Flashcards in 020205a - Single-Flight Straight Stairs Deck (123):
What is rise?
The vertical measurement or height from FINISHED FLOOR to FINISHED FLOOR.
What is unit rise?
The vertical rise measurement of each step. Unit rise is determined by dividing the rise by the desired number of risers.
What is run?
The horizontal distance covered by a stair, from the edge of the top step to the edge of the bottom step.
What are treads?
The horizontal member if a stair on which people place their feet.
What is a riser?
The vertical members of a stair placed behind treads that close the space between the treads.
What is a stringer?
The angular supporting members of a stair to which the treads and risers are fastened.
What is effective depth?
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.
What is stair flight?
A continuous series of steps with no intermediate landings.
What is line of flight?
An imaginary line that intersects the outer edges of all the nosings.
What is headroom in regard to stair framing?
The clear distance measured vertically from the line of flight to any obstruction above.
What is a stairwell?
The opening through which a stair will pass. This includes the opening in the floor frame as well as the surrounding walls.
What does finished opening dimensions mean in regard to stairs?
The horizontal, width, and length measurements of a stairwell, after all finishes have been applied and the stairs installed.
What does the rough opening refer to in regards to stair framing?
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.
What is a landing? in regards to stair framing
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.
What are some dangers associated with irregularities in either the unit rise or unit run of a stair?
tripping, loss of balance or falls.
What is the maximum and minimum unit rise for stairs?
The maximum is 200 mm and the minimum is 125 mm.
What is the maximum and minimum unit run for stairs?
The maximum is 355 mm and the minimum is 210mm.
Using a unit run at or near the minimum creates a steep stair. T or F
Most documentation recommends a stair slope of between 30 and 35 degrees. T or F
What is the highest slope by code for a stair?
What is the lowest slope by code for a stair?
What is the minimum tread width for a stair?
Nosings may be bevelled or rounded over. T or F
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.
The leading edge of the tread (nosing) may not project more than __ mm beyond the face of the riser.
25 mm (1")
Headroom clearance is measured from the flat surface of the tread. T or F
F. It is measured from the line of flight.
What is minimum clear height above any part of the line of flight to any overhead obstruction?
1950 mm and the full width of the stairs.
What is the minimum width between wall faces in a stairway?
860 mm. This is not recommended. Too small.
If a door is located at the top or bottom of a flight of stairs and swings towards the stairs, what is the condition?
That the full of arc its swing should be over a landing.
If the door swings aways from the stairs, a landing is not required between the door and the stairs. T or F
T at the top
What is the maximum vertical rise for a single flight stair is ___.
3700 mm. If the floor to floor measurement exceeds 3700 mm, a landing must be provided.
The effective depth of a botched stringer must be at least __ mm.
90 mm (3-1/2")
Stringers must be from at least 38 mm x 235 mm (2x10) material. T or F
When would one use mitred stringers?
If one or both sides of stairs are exposed.
What is a housed stringer?
Stringers which are routered out to receive the treads and risers.
A handrail is required on at least one side of stairs less than ____ mm in width.
A handrail is required on both sides of stairs if the width is 1100 mm or more. T or F
What is the maximum and minimum height above the line of flight for a hand rail?
MAX: 965 mm
MIN: 800 mm
Handrails should be attached to the walls with a minimum clearance of __ mm between the handrail and wall.
The maximum projection into the required width of a stairway for a handrail is ___ mm.
If an interior stair, including landings, is open on one or both sides, protection from falling must be provided. T or F
Guards may be omitted for stairs if the rise of the stair is ___ mm or less.
600 mm (24")
Stairs to unfinished basements do not require guards. T or F
If guards are constructed with vertical spindles, they should not be spaced more than ___ mm apart.
100 mm (4")
Any feature that would allow climbing is not allowed for a guard rail. T or F
A unit rise of approximately 180 mm or 7-1/8" is traditionally considered a good unit rise. T or F
What is head allowance?
Allowance for the attachment of the top of the stairs to the header joist.
The minimum head allowance that should be allowed is for the nosing and the thickness of the riser material. T or F
A semi-housed stringer consists of two separate stringers, what are they?
a notched (cut-out) stringer and a backing (supporting) stringer.
Backing stringers are usually made of __ mm thick material.
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.
19 mm, 12 mm
What are some methods of providing support for a straight stair?
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.
Landings are used to change the direction of travel and/or to create a rest platform. T or F
Landings may be considered an extra long tread. T or F
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).
Landings must be at least as wide and as long as the width of the stairs they connect. T or F
Landing length need not exceed ___ for inside a residence, ___ mm outside a residence.
Landing length need not exceed ___ mm for public stairs that are wider than 1100 mm.
Straight stairs require a landing when the total rise exceeds ___ mm or in public buildings to create a rest platform.
