H-5 Stairs Flashcards
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2 Rise Straight Gooseneck
where do the wedges go on a Stringer?
what type of Stringer
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Starting Easing with Cap
info
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2 Rise Straight Gooseneck with Tandem Cap
On a Dadoed Stringer , how deep the is the dado
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Tandem Cap
Fillets are where in a stair system
shaped to fit between balusters under the handrail and on top of buttress cap
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Right Hand Volute
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Mitred stringer
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Notched stringer
A balusters must have max opening between of opening?
100mm
A primary stairway between each floor in a dwelling unit must have a minimum between wall of faces what’s that distance
860 mm
A semi-housed or planted stringer has two parts:
A cut out stringer and a plain stringer. The plain stringer is a finished piece of wood attached to the wall. The cut out stringer is laminated to the plain stringer. The treads and the risers butt into the finished plain stringer.
a starting newel should
be extended into the flooring system, use dry material
anchorage
important to anchor posts securely in place. to support weight of people always grabbing them, starting newel should be extended through floor and securely blocked
Are handrails required when there’s only two risers within a dwelling unit
No
Balusters
small uprights under the handrail that close in the open side of the stairs for safety
building code requires balusters to be spaced such that a 4” diameter object cannot fit through it.
balustrade
complete unit of newel posts, handrail, balusters and buttress cap used to protect open side of staircases
buttress or string cap
used under balusters also called shoe rails or base rails
shaped to take the end of the baluster and are used in railings at the landings or on top of the stringers.
calculate stairwell rough opening
RO = run/rise x (headroom+floorthickness) + 75mm
Calculating stringer length
three methods
- multiply unit of bridge by number of treads
- multiply unit of bridge by number of rises
- number of linerier feet of stringer is equal to the number of treads (allow extra foot)
Calculating actual Rise
take total number of risers and divid by the total rise
Ex 2650/15=176.67mm or 177
Calculating run
using proportion rules the run can be calculated
- rise plus run = 450mm
rise= 177
177 + X=450
X=450-177
X(run)= 273mm
Circular stairs can be built from
Wood, concrete or steel
closed stairs
enclosed on both sides of stairway, handrail is attached to wall
Define double L stairs
A straight flight of stairs, with only 2-3 treads at right angle of main stairs at both top and bottom
Define wide L stairs
Consists of two straight flights at the right angles to each other
Define wide U stairs
They have 3 flights of stairs separated by 2 landings
Desired rise
use 7”
Does a Narrow u have steps in have steps in the landing on the back wall
double L stairs
straight flight with two or three treads at right angles to the main stairs.
Exterior concrete stairs
with more then two risers and two treads stairs must be supported on proper foundations that extend to firm bearing below frost heave. or hang stairs off main foundation wall as long as its 200mm thick (8”)
finished opening
horizontal distance from edge of the nosing at the upper landing to the opening edge of the finish at the other end of the stairwell
First step to layout the stringer ?
Plumb cut
for dadoed stringers, what is the depth of the dadoed notch?
for dadoed stringers, what is the depth of the dadoed notch?
Guards are how high of the landing surface?
1070mm above the landing and within a dwelling unit, guards can be 900mm high.
Guards for handrails code
are set at least 1070mm (42”) above landing surface 920mm (36”) above nosing line.guards must not be able to fit babies heads (100mm or 4”)
handrail
form the rail between newel posts
- meterial used must be graspable
- must be at least 2” clearance between handrail and wall
Handrail brackets must be spaced o/c max on a handrail?
1.2m
Handrail Heights on stairs and ramps must be between
865 mm and 1007 mm
Handrails are usually with a clear of how much from the inside of the rail to the wall?
50MM
Ergonomic Design
1) The clearance between a handrail and the surface behind it shall be not less than
a) 50 mm, or
b) where said surface is rough or abrasive, 60 mm.
