Glencoe: Section 64 Flashcards
What do carpenters do that will reduce the chance that a nail will split the wood when nailing close to the end of a board?
blunt the tip slightly by tapping it with a hammer
What does using too many nails on wood do?
Actually weakens the wood and eventually causes it to split
Why were metal framing connectors developed.
At one time, all wood-to-wood connections were secured by nails alone. This resulted in varying strength of connections due to the skills of the carpenters. So metal framing connectors were developed.
Framing Connector
a metal framing connector is a formed metal bracket that is installed at framing connections using nails.
What are framing connectors often used for
to installed engineered lumber.
Also used where extreme conditions like high winds are expected.
What carpentry component is difficult or impossible to secure without the use of framing connectors?
I-joists
Tie
A type of metal connector tie.
For example a hurricane tie ties the wall framing to the roof framing.
A metal framing connector not only makes wood to wood junctions stronger but it makes
wood to masonry and wood to concrete connections stronger as well.
Are framing connectors meant to be seen?
Some ornamental connectors are but most will never be seen.
What material are framing connectors made from?
various gauges of galvanized steel
How are metal framing connectors made
formed into specific shape.
Galvanized. (deposits a layer of zinc on all sides to slow corrosion)
Standard metal framing connector galvanization coating:
G 60 or 0.005” thick zinc.
What nails should be used for metal framing connectors and why
stainless steel otherwise they would rust.
The best source about a metal connector is
the manufacturer. Also be aware of code
How far inland does salt spray effect metal
3000’
Most common metal framing connector
joist hanger
Joist hanger:
secures a joist to an intersecting framing member
Where are joist hangers used
where floor or ceiling joists meet another framing member such as a beam.
Standard joist hangers are made from X
and are intended for use with Y
18-gauge galvanized metal and
are intended for use with solid lumber joists
What nails are standard hanger joists installed with
10d common nails however always follow the manufacturers recommendations.
Special joist-hanger nails may be supplied
How do you install a joist hanger:
first, nail it to a beam.
Then slip the joist into the hanger.
Finally, hammer nails through the holes in the hanger and into the joist.
What happens if the sides of the joist hanger are spread too wide?
The joist will be raised slightly.
This causes a lump in floor sheathing
If the seat of the metal hanger is “kicked out” from the beam, settling later on may
cause the floor to squeak.
Most common mistake when installing joist hangers is
to use too few nails
To ensure that the tops of all floor joists are in exactly the same plane, a joist hanger can
be nailed to the end of each joist first. Hold the joist in the desired position then secure the hanger to the beam.
Joist hanger connection depends on nails for
shear strength
The wide variety of metal connectors makes them useful from
foundation to roof
metal post bases can be embedded in
concrete slabs or piers.
What do metal post bases embedded in concrete or piers do?
holds the wood slightly above the level of concrete to reduce the possibility of rot.
Various types of metal clips and brackets can be used to tie rafters and trusses to
a top plate
Metal connectors such as X are required in areas affected by earthquakes or severe weather
various types of metal clips and brackets used to tie rafters and trusses to top plates.
Most structural framing connectors are used in situations where the nails that fasten them are exposed to
shear stresses.
Why should dry wall screws never be used on metal framing connectors
they do not have the shear strength that nails do
Where can you find the nail schedule for metal framing connectors
the manufacturers instructions
When 16d nails are specified in metal framing connector instructions, this refers to
common nails, not sinkers
Sinker
nails that are slightly thinner and shorter than common nails.
Some manufacturers provide what with their joist-hanger
special joist hanger nails called joist-hanger nails. Their larger diameter improves their strength
Pneumatic nailers can be used to fasten
metal framing connectors into place
What is one danger of using pneumatic nailer on metal framing connector
piercing the metal and weakening it
What pneumatic tool is used specifically for nailing framing connectors
hardware framing nailers. A metal probe in the nose locates the connector hole and guides the nail
Some framing connectors use X holes for increased strength
angled holes
When building a single-level house on a concrete slab, the slab itself serves
as the floor system
If a house is not single level on a concrete slab, (i.e. it has basement or crawlspace) the floor system is
assembled from various types of wood framing and panel products
Floor framing for homes with basements or crawlspaces consists of
posts, girders, sill plates, joists or trusses, and subflooring.
