G6 - Concrete Stairs Flashcards
What is a closed stairwell?
Enclosed on both sides of the stairway. Handrail is attached on the wall on one or both sides.
Describe a narrow U stairs:
Narrow U Stairs have two flights of stairs running in opposite directions with a landing at the mid-way point. Compact.
Describe wide U Stairs
Have three flights separated by two landings. Stairway has an open center that allows light to penetrate to flights below.
Describe long L stairs:
Long L stairs consist of long straight flight, with a short flight of 2 or 3 treads at the top or bottom at a right angle to the long stairs.
Landing or winder used at change of directions.
Describe Wide L stairs:
Consist of two straight flights at right angles to each other, with a landing or winders at the change of directions.
Describe double L stairs:
Consist of a straight flight, with 2 or 3 threads at right angles to the main stairs at both the top and bottom. A landing or winders are used at the change of direction.
What is the purpose of a stair landing?
Give access from one floor level to another with intermediate landing.
Finish surface of a concrete step should be:
Slip resistant and the surface should slope away from the building to allow drainage.
Alternative to cast-in-place stairs:
Pre-cast stairs
Pre-cast stairs placed over:
Excavated grade or attached to wood, metal or concrete stringers.
Which forms are used for Pre-cast stairs?
Steel, as it is easy to clean and gives a smooth exterior finish to the stairs.
Reinforcing in concrete stairs is placed where?
From the soffit side.
Concrete is used in commercial construction because of the:
Durability and resistance to fire.
Concrete stairs are supported on previously placed concrete and structural components and structural components are attached with:
Steel dowels.
To simplify construction of pre-cast concrete stairs:
Rebar dowels are sometimes threaded into the threaded inserts cast into walls.
To make nosing resistant to damage, a nosing insert is used:
Nosing consists of metal edge that is placed in the concrete as it is being finished.
Purpose of nosing:
To provide a space for the toe or heel when walking up or down the stairs.
Amount - measurement of nosing is:
25 to 30 mm
Raked nosing:
Easiest nosing to form - slope the riser form to create a tread depth greater than the tread run
Angled nosing on on underside is not allowed to be less than:
60 degrees to the horizontal.
Nosing:
Projection of the tread or floor beyond the face of the riser base.
Nosing line:
Imaginary line drawn along the top edge of the nosing.
Tread depth:
Sum of the run PLUS nosing.
Stair soffit slab:
Supports the steps
Stair soffit:
Underside of the stair soffit slab.
Flight of stairs:
Series of steps between landings.
Headroom:
Vertical distance from the nosing line to the underside of the floor or beam above.
Opening in the floor for the stairs is called:
Stairwell
What is the difference between a long L stair and a Wide L stair?
Long L has a long flight and a short flight connected by landing or winders
A wide L has 2 similar length flights at right angles to each other
What is the difference between an open stairwell and a closed stairwell?
Closed stairwells are enclosed on both sides
Open stairwells have one or both sides open to a room or hallway
Why are landings used between flights of stairs?
Landings break long lengths of flights and allow stairs to change directions.
What is a stair soffit slab?
Structural concrete slab that support the steps.
Wide U
L shaped with landing
L shaped with landing
