Wood biology and potential production deterrents Flashcards
0
Q
Why have engineering building products been developed
A
They use waste that accompanies sawn lumber production and some of these products such as beams are not only stronger than solid lumber but are available in sizes wider and longer than the lengths cut from a single log
1
Q
Name some engineered building products
A
Particleboard waferboard, dense fiberboard, laminated veneer beams, glue laminated beams,parallel strand beams and plywood
2
Q
Name nine species Of wood that are readily available
A
Douglas fir, western larch, western, hemlock, Pacific Coast cypress, eastern larch, jack pine, lodgepole pine, sitka spruce and western red cedar
3
Q
what is sawn lumber
A
Lumber that is cut from logs
4
Q
Is wood corrosive
A
wood is neutral it will not react with corrosive materials such as acids and alkali but it is susceptible to rot and must be protected with chemicals or by keeping dry and well ventilated
5
Q
what kinds of finish and paint can you use on wood?
A
It holds very well if it is dry. it is easy to paint, stain and varnish.
both oil base and latex based paint can be used on wood
6
Q
What are some disadvantages of using Wood
A
- It swells and shrinks when the moisture content in the atmosphere changes.
- it is likely to rot or be invaded by insects
- flammable
- it is not uniform in composition ex: has knots and different speeds of growth affect its strength
7
Q
What is the density of wood
A
500 to 600 kg/m³
8
Q
What is the density of steel
A
8000 kilograms per meter cubed
9
Q
What is the density of concrete
A
2400 kg/m³
10
Q
How long does it take for wood to mature to a size size that it can be harvested
A
From 40 to 100 years
11
Q
How can a wood beam and the supporting a bent steel beam after a fire
A
It burns slower than hot metal weakens
12
Q
List the three main parts of the tree
A
The crown the trunk and the roots
13
Q
This structure of the tree is an extremely thin region of living cells which is responsible for the formation of millions of new cells produced by a tree each year. the cells produced by this structure form other structures which make up the bulk of the tree
A
Cambium layer
14
Q
This region of the tree consists of light-colored commercially valuable wood . its function is to conduct sap upward from the roots to the crown of the tree
A
Sapwood
15
Q
This structure of the tree consisting of dark-colored structurally weak material is located at the center of the tree. first wood growth takes place around it
A
Pith
16
Q
These long narrow structures appear as fine lines on the surface of the cross-section of a tree trunk or branch their purpose is to conduct food and moisture laterally across the trunk or branches
A
RAYS
17
Q
This corky material is composed entirely of dead cells it’s function is to protect the tree from pests disease and damage
A
outer bark
18
Q
This part of Treewood is darker than other wood structures. Composed of dead cells with natural Tannins and resins it is more durable and less susceptible to decay then other wood structures. its main function is to give the tree structural support
A
Heart wood
19
Q
This region of the tree transports food manufactured in the leaves to other parts of the tree
A
Inner bark
20
Q
These structures consist of concentric circles or rings which are visible on a cross-sectional cut of the tree trunk or branch. they can be used to determine the age of the tree and eventually they form the woodgrain pattern when a log is sawn into boards
A
annular rings
21
Q
Which two different types of wood form annual growth rings
A
Springwood and Summerwood
22
Q
Why do tropical woods have an obscure grain while North American woods tend to have an obvious grain
A
North American winters and summers are very extreme in their conditions well tropical ones are less so and that affects the growth
23
Q
The sapwood region of softwood trees contains specialized cells which move sap through tiny openings called pits. what are they called?
A
Tracheids
24
What is water in a cell wall called
Bound water
25
When does wood shrink
When it dries
26
Where does the greatest shrinkage take place in a piece of wood
In it's width and thickness
27
Quartersawn wood is also known as ......grain
Edgegrain
28
When is a cup formed
When an edge grain board or a quartersawn board dries out
29
Which is the heaviest species of softwood
Western Larch
30
Which is the latest species of softwood
Western red Cedar/Spruce/pine/fir
31
Which species of wood is considered to be the strongest of the softwoods
Douglas fir /Western larch
32
Which species of wood is considered to be free from resins
Western hemlock
33
Which species of wood is best suited for manufacturing ladders
Sitka Spruce
34
Name four species of woods that have very little or no taste or odour
Basswood, Alpine fir, Western larch ,sitka Spruce
35
What is Pacific Coast yellow cedar noted for
It's resistance to acids and DEcay
36
Which species of wood has a deep warm brown color
Western red Cedar
37
Name the two species of Spruce that are found in Western Canada
Coast sitka spruce, English man Spruce
38
Where in Canada are Jackpine and Balsam fir Found
Eastern Canada
39
What is compression wood
Dodd
40
What is compression wood
Abnormal wood that forms on the underside of leaning and crooked coniferous trees. it is characterized by hardness,brittleness, and a relatively lifeless appearance. It's color is easily distinguished from that of normal wood. Lumber with this defect is not permitted if the defect can be readily seen, or if it rates potentially damaging in the stress grades, or if it is specifically listed as unacceptable
41
What are three common causes of mechanical defects in lumber
Improper seasoning techniques, improper handling and improper storage
42
What is a split in a board
Separation of wood which happens when wood cells Tear apart
43
What is a check
A lengthwise separation of wood which usually occurs between or through the rings of annual growth
44
What is the pith shake
It is also known as a heart-shake, star shake, or heart check it extends through the growth rings from or through the path towards the surface of the piece. it can be distinguished from the season check by the fact that the greatest width of the season check in the pith- centered piece is farthest from the pith
45
What is a ring shake or cup shake
The split which occurs between the growth rings and partially or wholly in circles the pith
46
What is a sound knot or live not
It is formed from a live branch. It starts out as a bud on the side of the treetrunk and as it develops successive layers of wood cover it. As a result both trunk and branch increasing girth at roughly the same rate as long as the branch remains alive it's outer growth rings remain fused to the adjoining Trunk. and even after the tree is cut into planks the knot can be depended on to remain in place
47
What is a dead knot or. Black knot
It's forms after the branch dies this often happens in lower branches that been deprived of light by too dense foliage above them. Without light food to the branch of diminishes, and the branches die and eventually drop off. The tree continues to grow and eventually envelops the stump of the dead branch. When this is cut into a board it is called a tight knot which is actually separate in the board and cannot be dependent on for strength
48
What is the difference between a loose knot and a tight knot
A loose knot is a dead not which has completely come loose and there is a hole in the board a tight knot is still the separate piece of dead branch still in the board.
