020205a - Single-Flight Straight Stairs

Question 1

What is rise?

Answer 1

The vertical measurement or height from FINISHED FLOOR to FINISHED FLOOR.

Question 2

What is unit rise?

Answer 2

The vertical rise measurement of each step. Unit rise is determined by dividing the rise by the desired number of risers.

Question 3

What is run?

Answer 3

The horizontal distance covered by a stair, from the edge of the top step to the edge of the bottom step.

Question 4

What are treads?

Answer 4

The horizontal member if a stair on which people place their feet.

Question 5

What is a riser?

Answer 5

The vertical members of a stair placed behind treads that close the space between the treads.

Question 6

What is a stringer?

Answer 6

The angular supporting members of a stair to which the treads and risers are fastened.

Question 7

What is effective depth?

Answer 7

A measurement made at right angles to the slope of the stair from the rear junction of the riser and tread to the underside of a noticed stringer. The is the weakest section of the stringer.

Question 8

What is stair flight?

Answer 8

A continuous series of steps with no intermediate landings.

Question 9

What is line of flight?

Answer 9

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

Question 10

What is headroom in regard to stair framing?

Answer 10

The clear distance measured vertically from the line of flight to any obstruction above.

Question 11

What is a stairwell?

Answer 11

The opening through which a stair will pass. This includes the opening in the floor frame as well as the surrounding walls.

Question 12

What does finished opening dimensions mean in regard to stairs?

Answer 12

The horizontal, width, and length measurements of a stairwell, after all finishes have been applied and the stairs installed.

Question 13

What does the rough opening refer to in regards to stair framing?

Answer 13

The horizontal, width and length measurements of the floor frame members around a stairwell opening before any finishes have been applied or stairs are installed.

Question 14

What is a landing? in regards to stair framing

Answer 14

The platform or level floor area at the top, or bottom of a flight of stairs. May also be an intermediate level platform within a straight flight or at a position where two stair flights change direction.

Question 15

What are some dangers associated with irregularities in either the unit rise or unit run of a stair?

Answer 15

tripping, loss of balance or falls.

Question 16

What is the maximum and minimum unit rise for stairs?

Answer 16

The maximum is 200 mm and the minimum is 125 mm.

Question 17

What is the maximum and minimum unit run for stairs?

Answer 17

The maximum is 355 mm and the minimum is 210mm.

Question 18

Using a unit run at or near the minimum creates a steep stair. T or F

Answer 18

T

Question 19

Most documentation recommends a stair slope of between 30 and 35 degrees. T or F

Answer 19

T

Question 20

What is the highest slope by code for a stair?

Answer 20

43.6 degrees

Question 21

What is the lowest slope by code for a stair?

Answer 21

19.4 degrees

Question 22

What is the minimum tread width for a stair?

Answer 22

235

Question 23

Nosings may be bevelled or rounded over. T or F

Answer 23

T. As long as the minimum tread depth is not reduced by more than 14 mm. Regardless of the tread width or thickness, the curve or bevel should not reduce the effective tread by more than 25 mm.

Question 24

The leading edge of the tread (nosing) may not project more than __ mm beyond the face of the riser.

Answer 24

25 mm (1”)

Question 25

Headroom clearance is measured from the flat surface of the tread. T or F

Answer 25

F. It is measured from the line of flight.

Question 26

What is minimum clear height above any part of the line of flight to any overhead obstruction?

Answer 26

1950 mm and the full width of the stairs.

Question 27

What is the minimum width between wall faces in a stairway?

Answer 27

860 mm. This is not recommended. Too small.

Question 28

If a door is located at the top or bottom of a flight of stairs and swings towards the stairs, what is the condition?

Answer 28

That the full of arc its swing should be over a landing.

Question 29

If the door swings aways from the stairs, a landing is not required between the door and the stairs. T or F

Answer 29

T at the top

Question 30

What is the maximum vertical rise for a single flight stair is ___.

Answer 30

3700 mm. If the floor to floor measurement exceeds 3700 mm, a landing must be provided.

Question 31

The effective depth of a botched stringer must be at least __ mm.

Answer 31

90 mm (3-1/2")

Question 32

Stringers must be from at least 38 mm x 235 mm (2x10) material. T or F

Answer 32

T

Question 33

When would one use mitred stringers?

Answer 33

If one or both sides of stairs are exposed.

Question 34

What is a housed stringer?

Answer 34

Stringers which are routered out to receive the treads and risers.

Question 35

A handrail is required on at least one side of stairs less than ____ mm in width.

Answer 35

1100mm

Question 36

A handrail is required on both sides of stairs if the width is 1100 mm or more. T or F

Answer 36

T

Question 37

What is the maximum and minimum height above the line of flight for a hand rail?

Answer 37

MAX: 965 mm MIN: 800 mm

Question 38

Handrails should be attached to the walls with a minimum clearance of __ mm between the handrail and wall.

Answer 38

50 mm

Question 39

The maximum projection into the required width of a stairway for a handrail is ___ mm.