Ideally, the subfloor should be left to project into the top of the stairwell opening. T or F
The subfloor should overhang an amount equal to the nosing plus riser thickness. T or F
The run of a flight of stairs is a horizontal measurement from the ___ to the ___.
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.
Describe the term headroom as it refers to stairs.
Headroom is the vertical measurement from the line of flight to any obstruction.
What is the most common cause of units rise being unequal in older homes?
A new flooring material applied over the existing flooring either on the upper or lower floors.
What are the maximum and minimum unit rise for a residence?
MAX: 200 mm
MIN: 125 mm
What are the maximum and minimum unit run for a residence?
If the minimum unit un is used, what must be provided?
A nosing of at least 25 mm must be provided to meet the minimum tread width of 235 mm.
What stair slopes do most textbooks recommend?
30 to 35 degrees
Nosings are not required if the unit run is over ___ mm.
What is the minimum tread width?
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?
14 mm radius curve
What is the most likely cause of tripping when ascending stairs?
What is the maximum rise for a single flight of stairs?
What is the minimum effective depth required for a notched stringer?
What is the minimum size of material that can be used for a notched stringer?
38 mm x 235 mm (10 x 2)
Which style of stairs utilizes router grooves and tapered wedges to support the treads?
Handrails are not required for stairs leading to an unfinished basement. T or F
Guards should be installed at a minimum height of ___ mm (public) and ___ mm (residential) above a landing.
PUBLIC: 1070 mm
RESIDENTIAL: 900 mm
What two situations must be avoided if a guard is constructed with uniformly spaced spindles and an upper handrail?
A 100 mm diameter ball should not be able to pass through the spindles and the railing should not have features that allow climbing.
A unit rise of ___ mm or inches is considered good.
180 mm or 7-1/8"
The National Building Code establishes limits for unit run calculations. T or F
What unit rise to unit run ratio is used to produce a 32.5 degree stair?
How is the length of material required for a notched stringer calculated?
Number of treads by the unit line length.
How is the length of material required for a backing stringer calculated?
The number of risers by the unit line length.
When using the framing square to lay out stairs, the unit of rise should be held on the ___ of the square.
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.
the thickness of one tread above the layout line.
The vertical cut at the bottom of a backing stringer is called a/an _____.
Margin return or Bottom easement
What should be done once on stringer is cut out and the other is to be traced?
The cut stringer should be flipped so that the layout side is traced.
The tread width is equal to ___ plus ___.
The unit run plus the nosing
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?
Twice the wall finish thickness
Twice 6mm (1/4") for fitting allowance
Twice the backing stringer thickness
What should be done periodically during the assembly of stairs?
Measure the diagonals to check for squareness.
All units of rise and run must be uniform throughout the stair. T or F
What is an open stair?
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.
What are closed stairs?
Closed stairs are entirely enclosed between full height walls.
What is a balustrade?
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.
What is a baluster?
The small vertical members (spindles) that support the handrail and partially close the open side of the stair for safety.
The ___ is the angular top rail of a balustrade.
___ posts are the large vertical members (posts) used to support the balustrade.
Landings should be at least as wide and as long as the width of the stairs in which they occur. T or F
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
A landing is always required at the bottom of a stair. T or F
If a door swings toward a stair, the full width of its arc must NOT be over a landing. T or F
F. The full width of the arc MUST be over a landing.
The ___ of the level cut must have full bearing on the landing platform.
What is a landing?
A small structural floor frame that supports a flight of stairs either at the top or bottom.
Minimum risers within a dwelling interior flight?
Uniform height tolerances regarding risers in a stair system?
Uniform height tolerances regarding treads in a stair system?
Tread nosing - bevelled or rounded edge. Min: ___ mm Max: ___ mm
Min: 6mm Max: 14mm
Clear height over landing. Private:
Private: 1950 mm
Landing length need not exceed ____ mm for public stairs that are wider than 1100 mm.
The handrail should be on the shortest route for stairs that turn. T or F
On straight stairs, the handrail should be on the right side wall when ascending the stairs. T or F
Handrail brackets should be attached to the wall at not more than ___ apart along the length of the wall.
A handrail bracket should be installed no further than 300 mm from each end. T or F
Max space for space between openings in a guard system?
100 mm (4")
Max space for space between openings in a guard system for an INDUSTRIAL building?
Minimum stringer depth:
235 mm (2 x 10)
Min stringer thickness:
Max space allowed for space between stringers for a private stair? All other stairs?
Max: 900 mm
All other stairs: 600 mm
Max space for stringers with riser material supporting the tread.
What is 1200 mm
Minimum tread thickness?
Minimum tread thickness if open risers are used?
A straight stair is:
a stair that continues uninterrupted from one floor to another.