Vertical vent Flashcards
WHEN TO PERFORM VERTICAL VENTILATION
- Single story residential structures with backdraft conditions
- Lower floor of a residential structure with backdraft conditions
- Attics including knee wall spaces
- Top floor of a multi-story buildings
- Large single-story commercial buildings
When fire is in both the knee wall space and the attic space, the __ space should be
vented first, followed by the venting of the __ space lower on the roof.
attic, knee wall
Balloon frame. Truck crews should be in place on the roof and be prepared to perform coordinatedvertical ventilation in the event that extension to the attic or top floor occurs. The roof___ be opened until it has been visually confirmed that fire has extended to the
attic or the top floor living spaces of the structure.
should not
When fighting fires in balloon frame structures, It is especially important to have ___ready before holes are opened in the walls, ceilings, or roof.
hoselines
For the purpose of ventilation operations, roof construction types are placed in two broad
categories: ___
lightweight and conventional
Conventional: As a general rule, a conventionally constructed roof structure will sustain fire involvement for ___ before failure of the roof should be expected.
20 minutes
With conventional construction, roof rafters are made from solid pieces of dimensional
lumber typically spaced___ inches apart.
twelve to sixteen
When conducting ventilation operations on conventionally constructed roofs, the heat hole
should be cut ____ when conditions permit.
directly over the fire
The sheathing used on conventionally framed roofs often consists of __ tongue and
groove board’s nailed perpendicular to the rafters.
1” x 6”
The method that is utilized is dependent on the direction of the rafter and will be described as ___
working with and working against the construction
Begin an inspection hole by plunging the tip of the saw into the roof
material at the furthest point from the egress ladder. Make a cut that is at a ___ to the ridge line or the edge of the roof. Continue the cut with until a rafter is felt, roll over the rafter, mark the location, and then continue the cut until a cut of about ___
45-degree angle,18 inches is made
A standard cutting sequence for constructing a heat hole when working against
construction is:____
Head – Far – Bottom – Near
A ventilation opening on a flat roof should always begin with an___
inspection hole
The coffin cut uses a sequence of cuts that forms the shape of
the numbers ___
7, 9 and 8
The coffin cut will create a heat hole that is up to ___
feet in size and can be easily expanded.
4 feet by 8
There are two instances when it may be desirable to use this cutting procedure. The first
is on a conventionally framed flat roof with ____ sheathing and roof rafters that
are spaced ____.
1 inch x 6 inch, 12 to 24 inches on center
A coffin cut should not be attempted on a roof with___ because the
panels of roofing material will be very difficult to remove from the rafters without further
dicing
plywood sheathing
The only time a heat hole is not placed before a trench cut is if the fire has ___.
significantly self-vented
Trench cuts can be used to cut off a rapidly extending cockloft fire at a pinch point. The
pinch point or “____” could be defined as an area where a building narrows sufficiently
to perform a successful operation before the fire can extend past that point.
throat
A trench cut must be placed across the width of a flat roof to be effective, leaving only a
___ area of uncut roofing at each exterior wall for an egress path if necessary
four-foot
For a gable roof, the trench should extend about __ of the distance to the eves on
both sides of the ridge.
two-thirds
Trench cutting is a time-consuming process that must be considered and ___ to
be successful.
started early
Most bulkhead doors are outward swinging, lightly to moderately secured, and can be
forced by a single member. The basic procedure is “___”.
Gap-Set-Force
While forcing a scuttle is usually quick and easy some may require cutting. It is faster
and easier to ___ then to cut the roof around it. This is also
significantly less damaging during minor fires
cut the top of the scuttle out
Opening skylights is a rapid and effective way to provide ___
natural ventilation
Glass skylights Break a single pane of glass and wait for ___
ten seconds
Most glass skylights use___
wired glass
Skylights are common on ordinary apartment buildings because these structures
frequently predated modern lighting methods. As interior lighting of the hallways and
stairs improved, many skylights were covered over to improve security and energy
efficiency. These covered skylights are normally ____ or larger raised
areas on the roof that are in-line with the central hallway or a stairwell.
four feet by eight feet
