H-3 Task 1 Flashcards
1) what is the minimum sill plate allowed by bc building code?
38x89mm (2x4), 2x6 is used often instead
2) After the sill plate is anchored to the foundation, what transfers through it?
Live and dead loads of the floor, wall, and roof to the concrete
3) in addition to transferring the wood frame building weight to the foundation, what are other functions of a sill plate?
Anchors the building to the foundation for wind and siesmic loads.
Also used to provide lateral support for the foundation walls.
4) What kind of buildings can experience great stresses due to heavy wind loads?
Tall narrow buildings, making building anchorage very important.
5) what is the minimum depth anchor bolts go into the concrete?
100mm (4”) should have as much side concrete coverage as feasible
6) Whats the diameter for longer bolts?
Diameter for shorter bolts?
(Anchor bolts)
Long bolts 1”
Shorter usually 1/2” or 5/8”
Lengths come in various sizes, short as 6” up to several feet long
7) foundation walls are often stepped when contructed on sloping sites, what does the stepped foundation require in terms of framing?
Pony walls to support the floor joists where the top of the foundation wall is shorter
8) what is another term for concrete column?
What shape is concrete column usually?
Piers
Concrete columns are usually round
9) whats the minimum nominal size of wood columns?
6x6, they cannot be smaller in actual dimension than the width of the beam they are supporting
10) what is minimum diameter for steel column?
Minimum diameter of 3”
11) Whats the minimum diameter for wood column in a carport?
Carports may be reduced to 4x4 nominal dimension
12) whats the minimum diameter for a round wooden column?
Must not be smaller than 7-1/4” diameter
13) What can wood columns be made from?
Solid lumber or built up from 2x6
Built up are more common than solid lumber, solid lumber columns are expensive and tend to twist and check as they dry
14) what type of lumber columns do engineers prefer?
PSL or Glue-laminated
Often specified in engineered buildings
Prefer these cause their strucural properties can be more carefully controlled
What gives a built up column an advantage over solid 6x6?
Column must fully support the beam, so a 5ply 2x10 would need a 5ply 2x6 column
5ply 7-1/2”
Advantage steel column has over wood column?
Can be used to correct settlement and shrinkage of framing members
How is the steel column secured to the beam and basement slab?
Lag screws into the beam, base of the column is often secured by casting into the basement slab
What are 5 beams for framing?
- solid wood
- built up
- glue laminated
- steel
- engineered
Why is solid wood beams used, compared to other beams?
Aesthetic design purposes such as timber frame.
Sizing of solid wood beams must be done using engineering tables
How are built up beams determined?
By consulting the BC Building Code, eliminates the need for expensive engineering
Normally nail-laminated together or bolted
Where are glue laminated beams built?
Must be manufactured in approved plants. They cannot be built on-site.
What are standard thicknesses for glue-laminated?
What are the depth of these beams?
80mm and 130mm thickness
228mm to 456mm depth
These beams allow for large spans and are able to carry heavy loads.
Which steel flange beams are used for wood frame construction?
Wide flange. Standard flange is narrow and sloped, making attaching wood joists difficult
What is the depth and weight of a W150 x 22 steel beam?
Depth is 150mm
Weight is 22 kg per lineal metre
What do the depths of steel beams vary from?
150mm to 310mm (W150-W310)
What two beams can be designed by carpenters using the design table in the BC Building Code book?
Glue-laminated and steel beams
What are 3 common engineered beams?
Laminated veneer lumber (LVL)
Parallel strand lumber (PSL)
Girder truss beams
What advantages does engineered beams have compared to built-up and solid lumber beams?
Allows longer spans
Who would design a laminated veneer lumber beam?
Professional engineer, bc code book doesnt have design tables for lvl beams
Difference between psl and lvl?
Similar to each other but psl uses strands of veneer and lvl uses sheets of veneer
What are thicknesses of psl?
Widths?
4” and 6”
9-1/4” to 16”
Can you build up psl beams like lvl’s?
Using side by side
No as they are thicker already, heavy that cranes usually handle psl beams
Where would you use a girder truss beam?
Roof structures, also be used as beams in walls
What factors into size and shape of girder truss beam?
Who designs these trusses?
Limited by the creativity and budget of the designer
Registered engineer designs
What must you keep in mind while constructing floor joists?
Minimize deflection and excessive vibration
What are the dimensions of lumber you can use for floor joists?
2x4 to 2x12
Span tables have 2x4, but theyre only used for very short spans.
How closely must you follow the direction of engineered joists and beams as indicated on drawings?
Very closely, a missing stiffener or simply installing a joist upside down can cause a structural failure
i-joists have a cord and a web, what is the cord made from, and whats is the web made from?
Cord is LVL, PSL, S4S lumber
Web is plywood or OSB
Can you use different brands or interchange i-joists?
No, each manufacturer uses a patented system and specifcations
Are i-joist spans in the code book?
No, the span is dependent upon its depth, chord width, and spacing
What is open web joists made from?
(Chord and web)
How do these joist hang on the wall?
Wooden cords and wooden webs or
Wooden cords and steel webs
“Top hung” top cord is sitting on the plate, bottom cord hangs
No question:
Parallel cord trusses must be fully braced before any loading is permitted, so fully brace each truss before laying the next truss
Plywood vs OSB
Which is stronger in shear strength?
OSB is twice as strong
Plywood vs OSB
Which is stiffer?
Which is lighter?
Plywood is 10% stiffer and 15% lighter
Plywood vs OSB
Tongue and groove, what are thier widths?
Not thickness, not length
OSB covers 48”, plywood covers 47-1/2”
Plywood vs OSB
Which is more economical?
OSB, also more “greener” in the way its produced
Plywood vs OSB
Both are subject to swelling, which is got it worse?
OSB, not as resistant to swelling. Plywood will swell too, but probably return to its original size
What factors into floor stiffness?
When using underlay, second layer of sheathing. What offset for joists be?
Minimum
Thickness of plywood influences it
8” (200mm)
What is the maximum clear span between rows of twist restraint for joists?
(Bridging, blocking)
7’
When using strapping method of twist restraint, what helps act as strapping?
Gypsum board will help, but bridging is still the best method
When cutting bridging pieces to length, how much should you account for at the bottom of the joist?
1/4” less than full length to avoid the bridging being longer and interfering with the drywall or sheathing