Answer 39

100 mm

Question 40

If an interior stair, including landings, is open on one or both sides, protection from falling must be provided. T or F

Answer 40

T

Question 41

Guards may be omitted for stairs if the rise of the stair is ___ mm or less.

Answer 41

600 mm (24")

Question 42

Stairs to unfinished basements do not require guards. T or F

Answer 42

T

Question 43

If guards are constructed with vertical spindles, they should not be spaced more than ___ mm apart.

Answer 43

100 mm (4")

Question 44

Any feature that would allow climbing is not allowed for a guard rail. T or F

Answer 44

T

Question 45

A unit rise of approximately 180 mm or 7-1/8" is traditionally considered a good unit rise. T or F

Answer 45

T

Question 46

What is head allowance?

Answer 46

Allowance for the attachment of the top of the stairs to the header joist.

Question 47

The minimum head allowance that should be allowed is for the nosing and the thickness of the riser material. T or F

Answer 47

T

Question 48

A semi-housed stringer consists of two separate stringers, what are they?

Answer 48

a notched (cut-out) stringer and a backing (supporting) stringer.

Question 49

Backing stringers are usually made of __ mm thick material.

Answer 49

38 mm

Question 50

Cut-out or notched stringers may be made from __ mm solid material or from strips of plywood. The minimum thickness fro the notched stringer is __ mm.

Answer 50

19 mm, 12 mm

Question 51

What are some methods of providing support for a straight stair?

Answer 51

Introduce a third central stringer, nail into the wall studs or utilize supporting walls, adding additional 2x4s on the inside of the stringers parallel to the effective depth.

Question 52

Landings are used to change the direction of travel and/or to create a rest platform. T or F

Answer 52

T

Question 53

Landings may be considered an extra long tread. T or F

Answer 53

T

Question 54

A minimum of _ risers must be provided between landings or between a landing and the top or bottom of the stair (except in private residence).

Answer 54

THREE

Question 55

Landings must be at least as wide and as long as the width of the stairs they connect. T or F

Answer 55

T

Question 56

Landing length need not exceed ___ for inside a residence, ___ mm outside a residence.

Answer 56

860 mm | 900 mm

Question 57

Landing length need not exceed ___ mm for public stairs that are wider than 1100 mm.

Answer 57

1100 mm

Question 58

Straight stairs require a landing when the total rise exceeds ___ mm or in public buildings to create a rest platform.

Answer 58

3700 mm

Question 59

Ideally, the subfloor should be left to project into the top of the stairwell opening. T or F

Answer 59

T

Question 60

The subfloor should overhang an amount equal to the nosing plus riser thickness. T or F

Answer 60

T

Question 61

The run of a flight of stairs is a horizontal measurement from the ___ to the ___.

Answer 61

The run of a flight of stairs is a horizontal measurement from the EDGE OF THE TOP NOSING to the EDGE OF THE BOTTOM NOSING.

Question 62

Describe the term headroom as it refers to stairs.

Answer 62

Headroom is the vertical measurement from the line of flight to any obstruction.

Question 63

What is the most common cause of units rise being unequal in older homes?

Answer 63

A new flooring material applied over the existing flooring either on the upper or lower floors.

Question 64

What are the maximum and minimum unit rise for a residence?

Answer 64

MAX: 200 mm MIN: 125 mm

Question 65

What are the maximum and minimum unit run for a residence?

Answer 65

MAX: 355 MIN: 210

Question 66

If the minimum unit un is used, what must be provided?

Answer 66

A nosing of at least 25 mm must be provided to meet the minimum tread width of 235 mm.

Question 67

What stair slopes do most textbooks recommend?

Answer 67

30 to 35 degrees

Question 68

Nosings are not required if the unit run is over ___ mm.

Answer 68

235 mm

Question 69

What is the minimum tread width?

Answer 69

235 mm.

Question 70

If 38 x 235 mm material is used as treads, what is the largest radius of curve that can be routered onto the front edge of the nosing?

Answer 70

14 mm radius curve

Question 71

What is the most likely cause of tripping when ascending stairs?

Answer 71

excessive nosing

Question 72

What is the maximum rise for a single flight of stairs?

Answer 72

3700 mm

Question 73

What is the minimum effective depth required for a notched stringer?

Answer 73

90 mm

Question 74

What is the minimum size of material that can be used for a notched stringer?

Answer 74

38 mm x 235 mm (10 x 2)

Question 75

Which style of stairs utilizes router grooves and tapered wedges to support the treads?

Answer 75

housed

Question 76

Handrails are not required for stairs leading to an unfinished basement. T or F

Answer 76

T

Question 77

Guards should be installed at a minimum height of ___ mm (public) and ___ mm (residential) above a landing.

Answer 77

PUBLIC: 1070 mm RESIDENTIAL: 900 mm

Question 78

What two situations must be avoided if a guard is constructed with uniformly spaced spindles and an upper handrail?

Answer 78

A 100 mm diameter ball should not be able to pass through the spindles and the railing should not have features that allow climbing.

Question 79

A unit rise of ___ mm or inches is considered good.

