H3 - Build Floor Systems Flashcards
N DECK
What is a sill plate?
Lowest member of a wood frame.
What is the function of anchorage?
Anchor bolts and sill plate make the connection between the foundation and the rest of the structure. Keeps building attached during earthquake or high winds.
What are anchor bolts designed to resist?
Pull out
What kind of walls are required to support floor joists in step foundations, where the top of the foundation wall is shorter?
Poly walls
What is a column?
An upright member supporting a load. It’s also known as a post.
What is the minimum nominal size of a wood column?
6 x 6, but they cannot be smaller in actual dimension than the width of the beam they are supporting.4x4 may be used to support carports.
What is the minimum diameter of a steel column?
Min. Diameter is 3 inches.
What is the minimum size of a round column?
7 and 1/4 diameter
Why are built-up columns more common than solid lumber as column use?
Solid lumber columns are expensive and tend to twist and check as they dry.
What is the advantage of Glue-laminated beams?
Allow for large spans and are able to carry heavy loads. Two standard thicknesses: 80 mm130 mm.Depth varies from: 2228 mm to 456 mm. Maximum span for deepest and thickest is 11.02 m. 36’2”
A W150 x 22 beam means what?
W150 = 150 mm22 = 22 kg per lineal metre.
What is an Laminated Veneer Lumber beam?
An engineered beam, made from sheets of veneer. LVL is usually 1 3/4 thick and comes in widths from 7 1/2 to 16”
What is Parallel strand beams?
Similar to LVL, made from strands of veneer, engineered.4 & 6 inch thick, width vary from 9 1/2 to 16”
What is a girder truss beam?
Common in the roof structure, supports the roof load above, up to 3 ply configuration.
What is the main function of engineered beams and floor joists?
To span between then beams and support the floor sheathing
Which part of the code book must an engineer use to design floor systems?
Part 4 - which specifies the maximum limits of movement for structural members within the systems.
How do you store engineered products?
handle with care, store in a well supported and level or plumb position
What engineered lumber is most common?
The I-joist. Chords are made from lvl, psl or s4sThe webs are made from Plywood, OSB and joined to the chord with a special edge finger joint. The webs are glued to the chords using water proof gliue.Maximum length is 66’
True or False, I joists are in the BC building code?
False
What is another name for open web-joists?
Paralell cord floor trusses
How far can an open web hoist span?
Over 50 feet.
Which type of building use long anchor bolts?
The building which uplift can be created by wind forces & lateral forces caused by wind and seismic events.
What forces are anchor bolts designed to resist?
To support floor and aor wall framing and to anchor the framing to the foundations.
Why is a standard flange steel beam not used in construction?
Because of it’s narrow and sloped flange.
What size of post is used to support a 5-ply built-up wood beam?
5 ply 2 by 6 or rough cut 8 by 8
What do “LVL and “PSL” stand for?
Laminated Veneer Lumber and Parallel Strand Lumber.
Can I joists be designed using tables in the BC building code?
No, need an engineer approval.
What are the three choices for twist restrain given in the building code for floor joist design?
Strapping, briding, strapping AND bridging.
What type of support does bridging provide?
It resists the twisting of the joints as they dry. It distrubes the load from one joint to adjacent joists.
What materials can be used as strapping?
1 by 3 or panel-type ceiling finish (gypsum etc.)
List two types of matched edges used with floor sheathing?
T and G and Shiplap
When planning a floor system, how critical is the elevation of the floor?
If it’s too low, plumbing may not have enough to connect to the sewer system or septic tank.
How high above the finished grade must the concrete wall be?
150 mm, in the case of siding that can be affected by moisture, 200 mm.
How much lower must decks and porches which serve the interior floor be?
150 mm lower
What may result from back-filling before the floor frame i s completely sheathed and braced?
May result in the foundation cracking and falling.
Is the floor system laterally supported when pony walls are used between the sill plate and the floor system?
It is considered laterally unsupported at the top by BC Code
When using the floor system as lateral support, how must you secure it to the sill plate above foundation walls?
Each floor joist is spiked with two toe nails and the boxing rim joist is spiked to the sill plate with angled nails spaced no more than 24” O.c.Boxing joists may be required every 150 mm in high seismic locations.
