Deck 13: Materials for Wood Construction-I Lumber

Question 1

The walls of wood cells consist primarily of

A)copper.
B)glucose.
C)calcium.
D)lignin.
E)cellulose.

Answer 1

E

Question 2

Hardwoods are generally used for fine- quality flooring, furniture, and wall paneling.

Answer 2

True

Question 3

Which of the following two terms are used synonymously?

A)Lumber and solid sawn lumber
B)Lumber and wood
C)Lumber and laminated veneer lumber
D)All of the above

Answer 3

A

Question 4

Redwood is grown mainly in

A)Florida.
B)Texas.
C)Oklahoma.
D)California.
E)Arizona.

Question 5

Spruce is a softwood species.

Question 6

Which of the following species of wood is not a hardwood?

A)Balsa wood
B)Teak
C)Redwood
D)Oak
E)Rosewood

Question 7

Which of the following species of wood is naturally decay resistant?

A)Spruce
B)Pine
C)Cedar
D)Hemlock
E)Fir

Question 8

The difference between softwoods and hardwoods is based on the

A)density of wood.
B)abrasion resistance of wood.
C)decay resistance of wood.
D)botanical characteristics.
E)strength of wood.

Question 9

Which of the following species of wood is not a softwood?

A)Oak
B)Pine
C)Fir
D)Cedar
E)Redwood

Question 10

The terms sapwood and heartwood refer to

A)two different parts of the same tree.
B)two different wood species.
C)two different types of wood cells.
D)two different subspecies of wood.
E)two different parts of a growth ring.

Question 11

Lumber used for structural framing of buildings in North America is generally derived

A)from softwood species.
B)from hardwood species.
C)from both softwoods and hardwoods, depending on the price of lumber.
D)from both softwoods and hardwoods, depending on the time of the year.

Question 12

In a 2 × 6 stud, the wood grain is parallel to the

A)vertical direction.
B)6- in. dimension.
C)2- in. dimension.

Question 13

Which of the following terms means the same as quarter- sawn?

A)Radially sawn
B)Tangentially sawn

Question 14

Flat- sawn lumber is dimensionally more stable than quarter- sawn lumber.

Question 15

Wood is

A)stronger across the grain than along the grain.
B)equally strong in both directions of the grain.
C)stronger along the grain than across the grain.

Question 16

In the United States, most structural lumber is grown in the

A)western and southern regions of the United States.
B)eastern and northeastern regions of the United States.
C)central region of the United States.
D)northern region of the United States.
E)none of the above, because most structural lumber is imported from Mexico.

Question 17

The approximate density of lumber is

A)55 psf.
B)55 pcf.
C)35 psf.
D)75 pcf.
E)35 pcf.

Question 18

The cellular structure of wood consists mainly of

A)hollow, small, approximately spherical cells.
B)solid, small, approximately spherical cells.
C)hollow, long tubular cells.
D)hollow, small, approximately ellipsoidal cells.
E)either C or D.

Question 19

If we cut a cross section through a tree trunk, we will see a number of rings. The most appropriate term for these rings is

A)annual rings.
B)eccentric rings.
C)concentric rings.
D)growth rings.
E)all of the above.

Question 20

Structural lumber is typically

A)flat- sawn.
B)quarter- sawn.
C)either A or B, depending on the type of structural member.

Question 21

A 10- ft- long stud was installed in position when the wood's moisture content was 19%. During a long dry spell, the wood's moisture content became 8%. The new stud length will be

A)approximately 9 ft 11 in.
B)approximately the same as the initial stud length of 10 ft.
C)approximately 9 ft 10 in.
D)approximately 9 ft 10- 1/2 in.
E)none of the above.

Question 22

Which of the following grades can only be used as blocking?

A)No. 1
B)No. 2
C)Utility
D)Standard
E)Construction

Question 23

Which of the following lumber cross sections is that of a dimension lumber?

A)6 × 8
B)1 × 12
C)4 × 8
D)1 × 8
E)6 × 12

Question 24

The actual dimensions of 2 × 12 lumber are

A)1- 1/2 in. × 11 in.
B)1- 3/4 in. × 11- 3/4 in.
C)1- 1/2 in. × 11- 1/2 in.
D)1- 1/2 in. × 11- 3/4 in.
E)none of the above.

Question 25

Which of the following is not a lumber grade?

A)No. 1
B)No. 2
C)No. 3
D)No. 4
E)Construction

Question 26

Which of the following grades will not apply to a 2 × 8 lumber?

A)No. 1
B)No. 2
C)No. 3
D)Construction

Question 27

The weight of a piece of lumber is 2 lb. The weight of the same piece after it is fully dried is 1.8 lb. What was the original moisture content in the wood?

A)9%
B)15%
C)11%
D)7%
E)None of the above

Question 28

The term S- DRY implies that the lumber has been

A)sawed when its moisture content was c 25%.
B)surfaced when its moisture content was c 25%.
C)surfaced when its moisture content was c 19%.
D)sawed when its moisture content was c 19%.
E)stored in a dry climate.

