Ventilation Basics in Building Construction

1. Refresher - Ventilation Basics Brantley County Fire Departments Monthly Training Conducted by the Atkinson Volunteer Fire Department July 2008

2. Welcome • Introductions • Housekeeping Atkinson Volunteer Fire Department

3. Terminal Objective The student will demonstrate the principles of ventilation, a basic understanding of building construction, the safety precautions to be taken when ventilating a structure, and how to use the various types of ventilation through classroom participation and discussion. Atkinson Volunteer Fire Department

4. Enabling Objectives • Discuss principles of ventilation • Identify the 5 classifications of building construction • Identify several different roofing styles • Identify safety precautions that should be taken when undertaking ventilation operations Atkinson Volunteer Fire Department

5. Enabling Objectives • Discuss different methods of conducting ventilation • Discuss techniques for ventilating different structure types and roof styles Atkinson Volunteer Fire Department

6. Principles of Ventilation

7. What is Ventilation? The planned, methodical, and systematic removal of pressure, heat, smoke, toxic gases, and flame from an area through predetermined paths and the replacement of these products with cooler fresh air Principles of Ventilation

8. How does it work? • Heat and smoke rise • Path of least resistance • Smoke moves horizontally and vertically – mushrooming Principles of Ventilation

9. Why do we ventilate? • Removal of smoke, heat, and fire gases • Improve visibility • Reduce potential harm to victims • Reduce stress on firefighters • Assist with fire control and extinguishment Principles of Ventilation

10. Advantages • Increased visibility • See the victim • Find the seat of the fire • Increased effectiveness of fire attack • Reduced possibility of flashover or backdraft • Aids in property conservation • Small amount of ventilation damage results in larger reduction in overall fire damage Principles of Ventilation

11. Results Depend On • Size and type of occupancy • Extent and location of fire • Whether fire is free-burning or smoldering Principles of Ventilation

12. Ventilation Concerns • Fire travel by convection – greatest firefighting problem • May cause exposure fires and additional fires in fire structure • Improper ventilation may increase fire spread Principles of Ventilation

13. General Rule To open the fire building so that all accumulations of heat and combustion products leave by means of natural convection Principles of Ventilation

14. Building Construction

15. 5 Classifications • Type I – Fire Resistive • Type II – Noncombustible • Type III – Ordinary • Type IV – Heavy Timber • Type V – Wood Frame Building Construction

16. Type I – Fire Resistive • Made of noncombustible materials • Structural elements subject to damage by heat must be protected by noncombustible coverings • 2 to 4 hour fire resistance rating • Shopping malls, office buildings, etc… Building Construction

17. Type II - Noncombustible • Made of noncombustible materials • Structural elements subject to damage by heat generally not protected by noncombustible coverings • 0 to 2 hour fire resistance rating • Warehouses, repair shops, etc… Building Construction

18. Type III - Ordinary • Exterior walls made of noncombustible materials • Interior walls generally made of wood • 0 to 1 hour fire resistance rating • “Main Street USA” Building Construction

19. Type IV - Heavy Timber • Exterior walls made of noncombustible materials • Interior structural members made of heavy timbers • Mills Building Construction

20. Type V – Wood Frame • Made of combustible materials • May have up to 1 hour fire resistance rating • Residential structures • Most Type V structures built today use lightweight construction methods Building Construction

21. Hipped Gable Gambrel Saltbox Mansard Flat Shed Arched Roof Styles Building Construction

22. Hipped Roof - Simple • All four sloping sides meet at a ridge across the top. Front slope is usually broader than the side sections Building Construction

23. Hipped Roof - Pyramidal • All four sloping sides come to a point at the top of the roof Building Construction

24. Gable • Two flat slopes that are joined together to form a ridge, thus creating a peak or triangle on the wall of the front façade Building Construction

25. Gambrel • Each side has two slopes; a steeper lower slope and a flatter upper one; associated with barns Building Construction

26. Flat • Contains no slope. May or may not have eaves Building Construction

27. Saltbox • A gabled roof with asymmetrical sides. It is said to resemble an eighteenth century salt box Building Construction

