Building Construction/Roof Ops Flashcards
Rafters run ______ to beams on a lightweight panelized
Parallel
Purlins run _______ to beams and rafters
Perpendicular
How far apart are purlins on lightweight panelized?
8’
What are the dimensions of purlins?
4” x 12”
What are the dimensions of beams on lightweight panelized?
6” x 36”
How far apart are beams on a panelized??
12’ to 40’
If leading roof op as engineer, order to ascend ladder and travel?
- Engineer
- Most experienced FF
- Least experienced FF
- Captain
Smoke condition 4 factors?
Volume, velocity, density, color
What is the difference between an arched rib and an arched truss?
- Arch rib = rafters on top of arch
- Arch truss = rafters on hangers
Does a bowstring roof have truss construction?
No, just bowstring and arch
3 main eras of building construction?
- Pre-33
- 1933-1950
- 1950- present
Pre 33s have _____ roofs and ______ walls
Strong roofs
Weak walls
(Unreinforced masonry)
Signs of a Pre-33 building?
- Brick/Kings-row
- In-line windows
- Inset windows
- Balloon Frame
1933-1950 strengths:
- Strong roof
- Strong walls
- Conventional lumber
1950s and newer have ____ walls but ______ roofs
Strong walls but weak roofs
When would you do an inspection cut on a residential roof?
Lightweight residential, checking for gusset plates
Offensive vs. Defensive strip
Offensive- strip on the involved unit
Defensive- strip behind the fire wall of the involved unit to save the adjacent unit
When to do inspection cuts?
- Flat roofs
- Change of elevation
- Cross a fire wall
- Change of construction direction
- Change of elevation
What are you looking for with an inspection cut?
- Lumber size
- Lumber direction
- Roof material/decking
- Lightweight construction/gussets
- Attic space/attic involvement
Commercial/apartment fire 1st truck ladders?
- Aerial uninvolved to involved
- Ground ladder closer to fire
Commercial/apartment fire 2nd truck ladders?
- Back up aerial ladder
- Emergency bail out ground ladders
- Ground ladders to back-up/reinforce aerials
How often should you traditionally place smoke indicators?
Every 10’
What’s the strong part of a Lamella roof?
Outer perimeter
Concern with Lamella roofs?
Domino effect if roof failure
Use extreme caution if heavy fire conditions
Type 1 construction?
Fire resistive
(Steel coated, concrete)
(Jails, hospitals, schools, high-rise)
Type 2 construction?
Noncombustible
(Uncoated steel/steel frames)
Metal floors/roof with concrete tilt up walls
Type 3 construction
Non-combustible walls/roof, normal contents on the insides
(Most businesses, strip malls)
Type 4 construction?
Heavy Timber
(Churches, factories, cabins)
No void spaces, wood minimum 8” thick
Type 5 construction?
Wood frame
Houses
How are I Beam, bar joist/open web joist roofs constructed?
Large beams perpendicular to chorded trusses either with wood or metal bars.
Lightweight and can fail easy
Don’t always have beams if small building
Conventional flat construction?
Large beams with large rafters running perpendicular, usually 2 x 12” minimum
Arched roof operations?
- Ladder uninvolved to involved
- Try to exit onto Jack Bay
- Inspection cut where Jack Bay meets the arches to determine what kind of arched roof
- Strong roof so ventilate over the fire
- Consider 1 bay back if bowstring, and use extreme caution
- Try to work off of an arch
- Strip along the arch if needed
- Consider pull back style cut if it has 1 x 6” sheeting, use caution to not fall thru
Is a strip mall typically lightweight or conventional?
Lightweight
Concerns of strip malls
Mansards, facades, parapets, common attics, lightweight construction
Considerations for aerial ladder on a strip mall?
- Uninvolved to involved
- If defensive, where’s the most building to save?
- Ladder B,C, or D sides to avoid mansards and parapets
- Don’t ladder over involved unit if lightweight