2) All handrails shall be constructed so as to be continually graspable along their entire length
with no
obs ruction on or above them to break a handhold. (See Note A-9.8.7.5.(2).)
https://free.bcpublications.ca/civix/document/id/public/bcbc2018/bcbc_2018dbp9s98
handrails codes
required for all stairs more then two risers ( interior) and more then three exterior
Headroom
vertical distance from nosing line to underside of floor above
headroom
minimum headroom is measured vertically from nosing line to bottom of finished opening floor. must be at least 1950mm (77”) within dwelling units and 2050mm (80”) for all other stairs
How are curved stringers usually made?
Manufactured in a stair building plant using curved walls to form a jig and shipped to the job site.
How deep are the gains on a housed stringer?
about 1/2
How do you determine the number of risers?
Divided by the total rise by the desired rise. The fraction is rounded up if the decimal fraction is over point five. .05 and lower is always rounded down
how do you get rise per step?
after you have number of risers, divide number of risers by total rise for the rise per step
(2650mm/15=176.667mm) Rise per step= 177mm, round to the nearest millimetre
How is a housed stringer made?
Special adjustable templates are commercially available or a template can be made for the rise and run of the stair, which includes an allowanced for wedges to tighten the treads and the risers in place.Router is then used with the template to cut a gain (Recess) into the side of the stringers.
How is the floor thickness calculated?
Sum of ceiling finish + joist depth + subfloor thickness + finished flooring
How is the height of handrails measured?
vertically from the nosing line.
How many handrails are required if the dwelling unit stairwell is less than a 1100mm wide
It must have a handrail on one side
how many landings in a narrow “U” stairs?
how many flights of stairs in a wide “U” stairs?
- two landings for “U’
- three staircases in a wide “U”, two landings still
how to find total number of risers
total rise divided by the desired rise
- then round off because you cannot have partial step
Example:
total rise= 2650mm
desired rise = 180mm
2650/180= 14 .72 risers OR 15 risers
If you add the finished floor after you make your stairs what calculation must be done ?
Unit of rise - thickness of tread + finished floor
Improperly design stairs are problem and what matter
Tripping hazard
Is 180 mm rise and a 250 mm run good?
It’s the most comfortable 7 by 10
Know the following terms
total rise
total run
unit rise
unit run
tread
riser
nosing
nosing line ( Unit of bridge)
Tread depth
Headroom
finished opening
rough opening
stringer support board
stringer
You know these boys pg 3-4 H-5 LT1
L SHAPED WITH LANDING OPEN STAIRWELL LOOK LIKE
landings
used to change direction of stairs or break up total rise
- BCBC requires landings every 3.7 m vertically
Landings
- used to change directions in stairs
- or to break up total rise to create shorter flights of stairs
BCBC allows max total rise between landings to be 3.7 meters OR 2.4 meters for group B occupancy (hospitals etc…)
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Right Hand Volute?
long L stairs
consists of straight flight, with two or three treads at the top or bottom at right angle to main stairs .
Lubmer stringers
must be at least 225mm wide (9 1/4”) and have effective depth after cutting out rise and run of at least 90mm (3.5”) but be supported and secured at both top and bottom.
Materials used in a handrail must be?
graspable
max spacing of stringers
2’ OC for public stairs
3’ for stairs serving single dwelling units
minimum rise for private ad public stairs according to BCBC
public: max 180mm (7”) min 125 (5”)
private: max 200 (8”) min: 125mm (5”)
Minimum size of wooden stringer ?
2x10
although 2x12 is safer
Mono Stringers
Mouldings
used to trim under nosing to finish stairs cove or crown mouldings normally used
narrow U stairs
have two flights of stairs running opposite directions with a landing at the midway point.
Newel Posts
are the main supporting the balustrade
- starting newel used at bottom
- angel newel used at turn of stair
- landing newel used at top
nosing
projection of tread beyond face of riser board.
- BCBC requires maximum extensions of 25mm (1”)
- must be chamfered or rounded
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nosing line
imaginary line drawn above top edge of nosing
nosing returns
when stringer and riser have both been miter. exposed end of tread is shaped in the same way as the front nosing.
