FVCC Fire Rescue

VentilationPart C

CHARACTERISTICS OF ROOF TYPES•Flat

▫ Commonly found on commercial, industrial and apartment buildings

▫ May have a slight slope to it▫ Roof may be surrounded or divided by parapets▫ May support:

Water tanks Air conditioning units Equipment Antennas Other obstructions

▫ Structural part similar to floor construction

PRECAUTIONS WHEN VENTILATING•Flat

▫Use roof ladder.▫Look for hot spots or sagging of the roof

area PRIOR to walking on surface and continually during ventilation.

▫Always sound roof PRIOR to walking on surface and continually during ventilation.

PRECAUTIONS WHEN VENTILATING

▫Look for roof additions or changes, such as overhangs, inverted flat roofs, security measures, parapet walls.

▫Look for obstacles and excess weights on roof, such as HVAC systems, skylights, vent pipes, other openings.

▫Provide two means of escape from the roof remote from each other.

PROCEDURES•Vertical

▫Flat roof Determine location of opening

Location of seat of fire Direction of wind Existing exposures Extent of fire Obstructions

PROCEDURES Locate supports by sounding with

an axe. Mark the location for opening by

scratching a line on the roof with the pick head.

Remove the built up material or metal by cutting the materials and using the pick head to pull the materials out of the way.

Cut the wood decking diagonally alongside the joist towards the hole.

Pry up the roof boards with the pick end of the axe.

After opening the roof, push the blunt end of a pike pole or plaster hook through the opening to penetrate the ceiling below.

CHARACTERISTICS OF ROOF TYPES•Shed

▫Similar to flat except slopes from front to back

▫Slope may be gradual or steep

PRECAUTIONS WHEN VENTILATING• Shed

▫ Use roof ladder▫ Look for hot spots or sagging of the roof area PRIOR

to walking on surface and continually during ventilation.

▫ Always sound roof PRIOR to walking on surface and continually during ventilation.

▫ Look for roof additions or changes such as overhangs, inverted flat roofs, security measures, parapet walls.

▫ Look for obstacles and excess weights on roof, other openings.

▫ Provide two means of escape from the roof remote from each other.

CHARACTERISTICS OF ROOF TYPES•Pitched

▫Elevated in the center▫Construction

Rafters Run from ridge to top plate Made of wood, metal or combination

PRECAUTIONS WHEN VENTILATING• Pitched

▫ Use roof ladders▫ More profound incline; take extra precautions against

slipping▫ Look for hot spots or sagging of the roof area PRIOR to

walking on surface and continually during ventilation▫ Look for roof additions or changes such as overhangs,

inverted flat roofs, security measures, parapet walls▫ Look for obstacles and excess weights on roof, such as

HVAC systems, skylights, vent pipes, other openings.▫ Provide two means of escape from the roof remote

from each other

PROCEDURES•Pitched roof

▫ Determine location of opening, usually the highest point

▫ Place a roof ladder on the roof so that personnel working off it will be upwind from the hole.

▫ Locate supports by sounding with an axe.▫ Mark the location for the opening by scratching a

line on the roof with the pick head▫ Remove the shingles or roofing sufficiently to

permit the initial cut▫ Cut the sheathing along side a rafter, the distance

required for the opening.

PROCEDURES▫Opposite side is then cut in a like manner.▫Remove sheathing boards with the pick of

the axe▫After opening the roof, push the blunt end

of a pike pole or plaster hood through the opening to penetrate the ceiling below

CHARACTERISTICS OF ROOF TYPES

▫Sheathing▫Roofing materials▫Shingles

Wood Metal Asbestos Composition Tile Slate

▫Pitch of roof may be gradual or steep

INTEGRITY OF A ROOF SYSTEM•Construction

▫Materials Wood Steel

▫Type of roof support Rafters Truss

Commercial Structure Fire 11/11/04, Glenview, IL, US

INTEGRITY OF A ROOF SYSTEM•Visual observation/warning signs

▫“Spongy” roof▫Melting asphalt▫Smoke coming from roof▫Fire coming from roof▫Excess weight (ex. HVAC)

•Elapsed time of fire▫The longer the fire, the less the roof

integrity.

