05 8Hrs received

  2. SFFMA Objectives Covered

  3. Selecting Place to Ventilate • Ideal situation one with as much information as possible about fire, building, occupancy • Many factors have bearing on where to ventilate (Continued) Firefighter I

  4. Selecting Place to Ventilate • Many considerations before ventilating building Firefighter I

  5. DISCUSSION QUESTION Why is it important for ventilation to be coordinated with other operations such as fire attack? Firefighter I

  6. Vertical Ventilation • Opening roof/existing roof openings for allowing heated gases, smoke to escape • Firefighters must understand basic types, designs of roofs (Continued) Firefighter I

  7. Vertical Ventilation • Firefighters must know how roofs in the response areas are constructed (Continued) Firefighter I

  8. Vertical Ventilation — Preincident Inspections • Identify • New construction projects • Existing construction • Use of lightweight building materials • Information that can alert firefighters Firefighter I

  9. Likelihood of Roof Collapse During Vertical Ventilation • Based on • Volume of fire • How long fire has been burning • Type of construction • Level of protection • Load on roof Firefighter I

  10. Responsibilities During Vertical Ventilation — Officer in Charge • Determine it can be done safely, effectively • Consider age, type of construction • Consider location, duration, extent of fire • Observe safety precautions (Continued) Firefighter I

  11. Responsibilities During Vertical Ventilation — Officer in Charge • Identify escape routes • Select place to ventilate • Move personnel, tools to roof Firefighter I

  12. Responsibilities During Vertical Ventilation — Leader on Roof • Ensure roof safe to operate on • Ensure only required openings made • Direct efforts to minimize secondary damage • Coordinate crew’s efforts with firefighters inside building (Continued) Firefighter I

  13. Responsibilities During Vertical Ventilation — Leader on Roof • Ensure safety of all personnel • Ensure team leaves roof as soon as assignment completed Firefighter I

  14. Safety Precautions During Vertical Ventilation • Check wind direction with relation to exposures • Work with wind at back/side to provide protection while cutting • Note existence of roof obstructions/excessive weight on roof (Continued) Firefighter I

  15. Safety Precautions During Vertical Ventilation • Provide secondary means of escape for crews (Continued) Firefighter I

  16. Safety Precautions During Vertical Ventilation • Ensure main structural components not cut while creating opening • Guard opening to prevent personnel falling into it • Evacuate roof promptly when ventilation complete (Continued) Firefighter I

  17. Safety Precautions During Vertical Ventilation • Use lifelines, roof ladders, other means to prevent sliding/falling • Make sure roof ladder (if used) firmly secured over roof’s peak • Exercise caution when working around electric, guy wires (Continued) Firefighter I

  18. Safety Precautions During Vertical Ventilation • Ensure all personnel on roof wear full PPE including SCBA • Keep other firefighters out of range of those swinging axes, operating saws • Caution axe users to be aware of overhead obstructions (Continued) Firefighter I

  19. Safety Precautions During Vertical Ventilation • Start power tools on ground to ensure operation; shut off before hoisting/carrying to roof • Extend ladders 3-5 rungs above roof line, secure ladder • When operating from aerial ladder platforms, floor of platform even with/slightly above roof level (Continued) Firefighter I

  20. Safety Precautions During Vertical Ventilation • Check roof for structural integrity before stepping on, continue sounding throughout operation (Continued) Firefighter I

  21. Safety Precautions During Vertical Ventilation • Always walk on bearing walls, strongest points of roof structure • Ensure ceilings punched through to enhance ventilation Firefighter I

  22. Unsafe Roof — Warning Signs • Melting asphalt • Spongy Roof • Smoke coming from roof • Fire coming from roof Firefighter I

  23. DISCUSSION QUESTION What should you do if you are assigned to ventilate a roof and find warning signs present? Firefighter I

  24. Roof Coverings • Part of roof exposed to weather • Types • Some susceptible to ignition from sparks, burning embers; others not • Some have coating of insulating material Firefighter I