Nosing returns are used when
The stringer and riser have both been mitered
On a closed starwell what does a stight run look like
open stairs
have one or both sides open to a room or hallway. all open stairs have balustrade
OPEN STAIRWELL what does a double L look like ?
the minimum headroom measured from vertically from the nose and line must be at least
1950 mm stairs located within a dwelling 2050 mm for all other stairs
preferred angle of stairs
in between 30°-35°
10 and 7 stair has 35°
Private stairs
are interior stairs within a dwelling unit (residence) or exterior stair serving a single dwelling unit.
public stairs
all stairs not described as service or private stairs. public stairs include stairs in schools, parkades and other public buildings. need to be easy to use. PART THREE BCBC
Public stairs follow under what part of the building code
Part 3, are considered a means of egress
quarter turn stairs
stairs continue through corners
rise
vertical distance from one step to the next
riser
vertical board placed between treads.
Risers and treads should be nailed and
construction Adhesive
run
horizontal distance from one step to next
semi housed stringer define
has a planted on stringer that attached onto the finshed stringer
Service stair
Used to access only service rooms or spaces. (attic or mechanical rooms) cannot access any living space.
SPINDLE
Same a baluster. The upright piece the runs between the handrail and the tread.
Staircase formula?
Ratio proportion R.O. formula?
R.O.=
(UnitRun/UnitRise) x (headroom+floorthickness) + 75mm
FSO Unit Run
———————— = ————–
FT+Headroom Unit Rise
FSO=Finish stairwell opening
Ft= Floor thickness
stairway widths
Minimum stairway widths are found in part three of BCBC. determined by the type of occupancy and the occupant load when the stairway serves as part of exit.
stairwell rough opening
must be calculated before framing the opening in the floor. the length of the rough opening is dependent on the headroom required, floor thickness, and rise and run
rise and run triangle is proportionate to headroom opening triangles .
calculate rise and run then know headroom and floor thickness then finished opening can be calculated
Stinger overall min width?
235mm width and 38mm thinkness of thinkness of suppported along thier length
Stinger min. effective depth?
stringer
support for treads and risers BCBC requires to have effective depth of 90mm (3.5”) and overall depth no less then 235mm 9 1/4”
Stringer kicker?
Stringer size regulations?
Minimum effective depth of 90mm
Overall width of at least 235mm
stingers must be 25mm thick is supported along their length
38mm thick if not
Stringer spacing?
900mm max for stingers o/c spaing for single dewling unit
600mmm for stair other than dewlling units
stringer support board
also knows as hanger board, usually 19mm thick plywood nailed or screwed to the stringer and header of stairwell opening.
Stringers are also known as
Stair horse or carriage
The difference between a long “L” stair and a wide “L” stair is what?
A long L has a long flight and a short flight connected by landing or winders, while a wide L has two similar length flights at right angles to each other.
The difference between a long “L” stair and a wide “L” stair is what?
A long L has a long flight and a short flight connected by landing or winders, while a wide L has two similar length flights at right angles to each other.
The minimum run for private stairs is
255mm
The opening of the floor in the stairs is called what?
The Stairwell
The rough opening is how much longer then the finshed opening
3”/ 75mm
The slope of a stair also describes its comfort. What is the preferred angle of stairs
The rake angle is usually 30 to 35 degrees. 07 intense tear has a slope of approximately 35 degrees
The term nosing also refers to a
Moulding that can be applied to the edge of the floor
There is always one more riser than tread true or false
Ture
This is?
Housed stringer
total rise
vertical distance from finished floor to finished floor
total run
total horizontal distance of face of bottom riser to face of top riser
tread
horizontal board that forms step. tread depth is sum of run plus nosing
TREAD BRACKET?
Tread depth refers to the width of the tread not the length of the tread what is the minimum tread for private stairs
255 mm for private stairs. No nosing is required for runs over 235 mm and it’s not allowed at the maximum run at 355 mm
U STAIRS DEFINE
Unit of bridge
hypotenuse of rise and run triangle. used to calculate stringer depth
Unit of bridge formula?
