Glencoe: Section 61 Flashcards
(167 cards)
1
Q
Lumber Defect:
A
Flaw that detracts from the quality of wood in either appearance of usefulness
2
Q
How many characteristics are considered when wood is graded?
A
25
3
Q
Warp:
A
any variation from a flat surface
It includes:
Bow, Crook, and Cup
4
Q
Carpenters can cut flawed 2x4 into
A
blocking
5
Q
The width and thickness of lumber given by two types of measurements:
A
Nominal and actual dimensions
6
Q
Nominal:
A
size of the board in inches as originally cut in width and thickness, not its length.
7
Q
After the board has been surfaced and seasoned at the mill, its X
A
actual dimensions become less than its nominal dimensions.
8
Q
Building codes use X dimensions
A
actual dimensions
9
Q
Dressed sizes apply:
A
after the wood has shrunk and been surfaced with a planning machine
10
Q
2x4 actually measured in dressed size:
A
1 1/2 x 3 1/2
11
Q
Why have sized of lumber been standardized?
A
Convenience in ordering and handling
12
Q
Softwood lumber is readily available in actual lengths of
A
8’, 10’, 12’, 14’ and 16’
13
Q
Common Nominal dimensions of softwood:
A
2”, 4”, 6”, 8”, 10”, 12” in width
1”, 2”, 4”, 6” in thickness
14
Q
Are hardwoods standardized for length or width
A
no
15
Q
Hardwood thicknesses:
A
1/4”, 1/2”, 1”, 1 1/4”, 1 1/2”, 2”, 2 1/2”, 3”, 4”
16
Q
2x4 is actually
2x10 is actually
once you get into 2 x 8 you
A
1 1/2 x 3 1/2
1 1/2 x 9 1/4
drop to a quarter
17
Q
The united states is the only lumber producing country that does not
A
use metric system.
18
Q
Wood imported using metric have these dimensions
A
thickness and width in MM
length in meters
19
Q
Wane:
A
– The presence of bark, or the lack of wood from any cause, on the edge or corner of a piece of lumber.
20
Q
Bow:
A
A flatwise deviation (bend) along the grain from a straight true surface. Bow is measured at the point of greatest deviation.
21
Q
Crook:
A
an edgewise deviation (bend) from a straight, true surface. rook is measured at the point of greatest deviation.
22
Q
Cup:
A
flatwise deviation (deviation) across the grain from a straight true surface, cup is measured at the point of greatest deviation.
23
Q
Check:
A
Small crack that runs across the growth rings. Occurs as result of seasoning
24
Q
Shake
A
lengthwise grain separation through or between growth rings. May be further classified as ring shake or pitch shake
25
Split:
Lengthwise separation extending from one surface through the piece of lumber to the opposite side or an adjoining piece
26
Decay:
Disintegration of wood due to the action of wood destroying fungi (dot, rot, unsound wood)
27
Knot
Place where branch once grew. Classified according to size, quality, and occurrence. Measured by averages.
28
Knothole
left by the removal of an embedded knot
29
pitch
accumulation of resin in the wood cells
30
Stain
discoloration on or in lumber other than its natural color
31
Torn grain
torn spots created as the broad is machined to size
32
Decay and damage by insects to wood is most likely to occur when:
wood is wet
33
A house must be designed to encourage rain water to
drain away
34
Water vapor is given off when
cooking, washing or other household activities
35
Water vapor can do what to a house
pass through walls, ceilings, when it reaches a cold surface it forms water droplets.
36
Sources of water in homes:
rain, water activities in homes, leaking pipes.
37
What can allow water into homes:
gaps in exterior wood trim or between a chimney and siding
38
Wood will not rot if
it is kept dry
39
Fungi needs:
air, warmth, food (wood), moisture
40
Dry rot
An advanced type of decay where wood is Brown and crumbly. Wood may also be white and spongy
41
Decay wood is often indicated by
sunken areas on surface or a hollow sound when wood is tapped with hammer.
42
Fungi can grow on surface of wood if
air around is very damp
43
Fungi grow most rapidly between
70f and 85f
44
Moisture content of X or less is generally dry enough to stop fungi
20% or less
45
When untreated, sap wood of all common native woods
have low resistance to decay
46
Natural decay resistance of native woods lies in the
heartwood
47
Of the commonly used species in household construction, which wood has high resistance to decay
Bald cypress, redwood, and various cedars
48
Why is heartwood becoming harder and harder to obtain
increasing amounts of timber are cut from the smaller trees of second growth stands in which little heartwood has developed.