Ventilation Considerations•High rise structures:•Stack effect: fire/smoke spread rapidly via

stairways, elevator shafts, pipe shafts, air handling systems, and other vertical openings.

•Smoke & other fire gases will travel through a high building until their temperatures come to equilibrium with ambient air. This is the floor you will find the maximum amount of smoke.

Ventilation ConsiderationsVentilation Considerations• High rise structures: (cont.)High rise structures: (cont.)• Before doors leading to the involved Before doors leading to the involved

fire floors are opened, the door roof fire floors are opened, the door roof must be blocked opened or removed.must be blocked opened or removed.

• Ventilation in high rise buildings should Ventilation in high rise buildings should be considered during pre-incident be considered during pre-incident planning.planning.

• If the building has a complicated HVAC If the building has a complicated HVAC system, in order to control ventilation system, in order to control ventilation you should call a building engineer. you should call a building engineer.

Considerations involved in Ventilation

Parapet

1. Age of Building (1921)2. Over Bow String Truss3. head wires4. Placement of aerial (only waythis roof structure should be ventilated)

Bow string truss: can be difficult to ventilate Because lower chord of the truss may be covered With a ceiling to form an enclosed roof space.This space is called a cockloft

PRECAUTIONS WHEN VENTILATING•Arched

▫Be conscious of danger of sudden and total collapse.

▫Roof ladders useless, recommend aerial devices.

▫Be aware of concealed voids, such as cocklofts and attic spaces covered by ceilings.

FLAT ROOF CONSTRUCTIONVS 10-10

ParapetSheathing

Felt

Slag or Gravel

Flat (Hung) Ceiling

Bar Joist Parapet

Metal Deck

False (Hung) Ceiling

Flat roof most often found on commercial, industrial, and apartment buildings.

PITCHED ROOF CONSTRUCTIONVS 10-11

Ceiling Joist

Rafter

Wall Plate Siding

Yes, this is a residence!!!So, how do you vent this person’s home? Tin roof should be sliced open with tin snips & peeled back.

Extra Bits of Important Test Stuff

Balloon Frame? Basement Fire? Attic Fire?

What might be the last resort in ventilating a structure to reduce Vertical extension during a basement fire?

First choice in ventilating a basement fire?

What is horizontal extension? Name some methods?

Know your roof types!Know your roof materials!

JOURNAL BUILDING FIRE TUSCOLA, ILLINOIS

Less than 15 minutes after the building`s evacuation, the roof collapsed, issuing a ball of fire 100 feet in the air. Another four minutes passed, and the entire front wall collapsed into the street. Then the upper portion of the side walls of the fire building collapsed onto the exposures. This sent another fireball into the air, enveloping a firefighter operating at the tip of the ladder pipe. Fortunately, he was wearing full protective clothing (including SCBA) and was not injured.

Photo 7. With positive tip load improvements come some operational impediments. Note the deployment of the outriggers on the heavy-duty aerial

ladder in this common suburban/urban setting. The street is completely blocked off.

This multiple-dwelling stucture's very irregularly shaped roof could prove hazardous during nighttime or smoky conditions. The skylight over the main stairwell has apparently been tarred over. At the rear behind the chimney is a scuttle hatch over the rear stairwell

HomeworkMatch types of ventilation to their descriptions. Write the

correct letters on the blanks.1. Process of placing a smoke ejector in a door or window blowing

outward to pull smoke, heat, and gases from a structure and eject them to the exterior

2. Process of venting heat, smoke, and gases, usually through created or existing roof openings above the seat of the fire

3. Process of directing a water stream through a door or window to draw heat, smoke, and gases from the structure

4. Process of trying to stop the spread of fire by cutting a large roof hole — at least 4 feet wide — that extends from one exterior wall to the opposite exterior wall slightly ahead of the advancing fire; particularly useful in long, narrow structures

5. Process of venting heat, smoke, and gases through existing wall openings such as windows and doors

6. Process of placing a fan outside a structure and blowing air into the structure in which an opposite door or window has been opened to allow smoke and gases to escape

a. Vertical b. Horizontal c. Trench (strip) d. Forced pressure e. Hydraulic

Homework• Identify signs of potential backdraft. Mark an “A”

on the blank before each sign of backdraft potential. Mark a “B” before each sign that does not relate to backdraft.

