Taxpayers Flashcards
Are walls designed to withstand severe lateral loads?
Walls are NOT usually designed to withstand severe lateral loads
Glossary
Most common dimension of Taxpayer
100’ X 100’ Ch 2
Most prevalent type of TP
Built from 1920’s to 1960’s.
Which type of TP allow for cornices to be removed to provide access to cockloft areas?
Older type built turn of century to 1920’s. Heavy fire in the front of the bldg, the supports of these cornices can be weakened and the cornice can fall to the ground unexpectedly. Ch 2
In TP built from 1920-1960’s will removing the cornice or sign provide access to the cockloft?
In most cases in the most prevalent type of TP built from 1920’s-1960’s, removing the cornice or sign in most cases will NOT provide access to the cockloft area
Ch 2
Sprinkler Protection Rules for TP built under 1938 Code vs 1968 Code
1938: Area exceeding 10,000 sq ft;
1968: Area exceeding 7,500 sq ft
2008 Code Group M Mercantile Rules for Sprinkler Protection in TPs;
Full Bldg vs Occupancy within a bldg
Full Bldg: area exceeding 12,000 sq ft OR combined area on all flrs including mezzanines exceeds 24,000 sq ft. Also, storage of merchandise is in high-piled racks or rack storage arrays.
2008 Code Group M Mercantile Rules for Sprinkler Protection in TPs;
Full Bldg vs Occupancy within a bldg
Occupancy within bldg: area exceeding 7,500 sq ft OR area of any size is located 3 stories above grade OR area of any size is located in Hi-Rise Bldg OR area of any size contains an unenclosed stair or escalator connecting two or more floors.
Cockloft heights in TPs
Vary in height from 4” to more than 6’. Ch 3
Most common roof type in TP
Constructed of wood joists covered with either tongue and groove boards or plywood. Roof then covered with combustible waterproofing material called “tarpaper” or “built up roofing” which may be several layers thick.
The open web joist or steel bar joist prevalent in modern TP construction is _
LW parallel chord truss Ch 3
Bowstring truss roofs may only support _% of the load they were originally desgined to hold
40%. Snow loads also add eccentric (off-center) unbalanced, concentrated loads that can overload trusses Ch 3
In older type truss roof bldgs, the trusses may be spaced _ to _’ apart with roof beams installed between the trusses to support the roof coverings
10 or 20’ Ch 3
Wood truss failure vs Steel truss failure
Wood truss roofs fail without warning- roof does not sag or get “spongy.”
Steel “stretches” when losing strength, wood tends to “snap” Ch 3
Bldgs w/bowstring truss roofs must be entered into eCIDS with abbreviation
BWSTRG Ch 3
Fire resistance of Open Web Steel Joists
Open Web Steel joists have NO Fire resistance rating. Fire rating depends upon ceiling finish and finish roofing. Ch 3
Open Web Steel Joists may span _’
Long distances up to 60’. Ch 3
Unprotected open web steel joists are particularly vulnerable to elevated temperatures of a fire and may collapse after only _ minutes
5-10 minutes Ch 3
T/F Stability of masonry walls is very much dependent on the integrity of the roof. Roof acts as a monolithic brace which ties the walls together. Collapse of roof imparts a lateral load, either pushing out or pulling in, on the wall as stresses are formed
True Ch 3
T/F Interior partition walls between stores are usually of wood stud construction, with plaster or sheetrock covering, and are usually firestopped at floor and ceiling by wood sills and plates.
True. Removal of large sections of plaster will weaken bracing. Ch 3
An average 50’ long steel beam, heated uniformly over its length to 970 degrees F will extend in length approx _”;
At 1000 F a 100’ long beam will have extended in length _”
Approx 4”;
9 1/2”
Ch 3
Should hot steel beams or columns be cooled with water?
Do not hesitate to cool these members. However, if the beam has already sagged under the weight of floors or roof, FFs should NOT be allowed in the possible collapse zone even if cooled. Ch 3
Cast iron columns are unpredictable and fail, on average in about _ minutes
30 minutes. Ch 3
Most common type of flooring in TPs
Tongue and groove boards or plywood, supported by wood floor joists. Ch 3
Which type of TP could removing the paneling under the front window display allow for vent and water application
Older type TP. The flooring of 1st fl may not be extended under the raised front window display. Newer TP concrete flrs are prevalent on ground level with no basements or cellars in bldg. Ch 13.
Colors of smoke associated with backdraft
Dense black Dirty brown Yellow brown Gray yellow Ch 4
Can a Backdraft occur anywhere in TP
Yes, although cellars and storage areas are particularly vulnerable. The tighter the bldg or area is to air seepage, the greater the danger. Ch 4
A room or fire area requires only _% of its space to contain the explosive mixture for the entire area to possible explode.
25% Ch 4
Most fires in TP originate _
Rear of 1st floor where utilities, storage, and services are located. Generally, this is the lowest portion of the cockloft Ch 5
Roof cut at TP recommended size
8’ X 8’ Ch 5
When shall a Roof Sector Supervisor be used at a TP fire?
When more than 1 power saw is working on the roof. Could be a Chief or Co Off. Ch 5
When should a Chief be used as a Roof Sector Supervisor
Where roof cutting is critical. Ch 5
Bowstring Truss Roof: Can interior attack occur?
IC may implement interior attack, AFTER a risk assessment for: Current structural stability of bldg Any known life hazard Verification of safe access to fire area Size and location of fire
Ch 5
Bowstring Truss Roof: Roof Ops allowed?
Under NO Circumstances shall any member operate on roof of any bldg involved in a CONTENT or STRUCTURAL fire w/wood, metal, or combo bowstring truss design. Ch 5
Methods to discover if fire entered bowstring truss roof in bldgs with ceilings covering view of roof
Use TIC from below to assess OR make a triangular cut in the sloping hip section in front and/or rear of roof from safety of TL bucket. If fire found in truss space= exterior attack. TL may be used to extinguish Ch 5
Units are reminded of collapse potential in Bowstring Truss Roof construction with particular attention being paid to _
Front and rear walls. Due to hip rafters being pushed in a down and outward fashion when main roof collapses. Ch 5