49
When decay resistant woods is needed
Preserve treated wood is used
50
Insects that damage wood:
termites, carpenter ants, and beetles
51
Termites:
termites are the most destructive of the insects that infest wood.
52
Best way to protect against termites:
during planning and construction: remove all woods debris such as stumps and lumber scraps from the soil before and after construction. Also NO WOOD MEMBERS SHOULD BE IN CONTACT WITH SOIL
53
Forms of termite protection:
chemical termiticide, physical barriers and treated wood
54
Two types of termites:
Subterranean and dry-wood
55
Subterranean termites:
account for 95 percent of termite damage. They eat the interior of wood and cause most damage before they are detected. They effect Hawaii and southern 2/3 of united states. They thrive in moist warm soil containing food. They build shelter tubes over foundation walls and pipes about 1/4 to 1/2 inch.
56
Two types of termite blocking methods:
Metal shields 12" min above ground, and covered soil.
57
Most destructive termite:
Formosan termite
58
Dry wood termites:
Fly directly to the wood instead of building tunnels from the ground. Less destructive
59
Carpenter ants:
Northeast, northwest, midwest.
Nest in ground as well as dead trees, firewood, and houses. Do not eat wood but plant juices, insects honey and food particles.
60
How do carpenter ants damage wood:
irregular tunnels they create for their nests.
61
What indicates a carpenter ants presence
small sawdust particles.
62
Control for carpenter ants:
chemicals
63
Two types of beetles that cause damage to wood:
powderpost and deathwatch
64
Powderpost:
Enter house via already infested wood, only attack hardwood
65
Deathwatch:
eats both soft and hard wood
66
Carpenter bees:
cut 1/2" diameter hole in bare or untreated wood. Build nests by boring tunnels.
67
Lumber can be treated with:
Liquid wood preservatives soon after being milled
68
Wood preservative:
a chemical that protects wood
69
Most common treated wood
Fir, spruce, and pine generally used outdoors or where in contact with concrete or masonry
70
Ways of preservative treating wood
Injection, dipping and drying, chemicals forced into wood under pressure
71
Preservative treated wood is:
graded and stamped to indicated its suitability for various uses
72
Preservative can accelerate
metal corrosion, so special fasteners may be needed.
73
Fire retardant treated wood
do not stop wood from burning but can limit the amount the fire spreads.
74
Moisture content of fire retardant treated wood
lumber is dried to 19%
| plywood dried to 15% or less.
75
Can i modify fire retardant treated wood?
yes. It can be cut to length, drilled and lightly sanded. However ripping and surfacing and milling operations are only permitted in certain cases.
76
Today, both types of these woods are used in construction:
Solid wood and engineered wood.
77
Engineered panel:
any manufactured sheet product, including plywood, which is made of wood or wood pieces bonded with a natural or synthetic adhesive.
78
Plywood
a building material that consists of layers of wood veneer and sometimes other materials that have been glued together.
Light but strong.
79
Unlike solid lumber, plywood comes in
large sheets called panels that can be installed quickly
80
Other popular panel products other than plywood are made out of
wood flakes, dust, or fibers mixed with adhesives or Portland cement.
81
All manufactured panels including plywood share these characteristics:
Engineered for the efficient use of wood resources.
Manufactured using various natural or synthetic adhesives.
Performance is predictable.
82
Uses of plywood:
Made into foundation forms providing stiff uniform surface for concrete
Plywood floor wall and roof sheathing stiffens and strengthens structure of house.
Smooth easy to paint surface
Underlayment, plywood makes a strong smooth substrate for finish flooring
Cabinets and built ins are made of it because it host fasteners well and accommodates various types of joinery.
83
Types of plywood:
Structural plywood and hardwood
84
Structural plywood:
Used where strength is more imporatant than looks, sheathing and subflooring and concrete forms.
85
Hardwood plywood:
Used for paneling, cabinets, and other interior features
86
Plywood consists of layers of
wood veneer and sometimes other materials that have been glued together.
87
Wood veneer:
very thin, pliable sheet of wood that has been sawed, peeled, or sliced from a log.
88
Plies:
when wood veneer sheets are used in ply wood.
89
Plywood is manufactured with X number of layers that:
odd number of plies layers that run at 90 degree angle from neighboring layers. May have 3 5 or 7 layers. Grains of outmost layers runs in same direction.
90
Face Ply and Core Ply
Face plies are the two outer ply layers. Core ply are inner.
| The best quality face ply is called the front, the lesser quality is caleld the back.