  25. Existing Roof Openings • Sometimes used for vertical ventilation • Rarely in best location/large enough • Usually supplement cut holes (Continued) Firefighter I

  26. Existing Roof Openings • Scuttle hatches • Skylights • Monitors • Ventilating shafts • Penthouse/bulkhead doors Firefighter I

  27. General Ventilation Considerations for Roofs • Square/rectangular opening easier to cut, easier to repair • One large opening better than several small Firefighter I

  28. Flat Roofs • Commonly found on commercial, industrial, apartment buildings • Common on many single-family residences (Continued) Firefighter I

  29. Flat Roofs • May/may not have slight slope for drainage • Frequently penetrated by chimneys, vent pipes, etc. • May be surrounded and/or divided by parapets (Continued) Firefighter I

  30. Flat Roofs • May support water tanks, HVAC equipment, etc. • Structural part • Decking • Construction materials determine equipment necessary to ventilate Firefighter I

  31. Pitched Roofs • Among most common are those elevated in center along ridge with roof deck sloping down to eaves along roof edges (Continued) Firefighter I

  32. Pitched Roofs • Shed roofs — Pitched along one edge with deck sloping down to eaves at opposite edge • Most involve rafters/trusses • Have more pronounced downward slope than flat; may be steep (Continued) Firefighter I

  33. Pitched Roofs • Procedures for opening similar to flat roofs; precautions must be taken to prevent slipping • Some types may require different opening techniques Firefighter I

  34. Arched Roofs • Can span large open areas unsupported by pillars/posts • One type uses bowstring trusses (Continued) Firefighter I

  35. Arched Roofs • Lamella or trussless arched roofs (Continued) Firefighter I

  36. Arched Roofs • Procedures for cutting ventilation openings same as flat/pitched except no ridge to hook roof ladders; curvature of roof prevents roof ladders from lying flat Firefighter I

  37. Precast Concrete Roofs • Can be fabricated off-site • Available in many shapes, sizes, designs • Some use lightweight material (Continued) Firefighter I

  38. Precast Concrete Roofs • Lightweight usually finished with roofing felt and mopping of hot tar • Extremely difficult to break through • Existing openings should be used for ventilation on heavy roofs Firefighter I

  39. Poured-In Place Concrete Roofs • Some lightweight concrete roof decks poured in place over permanent form boards, steel roof decking, paper-backed mesh, or metal rib lath (Continued) Firefighter I

  40. Poured-In Place Concrete Roofs • Relatively easy to penetrate • Some can be penetrated with hammer-head pick or power saw with concrete blade • Heavier roofs require jackhammer/diamond-tipped chain saw Firefighter I

  41. Metal Roofs • Made from several different kinds of metal; constructed in many styles (Continued) Firefighter I

  42. Metal Roofs • Light-gauge steel roof decks can be supported on steel frameworks/laid over existing roof • Light-gauge cold-formed steel sheets used primarily for industrial buildings (Continued) Firefighter I

  43. Metal Roofs • Except when covered with lightweight concrete, seldom covered with roofing material • Metal cutting tools/power saws with metal cutting blades must be used to open (Continued) Firefighter I

  44. Metal Roofs • Often penetrated by roof openings • Older buildings may have roofs made of large pieces of sheet metal laid over skip sheathing Firefighter I

  45. DISCUSSION QUESTION What are some examples of occupancies in your area? How would these occupancies need to be addressed when ventilating the building? Firefighter I

  46. Trench Ventilation (Strip Ventilation) • Used to stop spread of fire in long, narrow structure (Continued) Firefighter I

  47. Trench Ventilation (Strip Ventilation) • Performed by cutting large opening at least 4 feet (1.2 m) wide extending from one exterior wall to opposite exterior wall • Often, large ventilation opening is cut between trench cut and fire Firefighter I

  48. Mechanical Ventilation • Forced ventilation is accomplished using mechanical ventilation • Tools to complete mechanical ventilation: • Fans • Gas Fans • Electric Fans • Blowers

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