Stair Terminology

Question 1

Define rise

Answer 1

The vertical measurement (hight) from finished floor to finished floor

Question 2

Define unit rise

Answer 2

The vertical rise measurement of each step measured from top of tread to top of tread.

Rise
————
# of steps

Question 3

What are unit rise limitations

Answer 3

Max. Min.
Private- 200. 125.

Public- 180. 125.

Question 4

What are the unit run limitations

Answer 4

Max. Min.

Private- max 355. Min255.

Public- max no limit. Min 280

Question 5

Define headroom

Answer 5

The clear distance measured vertically from line of flight to any obstruction above ( NBC refers as hight over stairs)

Min. 1950mm (residential)

Min. 2050mm (public)

Question 6

Define line of flight

Answer 6

An imaginary sloping line that intersects the outer edges of all the nosings

Question 7

Define DTLF

Answer 7

The vertical measurement calculated by adding the required headroom and the total thickness of the upper floor including ceiling finish

Question 8

Define a landing

Answer 8

The horizontal measurement from obstruction to obstruction, of the level floor at the top or bottom of a flight of stairs or may be at a intermediate level area where two flights of stairs change direction

Question 9

What are the limitations of a landing

Answer 9

Should be as wide and as long as the width of the stair:

The length does not have to exceed:

860mm for inside of residence
900mm for outside of residence
1100mm for public

Question 10

Define landing offset

Answer 10

The horizontal measurement equal to the landing dimension less one unit run

Question 11

Define landing drop

Answer 11

The difference between drop to line of flight and landing down.

This is the measurement of additional headroom that is yet to be attained

Question 12

Define landing down

Answer 12

The vertical measurement from upper floor to top of landing

Question 13

Define LFO

Answer 13

The horizontal measurement in the direction of the lower stair flight required to attain the Necessary headroom.

Question 14

Define margin return

Answer 14

The horizontal measurement from the bottom nosing to the vertical cut at the base of a housed or semi housed stringer

Question 15

Define Unit Line Length

Answer 15

The hypotenuse of unit rise and unit run triangle used to estimate the length of stinger material

For notched stinger multiply ULL by number of treads

For house or semi houses multiply ULL by number of risers

Question 16

Stair slope guidelines

Answer 16

38.1* max slope
30-35 comfort
19.4* min slope