28. Mansard • A roof forming a double slope, two slopes on each of the four sides. The lower slope being steeper than the other Building Construction

29. Shed • One high pitched plane covering the entire structure. Often used for additions and porches Building Construction

30. Arched • Roof that curves from wall to wall, may go completely from ground to ground. Used in aircraft hangers, bowling alleys, and older grocery stores Building Construction

31. Roof Construction • Rafter and beam • Lightweight wooden truss • Steel truss Building Construction

32. Lightweight Wood Truss • Engineered with lumber sized smaller than traditional dimensional lumber • Accounts for over 60% of all new construction • Very short life expectancy when exposed to fire Building Construction

33. Lightweight Wood Truss • Held together with gusset plates instead of nails Building Construction

34. Safety Precautions

35. Safety Precautions • Always wear full PPE, to include SCBA • Always vent at highest point possible • Have hoselines in place to make interior attack • Work with wind at back or side • Never flow water into vent hole with personnel inside building • Check roof stability before starting operations Safety Precautions

36. Safety Precautions • Restrict number of personnel to minimum needed to accomplish task • Work from roof ladder when cutting hole • Watch out for overhead power lines • Have secondary escape routes in place • Check equipment before going on roof • Do not cut main structural supports Safety Precautions

37. Safety Precautions • Watch out for unsafe or deteriorating conditions • Note and avoid any existing dead loads or obstructions • Maintain communications • Remove crew from roof when vent operations concluded Safety Precautions

38. Lightweight Construction • Notify IC when lightweight truss construction found • Avoid working around areas with roof mounted equipment • Always expect imminent collapse when lightweight truss construction is being impinged by fire • Work off of aerial ladders where possible Safety Precautions

39. Backdraft Sudden violent reignition of a closed compartment fire when a new source of oxygen is introduced Safety Precautions

40. Backdraft Signs • Smoke visible, but no flames • Yellowish colored smoke • Windows darkened over • Smoke puffing from openings (breathing building) • Smoke under pressure Safety Precautions

41. Rollover Smoke and fire gases advancing along a ceiling until stopped by walls Safety Precautions

42. Flashover • The sudden rapid ignition of all contents of a room or area • Seconds to escape Safety Precautions

43. Flashover Signs • Rollover progressing close to floor • Large amounts of flame and heat with little smoke • Tunnel Effect Safety Precautions

44. What Can Go Wrong • Fatality • September 14, 2002 • A firefighter died after falling through roof while observing another firefighter conducting ventilation operations. The deceased firefighter was not wearing SCBA. • Source – NIOSH Fatality Assessment and Control Evaluation Investigation Report 2002-40 Safety Precautions

45. What Can Go Wrong • Near Miss • March 1, 2003 • Firefighters were conducting search operations in low attic when one firefighter felt a jerk to his helmet. The firefighter immediately dropped to the floor and the interior crew exited the building. Observation of struck firefighter’s helmet revealed where chainsaw from vent operations struck him. • Source – National Firefighter Near Miss Reporting System Report 05-0000339 Safety Precautions

46. What Can Go Wrong • Near Miss • January 13, 2007 • Firefighters were conducting trench ventilation operations on a church made from lightweight truss construction. Personnel were operating from an aerial ladder when 40 feet of roof collapsed, sending a 30 foot fireball into the sky. • Source – National Firefighter Near Miss Reporting System Report 07-0000726 Safety Precautions

47. What Can Go Wrong • Near Miss • December 19, 2005 • Firefighters were conducting vent operations on an ice covered roof and were having trouble getting back to their ladders. Personnel from a neighboring department were able to move an aerial ladder to the crew to aid in exiting roof. • Source – National Firefighter Near Miss Reporting System Report 07-0000854 Safety Precautions

48. What Can Go Wrong • Near Miss • December 7, 2007 • Firefighters were conducting training on ventilation operations when the chain and chain guide came off chainsaw. • Source – National Firefighter Near Miss Reporting System Report 07-0001157 Safety Precautions

49. Ventilation Methods

50. Direction of Travel • Horizontal • Vertical Ventilation Methods