Answer 79

180 mm or 7-1/8"

Question 80

The National Building Code establishes limits for unit run calculations. T or F

Answer 80

T

Question 81

What unit rise to unit run ratio is used to produce a 32.5 degree stair?

Answer 81

7:11

Question 82

How is the length of material required for a notched stringer calculated?

Answer 82

Number of treads by the unit line length.

Question 83

How is the length of material required for a backing stringer calculated?

Answer 83

The number of risers by the unit line length.

Question 84

When using the framing square to lay out stairs, the unit of rise should be held on the ___ of the square.

Answer 84

tongue

Question 85

For a notched stringer, to establish the cut line at the bottom or floor, a line is drawn equal to ____ above the initial layout line.

Answer 85

the thickness of one tread above the layout line.

Question 86

The vertical cut at the bottom of a backing stringer is called a/an _____.

Answer 86

Margin return or Bottom easement

Question 87

What should be done once on stringer is cut out and the other is to be traced?

Answer 87

The cut stringer should be flipped so that the layout side is traced.

Question 88

The tread width is equal to ___ plus ___.

Answer 88

The unit run plus the nosing

Question 89

If the wall-to-wall dimension is known, what deductions must be made in order to calculate the length of treads and risers for a semi-housed stair?

Answer 89

Twice the wall finish thickness Twice 6mm (1/4") for fitting allowance Twice the backing stringer thickness

Question 90

What should be done periodically during the assembly of stairs?

Answer 90

Measure the diagonals to check for squareness.

Question 91

All units of rise and run must be uniform throughout the stair. T or F

Answer 91

T

Question 92

What is an open stair?

Answer 92

Open stairs have one or two sides open to a room or hallway. Short walls or guards on the open sides of the landings do not close the stairs. Not full walls.

Question 93

What are closed stairs?

Answer 93

Closed stairs are entirely enclosed between full height walls.

Question 94

What is a balustrade?

Answer 94

The combination of handrail, newel posts and spindles or balusters to protect the open sides of the stair and landings must conform to the code regulations for guards.

Question 95

What is a baluster?

Answer 95

The small vertical members (spindles) that support the handrail and partially close the open side of the stair for safety.

Question 96

The ___ is the angular top rail of a balustrade.

Answer 96

Handrail

Question 97

___ posts are the large vertical members (posts) used to support the balustrade.

Answer 97

Newel posts

Question 98

Landings should be at least as wide and as long as the width of the stairs in which they occur. T or F

Answer 98

T

Question 99

A landing should be provided at top and bottom of a stair, except that, if a door swings away from the top of a stair, a landing is not required. T or F

Answer 99

T

Question 100

A landing is always required at the bottom of a stair. T or F

Answer 100

T

Question 101

If a door swings toward a stair, the full width of its arc must NOT be over a landing. T or F

Answer 101

F. The full width of the arc MUST be over a landing.

Question 102

The ___ of the level cut must have full bearing on the landing platform.

Answer 102

Heel

Question 103

What is a landing?

Answer 103

A small structural floor frame that supports a flight of stairs either at the top or bottom.

Question 104

Minimum risers within a dwelling interior flight?

Answer 104

3

Question 105

Uniform height tolerances regarding risers in a stair system?

Answer 105

5-10 mm

Question 106

Uniform height tolerances regarding treads in a stair system?

Answer 106

5-10 mm

Question 107

Tread nosing - bevelled or rounded edge. Min: ___ mm Max: ___ mm

Answer 107

Min: 6mm Max: 14mm

Question 108

Clear height over landing. Private: | Public:

Answer 108

Private: 1950 mm Public: 2050

Question 109

Landing length need not exceed ____ mm for public stairs that are wider than 1100 mm.

Answer 109

1100 mm

Question 110

The handrail should be on the shortest route for stairs that turn. T or F

Answer 110

T

Question 111

On straight stairs, the handrail should be on the right side wall when ascending the stairs. T or F

Answer 111

T

Question 112

Handrail brackets should be attached to the wall at not more than ___ apart along the length of the wall.

Answer 112

1200mm

Question 113

A handrail bracket should be installed no further than 300 mm from each end. T or F

Answer 113

T

Question 114

Max space for space between openings in a guard system?

Answer 114

100 mm (4")

Question 115

Max space for space between openings in a guard system for an INDUSTRIAL building?

Answer 115

200 mm

Question 116

Minimum stringer depth:

Answer 116

235 mm (2 x 10)

Question 117

Min stringer thickness:

Answer 117

38 mm

Question 118

Max space allowed for space between stringers for a private stair? All other stairs?

Answer 118

Max: 900 mm All other stairs: 600 mm

Question 119

Max space for stringers with riser material supporting the tread.

Answer 119

What is 1200 mm

Question 120

Minimum tread thickness?

Answer 120

25 mm

Question 121

Minimum tread thickness if open risers are used?

Answer 121

38 mm

Question 122

A straight stair is:

Answer 122

a stair that continues uninterrupted from one floor to another.

Question 123

Handrails are not required on stairs if:

Answer 123

they have less than three risers and/or they service unfinished basements.