In first floor framing, joists rest on
sill plates or girders or be attached to them
in second floor framing, joists rest on
a double top plate
Once sheathed, the floor joists
distributes load to the foundation walls for a solid base to walk on
Positive placement nails
Tip of the nail already sticking out. You know where its coming out.
What is generally used for floor framing
Nominal 2” lumber or laminated-veneer lumber I-Joists
In floor framing, floor trusses can be used as either
griders or as floor trusses
What advantages does engineered materials offer in floor framing
light weight, consistent strength, long spans
In the average house, the distance between opposite foundation walls is too great for
a single floor joist to span
Floor joist
any light beam that supports a floor
How do you overcome the fact that on the average house the distance between opposite foundation walls is too great for a single joist to span
a pair of joists are used to span the distance.
How are a pair of joists spanning the foundation walls supported
the outer ends are supported by the foundation walls, whereas the inner ends are supported by a grider
Girder
large principal horizontal member used to support floor joists.
The ends of a girder supporting the floor joists are supported by
the foundation walls
Post
is a wood or steel vertical member that provides intermediate support for a girder.
Girders and posts can be made out of
Posts are sometimes made out of
solid lumber, engineered lumber, or steel
concrete or brick
Posts are often used in
basements beneath the main girder. They may also be used in a garage to support ceiling girders.
Posts are often spaced
8’ to 10’ OC
the exact space depends on the size of the load
A wood post must be X and at least X x X and is usually Y x Y
solid
4x4
6x6.
A wooden posts ends must be
flat and securely fastened
Because a wooden post transfer weight to a fairly small area of the foundation
the slab portion directly beneath the post must be thickened
Thickened slab
thickened part of the concrete slab to support the weight of the load transferred by the post.
Sometimes a post is raised by a
heavy-gauge metal bracket
Why are Lally columns preferred in residential?
often preferred in residential construction because they are strong, easy to handle and take less space than solid wood posts.
Lally columns
steel posts with flanges. The top flange is bolted to the grider, The bottom flange is bolted to the concrete pedestal.
Steel posts must be at least
3” in diameter to protect against rust.
Steel posts are sometimes X to increase strength
filled with concrete
Girders are generally placed X
halfway between the longest foundation walls and parallel to them.
Pros and cons of steel vs wood girder
steel does not shrink but is heavier
Wood shrinks but is easier to connect floor joists to wood girders.
Floor joists often rest on top of X
This method Y
a girder
reduces head room
Sill plate
horizontal framing member anchored to the foundation wall
If the floor joists rests atop the girder, the girder must be
at the same level as the sill plate.
Two methods of resting floor joists:
Method 1: floor joists rest on top of girder
Method 2: floor joist is nailed to girder with joist hangers which makes the tops flush
Wood girders are available in several forms:
Solid wood girders
LVL girders
Glulam
Why are solid wood girders no longer widely used
solid wood of suitable size and quality is no longer readily available.
Built up girder:
Used in replacement of solid wood girder.
Built on site. Consist of three to four pieces of solid number nailed face to face.
To make a built up girder:
Facenail each layer with 10d nails as follows:
stagger the nails 32” OC at top and bottom
Nail two or three times at the ends of every board including splices
Stagger the joists.
How do you determine a steel girders strength:
the depth of the web and the thickness of the beam’s steel. Not the size of the flanges.
Face nailing:
a nail is driven straight through the thickness of the lumber and into another piece.
Toe nailing:
a nail is driven at an angle from the face through the edge of the lumber and into another piece.