91
Plies that are arranged at 90deg angles are called
crossbands.
92
Lumbercore plywood
Veneers bonded to a core of glued up lumber or particle core
93
Hardwood ply may be made entirely out of
veneers
94
How Plywood is Manufactured:
| After a tree is cut it:
is trucked to the plywood mill and stored into a pond.
95
Only select logs qualify as
peeler logs
96
How Plywood is Manufactured:
| Chosen log is lifted from pond and
cut to length
97
How Plywood is Manufactured:
| As log cut to length moves to the mill it is
debarked by high pressure jets
98
How Plywood is Manufactured:
| After debarked
log is lifted into a lathe which slices continuous strips of veneer from the log.
99
How Plywood is Manufactured:
| After veneering
it moves to clipping machine where giant knives cut into a specific width
100
How Plywood is Manufactured:
| After clipping
Sent to the dryer to reduce moisture
101
How Plywood is Manufactured:
| After dryer
natural defects in the veneer sheets are cut out and holes are patched with solid wood or synthetic patching material. Some sheets then go to the glue spreader where large rollers cover both sides with adhesives.
102
How Plywood is Manufactured:
| After natural defects are removed and some are glued
Glued and unglued sheets and stacked alternatively together to make the desired thickness. This is called the Lay Up process
103
How Plywood is Manufactured:
| After Lay Up
Panels are bonded together using pressure and sometimes heat. The panels are trimmed to exact length and thickness and blemishes are repaired. They are then graded.
104
How plywood is graded:
grade marks are stamped on the back face of plywood. Grade identify all features of panel.
105
Two methods of grading plywood:
Prescriptive and Performance
106
Prescriptive plywood grading:
panel is graded by the quality of its veneer, adhesive used to assemble it, number of layers(plies) and dimensions.
107
Performance plywood grading:
panel is rated according to its suitability for a particular use. Like moisture resistance.
108
Hardwood plywoods are graded primarily by
veneer quality, species, and arrangement of face plies.
109
In prescriptive grading, wood species are divided into five groups based on
strength.
110
In prescriptive grading, describe how to veneer grade is printed
"A - B" format.
| Front face - back face grade.
111
Panel made with rater resistant adhesive is followed by an
X
112
Elements of a plywood grade stamp
```
Grade of veneer front and back panel
Species group
Type (interior exterior)
Type of glue
Product standard governing manufacturer
mill number
sometimes application (siding) and identification index.
```
113
Composite Panel Product:
made from pieces of wood in a variety of forms, including veneer, chips, and fibers. The wood is mixed with adhesives and formed into panels. Share many of the same characteristics as plywood.
114
Most common types of Composite Panel Product
Oriented-strand board (OSB), hardboard, medium-density fiberboard. (MDF), and particleboard.
115
Chipboard, waferboard, flakeboard
all names for panels that are essentially the same or similiar to OSB
116
Com-ply
panel developed by APA (The Engineered Wood Association). Compressed wood strands core with veneer wood faces.
117
Eco advantage of composite panels?
Made from otherwise useless wood. Small trees or unsound wood.
118
Two strong influences on the properties of composite panels are
The size and shape or individual flakes and particles.
| The ratio of adhesive to particles.
119
Most adhesives in composite panels are
water proof such as Urea-formaldehyde. Trend toward developing other adhesives because of health concerns towards off gassing.
120
Why is wax(0.5% to 1%) added to panels?
| What else is added sometimes
to reduce moisture absorption and make it suitable for sheathing.
Fire retardant chemicles
121
Difference between ply-wood and composite panels?
The way the wood is processed.
In composite, logs or woodscraps are processed mechanically to create small unform pieces. Mixed with adhesive then squeezed under pressure to create sheets.
Then finished or treated.
122
Most common panel size:
4' x 8' but panels go up to 8 ' x 16'
123
Concerns about using future composites
Each new product adds chemicals not found in solid wood. Therefore consider the health and environmental effects. And review the material safety data sheet.
124
composite panels are free from
cracks and other imperfections found in solid or veneered wood.
125
Use blades with X when cutting composite panels
carbide
126
The absence of voids gives composites X
full uniform contact surface for gluing.
127
OSB
oriented strand board is made from wood strands bonded with adhesive under heat and pressure.
Strands in each layer run more or less in the same direction and then layers are placed perpendicular to each other. 3 to 5 layers usually.
128
OSB is available with X grove edges.
square or tongue and groove edges.
129
Thickness of OSB
3/8" to 1 1/8"
130
OSB are not suited for
long term exposure to weather.