Sill plates must be anchored to resist what?
Uplift and lateral load.
Whatrt is the maximum spacing for anchor bolts?
2.4 m (8’oc) for 15.9 mm diameter bolts and 1.7 m 5’7 oc for 12.7mm bolts in high-wind or seismic areas.
Within 0.5 m of each foundation corner, how many bolts are required?
One
How many bolts per foundation step and wall panel are needed? (anchor bolt)
2
What is a SIll Gasket?
Protection of the sill plate from the top of foundation wall, prevents.
How is air barrier made under the sill plate of the foundation wall?
Caulking at the inside joint between the sill plate and concrete foundation wall.
What does 1/360 deflection mean?
This means members will sag 1 mm in 3560 mm or 1 inch in 360 inches. for a 16’ beam or floor joist, the allowable deflection will be over 1/2”.
What is the clear span of a joist or beam?
The Horizontal distance from shear point to shear point.
What is the shear point?
The shear point is where the beam or joist leaves it suopport.
Beams used in single spans deflect more than what?
Beams that are continuous over two or more spans.
How can you increase the stiffness of a beam?
Cantilever will reduce deflection and increase stiffness, as a cantilvered beam deflects between its supports, the cantilevered portion of the beam rises.
What is the supported joist length?
The amount of load that a beam carries is propportional to the amount of the floor it supports. The amount of floor is the “SJL”, which is a distance equal to the length of joist suppported by the beam.
Aligning all framing members (studs, floor joists, etc) is it code or not?
Not good, but good practice.
What does using double wall paltes do?
In-wall framing - allows joists and roof trusses to land between stud spaces. The double plate acts as a beam and transfers the load to the adjacent studs.
When the floor system supports a bearing wall, the support for the wall must be continuous to the foundation. True or False
True
If the bearing wall is perpendicular to the joists, the supported wall must be directly over the supporting wall or offset by how much?
3’ for ceiling load and 2’ for floor loads.
Do non bearing walls perpendicular to the floor joists have to be supported by extra joists?
Nonbearing walls perpendicular to the floor joists do not have to be supported by extra joists.
How must plywood be installed on joists?
90 degrees to the joist direction and the end joints for adjacent rows staggered.1.55 5/8 thick ply can be used on joists over 400 mm 16” ocand 18.4mm 3/4” for joists spacing at 600 mm 24” oc
How much oriented strand board be installed?
Osb must be installed with the face orientation 90 degrees to the joist direction and the end joints staggered.15.9mm 5/8 OSB can be used on joists at 400 mm 16” o.c and 19 mm 3/4 for joists spacing at 600 mm 24” oc
How much solid lumber flooring be installed?
Must be installed at an angle not less than 45 degrees to the floor and all board ends must be supported. Typically ship lap is used when solid lumber subfloor is desired.
How much solid lumber flooring be installed?
Must be installed at an angle not less than 45 degrees to the floor and all board ends must be supported. Typically ship lap is used when solid lumber subfloor is desired.Not often used: 5 1/2 and 71/4 widths and 3/4” thick. Boards wider than 1 x 8 are not approved for use as sheathing due to excess shrinkage
What type of building uses long anchor bolts?
High Rise Construction
What are the two most important factors when installing anchor bolts?
Concrete consolidation and location
What is the depth of a W250 x 33 beam?
250 mm (10”)
What is a shear point?
The point where the beam or joist leaves it’s support
Why are footings for columns larger than footings for walls?
Point loads imposed on the footing are greater and need to be spread over a greater area.
A carpenter can design three types of beams using the (BC Building Code?)
- Built up wood. 2. Steel. 3. Gluelam?
Define the term - Supported Joist Length
Amount of floor that a beam supports.
What is the difference between building width and clear span?
Building width is the ENTIRE width of the building.Clear span is the distance between SHEAR points.
How does the cantilever effect help to support beams?
Downward deflection on one side of the support causes uplift on the other side of the support.
What is the supported joist length for a single centred beam if the building is 6.34 M wide?
3.17 M
How can a building that includes two floor levels be built with beams designed to support only one floor?
