Ch. 5 Collapse dangers of parapet walls Flashcards
The most dangerous area outside a burning structure is the sidewalk directly in front of the bldg. and is even more deadly if the bldg. has what type of wall?
A parapet wall
The most dangerous parapet is the one constructed as the front wall of a one story structure above several large what?
Several large display windows.
This type of parapet is supported on top of a steel I-beam acting as a lintel. It is supported by narrow masonry or cast iron columns.
From the list below choose the incorrect design defect in the construction of a parapet wall:
- Free standing wall
- Steel lintel
- Steel reinforcement rods embedded in a parapet wall
- Coping stones of a parapet wall
- Finished brick of a parapet wall
Finished brick is incorrect
UNFINISHED BRICK OF A PARAPET WALL
In what stage of the fire does the parapet wall usually collapse?
During the overhauling stage of the fire.
The coping stone of a parapet wall can be made out of terra-cotta, cement or slate which can weigh from____________ pounds?
10-50 lbs.
When a serious fire takes control of a large underside of a bowstring truss roof that has sloping hip rafters extending from end trusses to the front & rear parapet walls. The IC should anticipate a roof collapse followed by what?
An explosive front & rear parapet wall collapse
If the top of an aerial device (aerial, TL, Snorkel) is obscured by smoke or darkness, and it is raised near the top of a parapet and repositioning is required we shall assume what prior to repositioning it?
That the aerial device is resting on the wall and should be raised 1st prior to retracting it.