131
To increase moisture resistance what is done to OSB
edges are coated at the factory with sealant.
132
Which is most likely to swell or shrink in response to humidity, OSB or Plywood:
OSB
133
OSB sheathing and subflooring should be installed with a X gap between the ends of adjacent panels and Y at the sides.
1/8"
| 1/4"
134
What happens if the edge seal of OSB panel is damaged.
Moisture can wick into the panel and swell the edges.
135
How should OSB panels be stores on the jobsite
off the ground stacked and supported by 4x4 stringers or other blocking. Covered loosely so as not to trap moisture. Steel binding that secures panels during delivery should be cut right away to stop damage if swelling
136
Fiberboard
logs are chipped into small pieces of wood that are then reduced to fibers by steam or mechanical processes. Fibers are refined and mixed with an adhesive and compressed.
137
Fiberboard generally includes panel products such as
hardboard and medium density fiberboards
138
Hardboard:
high density fiberboard.
Slurry (mixture of fibers and water) is formed into a mat. Mat is compressed under several stages of pressure to form the final panel
139
Hardboard is available in what grades?
Standard and tempered.
Standard is given no additional treatment
tempered is given linseed oil or tung oil prior to pressing to increase stiffness and water resistance.
140
S1S and S2S
hardboard with 1 side smooth
| hardboard with 2 sides smooth
141
Hardboard available thicknesses
1/8" and 3/8"
142
Standard Hardboard panel sizes
4' x 8' but up to 6' x 16'
143
Perforated Hardboard
closely spaced holes drilled or punched into it.
144
hardboard can be printed to X
match grains of oak and walnut or other woods
145
Medium-density fiberboard
uniform compressed wood fibers mixed ueraformaldehyde adhesive. Smooth surface. Manufactured similar to particleboard.
146
Why should protection when working cutting or sanding composite products
fine dust
147
Particle board
combining wood particles or flakes with adhesives and hot-pressing them into panels. Particles near top and bottom are fine and coarser ones are located near core.
148
Is particle board weaker or stronger than OSB
weaker
149
Where is particle board used?
indoor wherever smooth and inexpensive material is needed.
150
Particle board standard sizes
1/4" to 1 1/2" thick and from 3' to 8' wide and up to 24' length
151
How many different grades of Particle board are there?
| How many densities?
ten.
| three (high, medium, and low)
152
Fiber-cement Board
Cellulose fibers are bound together with a mixture of Portland cement, ground sand, additives and water.
153
Benefits of fiber-cement board
non-combustible and rot proof.
154
Fiber-cement board standard sizes
5/16' thick.
Comes in sheets of 4'wide and 8',9',10', or 12' long.
One side is rough, other is smooth.
155
What board is desirable for siding?
Fiber-cement board because its smooth finish and stability.
156
Fiber cementboard should be stored
level dry surface. Keep corners from being struck.
| Carry panel on edge by two people.
157
Breathing excessive amounts of silica dust can lead to
Silicosis
158
Engineered lumber
any manufactured product made of solid wood, wood veneer, wood pieces, or wood fibers in which components have been bound together with adhesives.
159
Pros of Engineered lumber products
Stiff, strong, dependable, and versitile.
* Uses wood that would have otherwise been waste
* Predictable performance
* Available in wide variety of dimensions
* Free of defects found in regular lumber
160
Engineer lumber products include:
```
Laminated-veneer header and I-joists
Glue-laminated beams
Finger-jointed studs
Laminated-strand lumber posts
Oriented-strand lumber window framing stock
```
161
Where should engineered lumber not be used
where it will be permanently exposed to weather. Should not be in direct contact with concrete or masonry.
162
LVL
laminated veneer lumber is a family of lumber products made with wood veneer as the basic element. Lightweight, rigid and available up to 66'
163
How is LVL made
Layers of veneer are glued together in various ways.
164
How is LVL different from plywood
LVL is used for beams and headers and joists instead of panels.
LVL has parallel lamination so each layer runs in the same direction as opposed to ply woods perpendicular lamination
165
How are LVL products made:
Sheets of veneer are moved through drying ovens, till moisture content is 8%. It is checked and graded
Goes to glue spreader. Top is coated.
Highest grade veneers are placed on top and bottom of stack.
Pressure and heat applied to cure adhesive. Final material is called a billet, which may be up to 80' long.
166
Finished LVL products are typically shipped to dealer in X' increments
60'
167
Dealer of LVL cuts the LVL in X' increments
2'