7. Smoke-stained windows8. Dense white smoke billowing from lower levels9. Broken windows10. Smoke puffing at intervals from the building11. Pressurized smoke coming from small cracks12. Deep orange/blue flames shooting from roof

HomeworkSelect true or false for the statements about ventilation decisions. Write an “A” in

the blank for each true statement and “B” in the blank before each false statement.

13. Ventilation must be started before the requirements for a plan of attack are considered.

14. The first ventilation consideration is the safety of firefighters and occupants.

15. Depending on fire conditions, ventilation may need to be performed before rescue operations begin.

16. Before ventilating, the firefighter must consider the insured value of the materials and contents within the building.

17. The need to ventilate is based on heat, smoke, and gas conditions within the structure, and on personnel resources available.

HomeworkSelect true or false for the statements about ventilation decisions. Write an “A” in

the blank for each true statement and “B” in the blank before each false statement.

18. A firefighter can make some ventilation decisions based on visible smoke conditions.

19. Building type and design are the initial factors to consider in determining whether to use horizontal or vertical ventilation.

20. The extent to which a building is connected to adjoining structures has a bearing on the decision to ventilate.

21. Pre-incident planning should include tactics and strategy for ventilating residential buildings.

22. Basements and windowless buildings generally require hydraulic ventilation for the removal of smoke.

Homework• Select from a list building factors that aid the

firefighter in determining whether to use vertical or horizontal ventilation. Write an “A” on the blank before each factor that helps to determine whether to ventilate a structure and an “B” if not.

23. Age of structure24. Building type and design25. Number and size of wall openings26. Number of occupants27. Number of stories28. Number of staircases, shafts, dumbwaiters, ducts, roof

openings29. Accessibility to water source30. Availability of exterior fire escapes31. Exposure involvement

Homework• Select from a list ways in which vertical fire extension

occurs. Write an “A” on the blank before each way in which vertical fire extension occurs and a “B” if it does not.

32. Through stairwells, elevators, and shafts by direct flame contact or by convected air currents

33. Through hallways and passageways by radiation34. Through partitions and walls and upward between the walls

by flame contact and convected air currents35. Through windows or other outside openings where flame

extends to other exterior openings and enters upper floors36. Through interior doorways and archways37. Through ceilings and floors by conduction of heat through

beams, pipes, or other objects that extend from floor to floor

Homework• Mark “A” for true and “B” for false statements about safety

precautions that should be observed when performing vertical ventilation.

38. Start power tools on the ground to ensure operation and keep them running while hoisting or carrying them to the roof.

39. Work with the wind at your back or side to provide protection while cutting the roof opening.

40. Note the existence of obstructions or excess weight on the roof.

41. Make sure that the angle of the cut is toward the body.

42. Provide a secondary means of escape for crews on the roof.

Homework• Mark “A” for true and “B” for false statements about safety

precautions that should be observed when performing vertical ventilation.

43. Extend ladders no more than four rungs above the roof line and secure the ladder.

44. When using elevating platforms, the floor of the platform should be slightly below roof level.

45. Use lifelines, roof ladders, or other means to protect personnel from sliding and falling off the roof.

46. Work in groups of at least two, with at least one more person than absolutely necessary to get the job done.

47. Ensure that all personnel on the roof are wearing full personal protective equipment including SCBA.

TYPES OF FORCED VENTILATIONVS 10-16

a. Horizontal Mechanical b. Hydraulic c. Positive Pressure

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Homework

a. Butterfly b. Flat c. Lantern d. Mansard

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Homework

a. Arch b. Gable c. Gambrel d. Hip e. Shed

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EXISTING ROOF OPENINGSVS 10-9

a. Monitor b. Ventilator c. Scuttle Hatch d. Stairway Door With Skylight

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Homework

a. Bow String Truss b. Flat roof c. Pitched Roof d. Trussless

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