Why does toe nailing call for smaller nails than face nailing
long toe nails increases risk of splitting wood
Steel girders come in two different shapes:
I beam with web larger than flanges
W-beam called wide flange. Web and flanges are the same width
Steel beams are ordered based on two criteria:
Height and weight
How do you measure height in a steel beam?
Flange to flange
How do you measure weight of a steel beam?
weight of a one-foot length of the beam
Steel beam:
W12 x 45#
What does that mean?
Wide flange (W) 12” wide. and 45lbs per foot.
On steel beam notation what does an S stand for
I-beam
If a steel I-beam is to be used as a girder, what must be attached to the top of the beam?
wood bearing plate.
What does a wood bearing plate attached to the top of a steel beam do?
allows you to toenail the floor joists to the beam.
How are wood bearing plates fastened to steel?
steel pins driven by a powder actuated tool
Load:
an explosive gunpowder charge drives hardened steel pins into steel or concrete.
Alternative to steel pins driven into the I-Beam
Steel fabricator can weld short lengths of threaded steel rod to the top of girder which wood plate can then be drilled to match and secured with nuts and washer.
Beam pocket:
notch in the foundation wall which girders fit into
Floor truss can also be used as
a girder
trusses are made in
the factory to the specification of the job
Floor trusses can be used in place of lumber joists where
long spans are required
Parts of a floor truss
chords, webs, and connector plates.
Floor truss web:
allows heating ducts, water lines, drain lines, and other items to be passed through with ease.
Most common type of floor truss in residential construciton:
parallel-chord floor truss. Top and bottom chords are parallel to each other over the length of the truss.
What must you do to floor trusses as they are being installed?
brace them. Truss fabricator can provide detailed bracing instructions
when are Posts and girders installed
after the foundation walls are complete and the forms have been stripped. In houses that have a basement, the basement floor slab may also be in place.
To located thickened slab points for post placement
sometimes metal anchors are placed when the slab is poured.
What if there are no anchor points to designate where posts should be placed?
consult the plans
Floor trusses should be braced temporarily with
2x4 stock until they are sheathed.
After posts are in place,
install the girder and brace it if necessary
How are steel or glulam girders placed?
crane or special forklift
How are wood or built up girders placed?
sometimes lifted into position
How much should the ends of the wood girders beat on the masonry walls in inches?
4”. This will reduce the risk of the crushing the wood fibers.
How much clearance on the sides of a girder into the beam pocket have?
1/2” on either side
This prevents wood from absorbing the moisture of the masonry
To determine the height of a wooden post:
Stretch a string line tightly across the foundation.
Measure from the floor to the line.
Calculate the length of the post based on deducting the depth of the girder. Be sure to account for the thickness of any other elements that will be attached to the post such has bearing plates.
To determine the height of a steel post:
the height of the floor to the bottom of the girder is all that is needed. Post should be centered on the girders width.
Solid lumber was once the only material used for joists but modern builders now use
LVL
The most common LVL product is
the I-Joist
Box sill:
a box sill consists of a sill plate (also called a midsill or just silll). and a rim (or band) joist. The sill plate is anchored to the foundation wall and the rim joist is toenailed to the sill plate.
What completes the floor system
floor joists and subflooring
Subflooring:
consists of engineered wood sheets such as plywood or oriented strand board overlayed on floor joists
Sill plate:
lowest member of the wood floor frame and provides a smooth bearing surface for the floor joists.
What is the sill plate made from:
2x4 or 2x6 preservative-treated lumber.
Preservative-treatment
protects wood against moisture damage and insect attack.
How are joists secured to the sill plate?
toe nailed or metal framing anchor if specified by code.
Why are sill plates important?
Sill plates establish the quality of all the framing that will follow. If they are not level or secure the entire floor system will not be level and the house may not survive an earthquake.
When are the anchor bolts for the sill plates installed?
when the foundation is placed.
