Ch. 13 Stairway collapse Flashcards
There are 3 basic type of stairways that members of the fire dept. may encounter. The preferred stairway used in modern construction is the?
U-shaped stairway- reduces the amount of floor area needed for the stair enclosure, and is often constructed with a steel frame.
A straight run stair provides uninterrupted passage between 2 floors. What type of straight run stairway would you commonly find in a Loft bldg.?
“Continuous” straight run stair-extends from the 1st floor to the top floor in one continuous flight of stairs.
What types of stairs would you usually find in a Private dwelling?
L-shaped stairs-2 section stair that changes direction at a 90 degree angle. It has one section longer than the other
A straight run stair provides uninterrupted passage between 2 floors. What type of straight run stair is used in Multi story bldg.? (used in brownstones)
“Stacked” straight run stairs-A person walks up 1 flight of steps to the floor above, reverses direction, then walks along the hallway to the foot of the stairs leading above, and keeps repeating the process.
Stairways in most multi story bldg.’s today are fire protected; the underside of the wooden stairs has a fire retarded soffit-usually made of wire lath and plaster. the balusters supporting the stair railing are usually required to be non-combustible. The stringboards covering the ends of the steps are usually required to be non-combustible. What does DUNN say about the stairway in a wooden interior bldg. in regards to the initial fire attack?
“The stairway is the safest area in the wooden interior bldg. and logically the best avenue for the initial fire attack.”
Straight run and L-shaped stairs are dependent on the floors for support, but will not collapse with them?
True or false
False
Straight run and L-shaped stairs are dependent on the floors for support and will collapse with them
Steel framed U-return stairs have different collapse dangers than wooden stairs. The steel frame risers, stringboards and the railings rarely collapse. The most serious injuries to members on these stairs occur when what collapses?
The intermediate stair landing
The intermediate landing is the most serious danger of a u-return stair. However the failure of a stone stair tread or step, is the most frequent cause of collapse. When climbing a steel framed, u-return stair with stone treads the member should not allow the stone tread to support his weight by placing the middle of his foot on the stone tread where?
A member should place the MIDDLE of his foot on the stone tread, directly over the riser.
The intermediate landing is the most serious danger of a u-return stair. A member should avoid stepping on the intermediate landing, IF POSSIBLE.
How can we avoid stepping on the intermediate landing?
A member should hold onto the banister and step from a spot above the riser of the lower stair section’s topmost tread to a spot above the riser of the upper section’s lowest tread, and then swing around.
FF’s place more stress on stone or marble stair treads while ___________ than ___________, thereby creating a larger potential for collapse.
Fill in the blanks
Descending than ascending.
When placing a ladder over a fire damaged stairway members must insure that the ladder is supported by what?
The ladder is supported by the floor below and the floor above, not the stairway itself.
When using an interior stair for a hose line attack, avoid bunching up on the stairs. as soon as conditions permit where should the members move off the stairway to?
The fire floor