Square root the √Rise^2+Run^2
√(177^2 + 273^2)
what adjustment is made at the bottom of the stringer and why?
Rise must be the same for each step, the first step is reduced by the tread thickness “dropping the stringer” Making the rise of the first step equal to the others
what adjustment is made at the bottom of the stringer and why?
Rise must be the same for each step, the first step is reduced by the tread thickness “dropping the stringer” Making the rise of the first step equal to the others
What are some handrail requirements ( 4 of them)
height - 865-965mm off of nosing line
Attached - with metal brackets , must provide 50mm clearance from wall
Attached 2 - solidly to framing members in the wall with good blocking.
handrails must be graspable - you can grip railing with ease
What are the main parts of balustrade?
Newel posts, handrail and balusters.
What are the minimum handrail requirements for stairways?
Provided on at least one side of stairs within dwelling units less than 1,100 mm wide. The handrail must be continuous along the length of the stairway, including landings except where interrupted by doorways, newels, or at changes in directions.
Handrails are not required for stairs having two risers within dwelling units.
What are the stair proportioning rules ?
unit rise + unit run =17”
twice rise plus run =24”
rise x run = 72”
What are winders?
Stairs with tapered treads
What causes squeaks in stairs?
stringers or treads rubbing against the wall, they must be either be spaced so they are not in contact or be fastened hard with adhesive and strong fasteners
What do all open stairwells have?
A finished balustrade
What does a housed stringer look like?
is routerd using a templete
uses wedge for
What does a L shaped stair look like? on a closed starwell
What does a U shaped stair look like? on a closed starwell
What does BC code require for effective depth and overall depth?
Effective depth of 90 mm ( 3 1/2” ) and an overall depth of not less than 235 ( 9 1/4” )
what does Stringer Support Board mean?
what does Unit of Bridge mean?
what does Effective Depth mean?
also known as ‘hanger board’, used to attach the stairs at the top to the floor opening
the hypotenuse of the rise and run triangle, used to calculate the stringer length
sometimes referred to as the ‘throat’, the material from the inside cut to the bottom of the stringer
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Dadoed stringer
What height should handrails be at?
865 mm to 1070 mm, measured vertically from the nosing line or from the surface of the ramp.
What in the minimum of the part of the stinger that rests on the header?
- 100mm
What is a Buttress cap?
used under balusters
What is a cleated stringer ?
The plain stringers have cleats nailed to them, instead of being notched out.
What is a cleated stringer most often used for?
Used as outdoor construction or as temporary stairs.
What is a cut out stringer
Your standard notched stringer
What is a mitred stringer?
Used in finished stairs. They can be used in combination with a housed stringer on the wall side. Where the riser and stringer meet on the open side, the end of the riser is bevelled and the plumb cut on the stringer is mitered.
What is a Newel post?
Newel posts are the posts supporting the balustrade.
What is a riser?
Vertical board between each tread.
what is a semi housed stringer
a notched out stringer with a plain stinger screwed on the side.
What is a semi-housed stringer?
A plain stringer laminated with a cutout stringer.
what is a trapped run?
is a condition where the total run of the stair is fixed
What is a tread?
The horizontal boards are stepped on in a set of stairs.
What is attached to the sides of a closed stairwell?
A handrail, on one or both sides
What is becoming more common to use to make stingers
LVL
What is commonly placed above a wide U stair?
A skylight to allow natural light
What is often used for carpeted stairs
1 inch thick OSB or plywood with a full bullnose
What is service stairs?
stairs to attic or utitly room
What is the cut out stringer used for
It is placed over the solid stringer
What is the difference between an “open stairwell” and a “closed stairwell”
Open stairwells have one or both sides open to a room or hallway. closed stairwells are enclosed on both sides.
What is the difference between wide L stair and and a long L Stair
A L wide stair has two similar flights of stairs at right angles to each other. A L long flight of stairs has a short flight connected by a landing or winding
What is the finished stairwell opening?