Sill plates should be anchored to the foundation with at least
two 1/2” bolts in each plate.
According to the building code, the bolts must be spaced in the foundation for the sill plate no more than X’ OC and there must be a bolt within X” of each end of every plate.
6
12”
How do you prevent cold air from leaking into the house through the sill plate?
The plate should be set on top of a foam or fiberglass sill sealer.
Joists are usually placed X to girders on X” or Y” centers. However, check the house plans for the exact size, spacing and direction of the joists.
perpendicular
16” or 24”
Where should you install a termite shield to protect from termites traveling from foundation walls to wood members?
beneath the sill plate
Sill plates on opposite walls should be installed so that they are
parallel to each other
Installing sill plates:
Step 1:
Check to see that foundation is level and square. To check a simple rectangular foundation measure diagonally from corner to corner. To check a more complex foundation, use the 3-4-5 method for squaring walls. Adjust the plates as needed so they will be square.
Installing sill plates:
Step 2:
Establish the location of the sill plate. From the outside edge of the foundation wall, X. If the outside wall of the sheathing will be flush with the outside edge of the foundation wall, Y
measure back a distance equal to the width of the sill plate
measure back the width of the sill plate plus the thickness of the sheathing.
Installing sill plates:
Step 3:
Place sill plate stock around the foundation. Use only straight flat lumber that has been preservative-treated. Any wood placed against concrete should be preservative-treated to resist rot.
X
Place the edges of each piece against the foundation anchor bolts and mark the centerline of the bolts on the plate. Using a square, extend these marks across the width of the sill plate.
Installing sill plates:
Step 4:
Measure from the center of each bolt to the chalk line on the foundation. Measure the same distance on the plate, starting from the edge that is resting against the bolt. Mark the bolt centerline at this point.
Installing sill plates:
Step 5:
using a 5/8” spade bit, bore holes through the plate at each marked point. (if termite shields will be used, bore holes at the same locations in them using a suitable drill bit)
Installing sill plates:
Step 6:
Roll out sill sealer over the top of the foundation walls and press it into place. The weight of the buidling presses the sill sealer against the foundation wall to stop drafts.
Installing sill plates:
Step 7:
X.
Start at the high point of the foundation wall and check to see that the sill plate is level, using a builders level. An even more accurate technique would be to check the plate with Y. Shim beneath the sill plate with cement grout or with preservative-treated wood shims, as needed to make it level.
Slip the sill plate over the anchor bolts.
a laser level set up in a location that would allow you to check the entire foundation
Installing sill plates:
Step 8:
place a flat washer and a nut on each foundation bolt. Use a wrench to tighten each nut securely.
Joists are often nailed into place. However, X can be used to replace many of the nailed connections. The most common metal connector used in floor framing is the Y, shown being installed above.
metal connectors
joist hanger
What do joists hangers strengthen?
The connection between floor joists and the rim joists.
Joists are spaced X from one end of the house to the other, however, certain factors may interrupt this spacing, such as Y
Evenly
The need to provide a stairwell opening or extra room for plumbing drain lines.
When marking the joist layout, where do you begin the tape measure?
at the corner of the sill plate.
When marking the joist layout, make a mark X” from the outside edge of the sill plate. This will Y
15 1/4”.
Mark the location of the first joist.
When marking the joist layout, mark and X on the
side of the sill that the joist will rest.
After you have marked the first joist on the sill, mark every X” to indicate the positions of all the joists on that plate.
16”
When you have marked the location of all the joists on the sill plate, double check that a joist is centered every X’ because Y
4’ because this will ensure floor sheathing panels always fall along the centerline of a joist.
If the joists span the entire length of the foundation, what will the sill plate marking layout look like?
Identical
If the joists do not span the entire length of the foundation, what do you do to the joist layout on the opposite walls sill plate?
offset it by 1 1/2” (the thickness of a joist),
How much should joists overlap if they do not span the entire length of the foudnation?
3”
