Ch 9-10 Flashcards
(50 cards)
Character characteristics of male construction include
Exterior walls are solid masonry, usually brick or stone
Columns and beams are heavy timber with cast iron connectors
Floors and roofs are thick grooved, splined, or laminated planks
Fire cut girders
Scuppers in the walls
No concealed spaces
Large numbers of windows
Automatic sprinkler system with a water flow alarm
Special hazards are located in detached buildings
Heavy timber construction, specifically post World War I, are considered to be characteristically:
So-called slow burning, but only while interior offensive operations are happening.
When the fire gets into the structure, it becomes long burning.
A defensive fire in a heavy timber building is a massive fire. This is due to:
A tremendous amount of radiant heat
Potentially large collapses zones
Likely exposures and fire brand carriers
May have ventilation problems
The only fire protection measure that can reasonably be expected to prevent a disaster in a heavy timber building is
Full fire sprinkler protection that is adequately maintained
Minimum dimensions for heavy timber structural members
Wood columns, at least 6x8”
Wood beams and girders, at least 4x6”
Laminated arches and timber trusses at least 6x8”
Cross laminated timber or CLT is a new product, popular in Europe.
Typically incorporates 2x? material laminated, glued under pressure, and laid perpendicular.
The number of layers is typically 3 to 7 in odd numbers.
CLT panels can range in size from:
Range from 2-10’ wide and as much as 60’ long
CLT is usually used for columns, floors, and wall members
New categories for heavy timber construction are
Type IV-A - max of 18 stories and covered with gypsum board
Type IV-B - max of 12 stories with limited wood exposure
Type IV-C - max of non-stories with all Wood exposed, 2-hour fire resistance test
Mass plywood panels or
MPP are:
Large flower panels, up to 12 foot wide by 48 foot long and 24 thick
Water curtains between a heavy timber building and exposures should
Not be used. Water curtains provide little to no protection. You should wet exposures
Ordinary construction describes almost infinite variety of buildings. Until recently, the chief characteristic was ??
Exterior walls made of masonry.
The IBC was changed to allow the use of fire retardant with exterior walls.
An ordinary construction, fire limits are provision, stating that:
A structure could not be built unless the outer walls were constructed of masonry to limit fire extinction
2 common examples of a type three ordinary construction building are:
Main Street USA
Specifically, 1- story strip malls with lightweight wood roof trusses and concrete walls.
Traditional or legacy ordinary construction buildings consist of mason, bearing walls and wood joists spanning wall wall. The joist are typically:
Parallel to the street frontage or the smallest building dimension.
In most cases, there’s a flat roof with a cockloft or void space
The bearing walls are typically on the sides, non-bearing walls are front and back.
Most ordinary construction buildings have a practical width limit of about
25 feet.
More than that requires a girder, beam and column.
An inherent hazard in ordinary construction is the existence of:
Void spaces. The void base between the top floor and the roof is the cockloft.
Voice spaces may hide CO or hidden fires.
There is a limit to the height of masonry type three buildings due to the thickness of the walls. Height limits include:
Usually 3 to 4 stories, may be as high as 7 stories.
4+ story buildings usually have a class 1 or a class 3 standpipe
Tallest is 15 stories, the Monadnock building in Chicago.
A few of the lesser known masonry, construction terms:
Ashlar masonry– stone cut in rectangular units
Coping – mason recap on top of the wall
Pargjng or pargetting- covering a masonry wall with a thin coat of concrete
In some codes in ordinary construction, concrete topping was required. This is:
Concrete over first floor wood floors for fire resistance, or to provide a sanitary floor.
This is additional dead weight and may conceal heat below.
In ordinary construction, an exterior collapse will usually cause an interior collapse. Conversely, fire damaged, steel beams for interior claps may cause the walls to collapse.
Other problems associated with type three reconstruction include
Masonry wall problems
Stability of interior columns, girders, and beams
Void concealed spaces
Masonry walls as a barrier to fire extension
Indications of building failure or impending collapse include
Smoke or water flowing through the walls
Soft floors
Partial collapse
Walls out of plumb
Amount of time on scene
A general rule of ordinary construction is that these buildings are built without any thought to what would happen in the event of a fire. This means:
These buildings are non-fire resistive, they have no designed resistance to collapse in a fire.
A masonry wire truss is:
A wire truss embedded in the motor in specific courses, discarding the need for a header course in a masonry wall.
This makes it difficult to tell a veneer wall from a bearing wall
The use of cast-iron and ordinary construction was generally used for:
Columns, arches, or lintels at the street floor level to carry the masonry above openings