49
In which application wood a knot be considered an asset
When it is in Knotty Pinewall paneling where knots lend a decorative quality to the final product
50
What is Wane
Wane is bark that has been left on the edge or corner of a piece of lumber;or it is missing wood on the edge or corner, arising from any cause
51
What is pitch
The accumulation of resinous material. it usually collects when wood in the tree is damaged by wind or lightning
52
All the Decay results from the invasion of a single class of plants called what
Fungi
53
The moisture content is below this percentage for no further rot to occur.
20
54
What is sap stain fungus
It turns the wood blue but has no effect on the structural strength because it feeds on the contents of the wood cells without damaging the walls
55
What is Rot fungus
It feeds on both the contents of the cells and the cell walls themselves and breaks large holes in the cell walls and holes cause the wood to deteriorate.
56
What are three kinds of rot fungi
brown rot
white rot
dry rot
57
How do you get rid of rot fungi
Discard the wood or have the infected portions removed
58
What is brown rot
It attacks the cellulose material that makes up the walls of oneself, and eventually it reduces the affected wood to brittle, brownish material.
59
What is white rot
It attacks both the cellulose that makes up the cell walls and the lignin that binds the cells. white rot is also called white spec, which is an initial stage of White rot. Infection shows itself as a soft, pulpy mass of white., Which has no structural strength. Like most forms of brown rot, Whitrock develops before tree is felled and does not persist after drying. Amputate
60
What is dry rot
It survives the drying process
It occurs in wood surfaces that are in contact with damp walls
The name dry rot arises from the condition which infected what is reduced. The wood breaks into dry brown cubes, which crumble to fine dust under finger pressure.
61
How do you prevent decay
Ensure that lumber has been dried to moisture content of 20% or less
space ensure that wood placed in service is adequately ventilated
treat wood with preservatives to prevent fungus attack
62
What are four insects that damage wood
Carpenter ants
western subterranean termites
Pacific dampwood termites
Powder-post beetles
63
How do you know carpenter and is living in your building
Sightings of worker ants which are 6 mm to 12 mm in size
House of sawdust
Rustling sounds in walls, floor or ceiling
Sightings of workers inside the house in winter or spring when it is too cold for them to be outside
Ant trails to and from the house
64
How you know Western subterranean termites are in your building
Western subterranean Termites live in wood in contact with the soil but will travel inside specially-constructed mud tubes to feed on wood above the soil. Most of the damage is confined to wood in basements and at ground level
They are winged termites and are about 10 mm long and have black bodies and long pale wings
65
What is Pacific damp wood termite
Attacks wood with a high moisture content. In some cases., The entire inside of infested wood is eaten leaving only the other shell
Male and female template terminates have brown bodies with long, translucent, brown wings. Their overall length is about 25 mm. They usually leave the colony in large numbers during late summer. the worker termite is creamy white in color and never leaves the wood
66
What is a powder post beetlew
The bore round holes 2 to 3 mm in diameter inside the wood. their tunnels are filled with sawdust and excrement. Sapwood with a high moisture content in shaded areas is especially susceptible to attack.
67
What is chipped grain
Particles of wood that are chipped or broken below the line of cut. They are too small to classify as torn grain.
68
What is torn grain
An irregularity in the surface of a piece, where wood has been torn or broken out by surfacing.
69
What is raised grain
And unevenness between the Springwood and Summerwood on the surface of dressed lumber
70
What is loosened grain
Grain separation or loosening, without displacement, between Springwood and Summerwood
71
What is Skip
An area that has not been surfaced cleanly
72
What is hit and miss
A series of skips, with surfaced areas in between.
73
What is mismatch
And an even fit in that results when adjoining pieces of worked Lumber do not meet tightly at all points of contact, or when the surfaces of the adjoining pieces are not in the same plane.