By having posts for each beam line up over each other.
Why is it not advisable to interpolate between supported joist lengths?
Stretches building code’s design to it’s maximum.
List 5 factors that must be considered before beginning to lay out floor joists?
- Alignments of framing.2. Economical use of material.3. Location of plumbing fixture.4. Location of bearing walls and non bearing walls.5. Location of floor openings.
How is the support given to load bearing walls that are perpendicular to the floor joists?
If the bearing wall is perpendicular to the joists, the supported wall must be directly over the supporting wall or offset by no more than 3’ for ceiling loads and 2’ for floor loads.
How are load-bearing walls that are parallel to the floor joists supported?
If the wall is paralell to the floor joist, place directly under wall to transfer the load to a bearing wall beneath.
How are load non-load bearing walls that are paralell to the floor joists supported?
If non-bearing wall is paralell to the floor joists, support the wall with blocking between the joists at least every 1.2 m unless wall lands on the regular joists.
How are non load-bearing walls that are perpendicular to the floor joists supported?
Non bearing walls perpendicular to the floor joists do not have to be blocked or supported by extras
What is the maximum distance between rows of briding?
184 mm or 1 x 8.
Why should the manufacturer’s instructions be followed when installing an engineered floor system?
If the product was installed in a different manner tahan the testing, it would not be approved and it may cause failure.
Using figure 23, what are two products that can be used a rim board?
1 and 1/8 thick to rim board or 1 and a quarter thick timberstrand lumber (LSL)
Using figure 24, how much longer should squash blocks be compared to the I joist depth?
1/16”
Assuming a joist depth of 11 and 1/8, how close to a bearing can a 5” square hole be cut in a TJI 210 series?
3’0”
Can the flange be cut or notched?
No
How close to the flange can a hole be cut?
Up to 1/8 from the flange.
Where can a 1 and 1/2 hole be made?
Anywhere in the web outside hatched area shown.
Using figure 27, what must be done for the hangers
Web stiffener is added
Using figure 29, how much end bearing is required for I joists?
1 3/4
Using figure 28, how long are the nails for fastening an i joist to a top plate and how far in from the end of the joist mus tthe nails be placed?
3 and 1/2 and 1 1/2
What is the first step in the building of pony walls?
Lay out the sill plates. This includes the on-centers for the studs, locating openings and drilling holes for the anchor bolts.
How big should the hole you drill for a bolt in a sill plate be?
1/8” larger than the bolt diameter to allow the sill plate to be positioned accurately.
Once all the plates are in place, and bolts are in, what is the next step?
Check the building dimensions and check for the square and straightness of the sill plates. If everything checks out correctly, finish tightening the nuts.
What is the main difference between a regular wall and a pony wall?
The main difference is pony walls and regular wood-frames walls is that the bottom plate of pony walls is also the sill plate.
True or False, you must seal the joint between the bottom plate of the foundation wall with caulking?
Yes, to create an air barrier.
In crawlspace construction, what does an interior pony wall take replace?
It often takes the place of the beam to support the floor.
True or False, interior pony walls need sheathing?
False, code does not require it.
What should the foundation wall of an interior pony wall contain?
It should include a curb to keep the bottom plate at least 6” clear of the ground seal.
What is the purpose of a pony wall with interior support?
Since the pony wall will not deflect at all, this will create a stiffer floor.
What diameter hole should be drilled for an anchor bolt?
1 1/8 larger than bolt diameter
What are two factors that affect the size of pony wall studs?
- Load on the wall2. Unsupported lengths of the studs.
How tight should an anchor bolt be fastened?
Just snug, not over tightened.
What safety precautions should be taken when applying wood preservatives?
Eye protection, long sleeves, and gloves.
What is a string line used for when building pony walls on out-of-level foundation walls?
Determining stud lengths.
If an interior pony wall is not sheathed, what is required in lieu of sheathing?
Bracing on at least one side.
What kind of wood must be used when supporting heavily loaded beams at their top plate?
Douglas fir
What kind of foreces must an exterior column resist?
Uplift and lateral
What kind of forces must an interior column resist?
Only against lateral.