The horizontal distance from the edge of the nosing at the upper landing to the finished surface at the other end of the stairwell opening.
What is the headroom?
The headroom is the vertical distance from the nosing line to the underside of the floor above.
What is the material from inside of the cut to the bottom of the stringer called?
It is the effective depth. AKA the Throat.
What is the max total rise for a flight of stairs?
3.7m
What is the MAX. depth of thread?
It is the same as the run: 355 mm or 14” No nosing is required for runs over 235 mm, and it is not allowed at the maximum run of 355mm.
What is the maximum allowed difference between a rise and run on any two steps in a stairway
10 mm
What is the maximum difference rise or run between adjacent stairways
5mm
What is the maximum rise for private stairs
200 mm maximum and minimum rise of 125 mm. The most comfortable rides is about 180 mm or 7 in
What is the maximum slope allowed by code?
a slope rise of 200 and run of 255, which is 38.108 degree
What is the maximum slope of the BC building code
A slope rise of 200 and a run of 255 which is 38.108 degrees
What is the minimum size of wood and common size of wood used for wooden stringers?
2 x 10 minimum but 2 x 12 is more often used due to strength and 2” of effective depth.
What is the minimum thickness of a tread on a stairwell, if open rises are used and the distance exceeds 750mm what needs to happen
Lumber or plywood at a minimum thickness of 1in. If the distance exceeds 750 mm with no riser it has to be at least 38 mm of actual thickness
What is the nosing line?
An imaginary line drawn along the top edge of the nosings.
What is the nosing?
Nosing is the projection of the tread or floor beyond the face of the riser (“Nosing also refers to moulding that can be applied to the edge of the floor at a balcony”)
What is the preferred angle of stairs
30 to 35 degrees
What is the rise?
The vertical distance from one tread to the next.
What is the riser?
The Vertical board placed between the treads.
What is the rough stairwell opening?
The rough stairwell opening is framed before finishes or stairs are installed. The rough opening is typically 3” or 75 mm larger than the finished opening.
What is the run?
The horizontal distance from one riser to the next
What is the stringer support board?
Also known as the hanger board, is used to attach the stair at the top.
What is the stringer?
The stringer is the structural support for the treads and risers!
What is the Total Rise?
Vertical distance from finished floor to finished floor
What is the tread depth?
It’s the sum of the run plus nosing.
What is the tread?
The horizontal board that forms the step.
What is total run?
The total run is the horizontal distance from the face of the bottom riser to the face of top riser.
What is used to cut the template for housed stringers?
A router
What takes over procedure of formulas for stairs
BC building code minimum 255 mm
Whats a stair carriage?
Stringer
whats the differnce of a open or closed riser?
When is a landing required in a stairway?
When the total rise for the stairway is greater than 3.7 m
When is cleared stringers often used?
Outdoor construction
When woud you use a angle newel?
at a turn in a stair
WHERE A FILLET
Where is a Tandem Cap?
Where is the Rosette
Where so Fillets go?
where would you use a buttress cap?
under balusters, shaped to take the end of the balusters and can be directly on the floor of a landing or raised off the floor to form a bottom rail
WHERES A Quarterturn cap?
why are builders using LVL stock for stringers?
LVL is more dimensionally consistent and stronger than lumber
Why are narrow U stairs popular?
They are very compact
Why does a wide U stair have a space in the middle?
To allow light to reach all treads
Wide L stairs
consist of two straight flights at right angles to each other, with landing or winders at the change of direction
Wide U open stair look like?
has steps in the landing
Wide U stairs
have three flights of stairs separated by two landings has open centre that allows light to pass through.
Would a two-by-four work for a handrail
No because it’s not graspeble
right hand turnout
what is this?
Double L
What does a quarter-turn with winders look like staircase
Quarter turn with winders
Landing has to be how wide in relation to the tread?
landing must be as wide as the tread, with a minimum length of 860mm To 1100m
BCBC requires a landing at the top and bottom of stairs,
preferred angle of stairs