74
What is machine burn
The darkening of wood due to machine knives or rollers becoming overheated when pieces are stopped in the machine
75
What is machine gouge
A groove cut by the machine below the desired line
76
What is machine offset
An abrupt dressing variation in the edge surface, which usually occurs near the end of the piece. It does not reduce the width or change the plane of the wide surface.
77
What is Chip Marks
Shallow depressions or indentations on the surface of dressed lumber. They occur during dressing when shavings or chips become embedded in the surface
78
What are knife marks
The imprints or markings that machine knives make on the surface of dressed lumber
79
What are the three types of building frame construction
Platform framing
Balloon framing
Post, beam and plank construction
80
What is the limit of spacing on framing members in platform framing
24 inches on center
81
What is the limit of spacing in framing members in balloon framing
24 inches
82
what is a limit of spacing of framing members and post,beam and plank construction
Anything greater than 24 inches
83
And which kind of building framing is it possible that a building inspector may require that an engineer make an on-site inspection of the engineered components
Post, Beam and plank construction
84
Which frame construction is known as Western framing
Platform-frame Construction
85
What is the most common framing system used in British Columbia
Platform-frame construction
86
In which type of framing system is the floor built first and used as a platform to build the walls which are framed independently from the floors and I lifted into place once they are squared and sheathed
Platform frame construction
87
What is the standard height of Platform frame construction framed walls
8 feet and three quarters of an inch which gives the height of approximately 8 feet after the ceiling finish and floor finish are considered
88
And platform frame construction what is the standard platform framing stud length of the walls
92 1/4 inches. Which incorporates a single bottom [sole] plate and 2 top plates
89
Which type of frame construction is also known as Eastern frame construction
Balloon-frame construction
90
Why is balloon-frame construction only used in special situations
It is very time-consuming
91
Which type of frame construction is rarely
When an entire building using balloon frame construction
92
In split-level buildings which two types of framing constructions are used together
Balloon-frame construction and platform-frame construction
93
In which type of framing construction are the studs 18 feet long and extend from the concrete at the bottom right to the top of the second floor walls
Balloon-fame construction
94
In which type of framing construction are the second floor Joists resting on a ledger that is carved into the walls
Balloon-frame construction
95
In which type of frame construction are fire stops required at each floor which prevent the stud cavity from acting as a chimney and drawing a fire from the lower floor to the floor above
Balloon-frame construction
96
Which type of framing construction consists of larger dimension members of wood that are spaced at more than 24 inches on center
Post, beam and plank construction
97
In which type of framing construction are concrete footings enlarged in area to support the concentrated loads
Post, beam and plank construction
98
If a building is made of wood frame components and has cement stucco on it which is at the same height what happens
The stucco will crumble and buckle. Therefore expansion joints are used at each floor level to allow the building to move without buckling it
99
The building is made of wood and masonry what needs to happen
A space must be left at the top of the masonry veneer so that as the wood shrinks it will not be damaged since the masonry is stronger
100
What is the benefit of balloon framing
The lack of shrinkage and settling
101
Why are post and beam components used
Their ability to create large open spaces
102
On which framing system is the standard stud length based
Standard platform framing
103
Which framing system is the fastest to construct
Platform-frame construction
104
Which part of the building code covers the design of platform framing
Part 9
105
What must be done if changes are made to the structure of a woodframe building
A complete review of design
106
Surfaced dry lumber has a moisture content of what
19% or less
107
What are actual dimensions of lumber vs nominal
.5 " less for 2"-6"
| 8,10,12 is 3/4 " less
108
if half inch drywall is used as interior finish can you use 24" studs?
yes the building code accepts it but its not adviseable as it does not allow enough support.
110
can you apply cement stucco to exterior walls withjout using wall sheathing?
yes paper backed stucco wire is applied directly to studs. although code allows 24" stud spacing 16: o.c. helps to keep the wire flat.
111
how does thermal insulation affect wall construction
minimum stud depth must be increased to accomodate the thicker insulation.
112
how many nails must be used to nail a wall stud to the plate?
either four 2.5 nails or two 3.25 end nails
113
what size and spacing must be used to nail the double top plate to the top plate on a wall
3" nails at 24" o.c. or
| walls with studs sat 16" o.c. nails are placed at stud location to keep out of way for plumbing and wiring
114
what size poly is placed as a vapour barrier between the top plate and double top plate where the ceiling above the walls is insulated
24" wide strip of 6mil poly between top plate and the double top plate
115
how are bottom or sole plates attached to joists or blocking?
nailed through the subfloor sheathing at 16" o.c. with 3.25 nails
116
AT WHAT POINT DO YOU INSULATE CONCEALED WALL STUD SPACES AT INTERSECTIONS AND CORNERS OF WALL?
prior to installing exterior sheathing
117
when must you use rigid foam insulation to fill wall cavities?
when you cant configure studs to allow for insulation to be put in after the roof is on.
118
what happens if fiberglass insulaqtion gets wet?
it reduces the insulating capabilities of the fiberglass and may cause rot in the wood-frame.
119
the size and spacing of exterior wall studs is found in which part of the building code?
part 9