For light-duty applications, what would you use to provide uplift and lateral protection?
A post saddle.
Columns supporting floor loads are secured at the base with what?
A heavy duty anchor that allows the column to be bolted to the anchor
When must an engineer be involved with building on columns?
When the spacing of columns doesn’t exceed 3m (9’10”) oc. A registered professional engineer must design the size of columns and their foundations when the columns exceed this spacing or carry point loads.
What is the cantilevering principle?
“if a span is divided into four equal distances, each distance will create a “quarter points” Individual layers of the beam are allowed to cantilever over the post and join at or within 150 mm of, the quarter points near the post as long as they are continuous over the adjacent supports”
Three ways beams can be installed?
Framed into walls, supported on posts or supported on the concrete foundation.
Beams that are twice as high as they are wide are subject to what?
Roll-over, a guesset on both sides is needed in these cases.
How are steel beams fastened in place?
Drilling and bolting or welding to anchor plates cast into the concrete.
When framing a steel beam in flush framing, how much of a gap must be left above the steel beam to allow the wood joists to expand and contract due to moisture change?
1/2”
Why are footings for columns larger than footings for walls?
The load points imposed in the footing are greater and need to be spread over a greater area.
What is a pier?
To support a column.
When building up a beam, at which quarter points are the lamination joined?
The quarter points of the clear spans closest to the interior supports.
What is a flush beam?
A flush beam has the joists butting into it for floors. The beam is flush to the tops of the floor joists. In a ceiling, the beam is flush to the underside of the ceiling joists.
What is a common joist?
The common joist are full length spanning floor joists. These joists are supported by sill plates, walls, and beams.
Minimum end bearing for floor joists is?
38 mm or 1 1/2”
What kind of nail must be used for ends of floor joists?
2 x 3 1/4”
Solid blocking and briding are spaced at what distances?
No further apart than 7’ 0” o.c
Strapping and blocking must be nailed at what distance?
No further than 7’ 0 “
Should you nail the bottom ends or leave them loose when the floor joists are still wet?
Wait for them to dry, nail just before the ceiling finish is installed.
How should panel-type floor sheathing be spaced on the outside edge and along the middle?
6” oc on the outside edges and 12” oc in the middle sheet
BC code requires screws and ring nails to be what length?
1 3/4” and atleast 2” long
When are trimmer joists around floor openings required to be doubled?
When the header joist exceeds 800 mm or 32” in length
What is the minimum end bearing for floor joists?
1 and a half
What is the minimum nailing for floor joists to sill plates?
Two 82 mm 3 1/4 toe nails.
Does the BC building code regulate how far overlapping joists extend beyond the edge of a beam?
No, but good practice is “not more than 12” or “no more than the joist depth”
How is a toilet located in the space provided for it?
Centred in the space and 12” from behind the finished back wall.
List the order of installation of the floor joists around a floor opening?
1) Inside trimmers 2) Outside headers 3) Tail joists 4) inside headers 5) outside trimmers
How far is a 2 by 8 joist allowed to cantilever beyond its support if its supporting a roof load?
16 inches
How far is a 2 x 10 joist allowed to cantilever beyond its support if its supporting the floor load?
600 mm or 24 “
What part of an engineered floor truss can be cut?
None
What is the maximum distance between rows of bridging
7 feet o.c.
What size nails are used for diagonal cross briding?
2” galvanized box nails.
Why is lumber floor sheathing installed at 45-degree angle to the floor joist??
To act as diagonal bracing and so the edges don’t line up w/ finished flooring edges
Where is the chalk line positioned to lay out the first row of plywood floor sheathing?
48 and a quarter from the longest building side
Which edge of the plywood or OSB is located at the chalk line?
Groove edge
Why should nails not be placed close to the groove?
The groove won’t collapse (IN T&G)
What is a common joist?
The common joist are full length spanning floor joists. These joists are supported by sill plates, walls, and beams.
In crawlspace construction, what does an interior pony wall take replace?
It often takes the place of the beam to support the floor.
What is the first step in the building of pony walls?
Lay out the sill plates. This includes the on-centers for the studs, locating openings and drilling holes for the anchor bolts.