Question 29

A lumber grade stamp must include information on the cross- sectional dimensions of lumber.

Question 30

A retailer of building materials purchased 1,000 pieces of 2 × 12 lumber, each 10 ft long. How many board feet did the retailer purchase?

A)20,000 bd ft
B)1,000 bd ft
C)100,000 bd ft
D)10 MBF
E)None of the above

Question 31

A piece of lumber has been specified as 2 in. × 4 in. in cross section. This refers to its

A)nominal cross- sectional dimensions.
B)actual cross- sectional dimensions.

Question 32

In calculating the board foot measure, we must use the actual dimensions of lumber, not its nominal dimensions.

Question 33

The moisture content in a piece of lumber has been measured to be 15%. According to the wood industry, this piece of lumber will be classified as

A)dry.
B)arid.
C)green.
D)moist.
E)wet.

Question 34

The actual dimensions of 4 × 8 lumber are

A)3- 1/4 in. × 7- 1/4 in.
B)3- 1/4 in. × 7- 1/2 in.
C)3- 1/2 in. × 7- 1/2 in.
D)3- 1/2 in. × 7- 1/4 in.
E)none of the above.

Question 35

The term S2S implies that the lumber has been

A)sawed from two sides.
B)surfaced on two sides.
C)sawed twice.
D)none of the above.

Question 36

Lumber used for structural framing members, such as studs, floor joists, and rafters, is graded using

A)only machine grading.
B)only visual inspection.
C)Both visual and machine grading must be used to arrive at lumber's grade.

Question 37

Fungal decay in wood occurs when the moisture content in wood is

A)greater than or equal to 15%.
B)greater than or equal to 20%.
C)between 15% and 25%.
D)greater than or equal to 25%.
E)none of the above.

Question 38

From the user's viewpoint, the difference between MC 15 and KD 15 is generally ignored.

Question 39

A lumber grade stamp must include the mill identification number.

Question 40

The basis for distinguishing lumber as board, dimension lumber, and timber is the

A)length of lumber.
B)durability of lumber.
C)species of lumber.
D)cross- sectional dimensions of lumber.
E)strength of lumber.

Question 41

What is photosynthesis?

Question 42

Lumber is classified as green or dry, depending on whether the moisture content (MC)in wood is c 20% or c 19% respectively. What is the rationale behind these MC values?

Question 43

A typical lumber manufacturing plant has a reservoir of water. What is its purpose?

Question 44

Trees from which lumber is obtained are divided into two broad categories-softwood trees and hardwood trees. Which one of these types is more abundant in North America and which one is faster growing?

Question 45

Trees from which lumber is obtained are divided into two broad categories-softwood trees and hardwood trees. Is the distinction between the two based on the strength of wood obtained from them, their botanical differences, or both? Explain.

Question 46

Lumber can be flat sawn or radial sawn. Of the two, radial- sawn lumber is more wasteful of wood. Why then is it used?

Question 47

A wood member's strength properties are dependent on grain direction. In a wood stud, is the grain aligned vertically or horizontally? In which direction is the grain aligned in a wood beam or joist?

Question 48

A wood member weighs 10 lb. It is now fully dried, i.e., until it contains no water. Its dry weight is 8 lb. What was the moisture content (MC)in its original, moist condition?

Question 49

Preservative- treated lumber is effective

A)only against termite attack.
B)only against fungal attack.
C)against both fungi and termites.

Question 50

Trees from which lumber is obtained are divided into two broad categories-softwood trees and hardwood trees
-based on their botanical characteristics, such as the type of leaves, evergreen or deciduous trees, and whether the trees bear flowers or not. What are the characteristics of softwood trees?

Question 51

Heartwood and sapwood are two parts of the same tree trunk. Which one of these parts is the older part and which one contains minerals (sucked from the ground)that are deposited in its cell cavities?

Question 52

What is the typical moisture content in a wood member at fiber saturation point?

Question 53

Hardwood species are generally stronger than softwood species. So, why are softwood species generally used in structural framing members?

Question 54

A termite shield is generally made of

A)galvanized sheet steel.
B)kraft paper.
C)lead sheet.
D)asphalt- treated felt.

Question 55

What is fiber- saturation point (FSP)with respect to wood?

Question 56

Trees from which lumber is obtained are divided into two broad categories-softwood trees and hardwood trees. Is the wood from both categories used in structural framing members, such as studs, joists, beams, columns, etc.? Explain.

Question 57

Is it the heartwood or the sapwood (of some wood species)that is recognized as decay resistant? Name these species.

Question 58

What is (are)the essential difference(s)between the materials called lumber, sold lumber, and solid sawn lumber?

Question 59

Lumber is classified as green or dry. Explain the difference between the two.

Question 60

Wood certified by the Forest Stewardship Council (FSC)is available

A)in the United States and Canada.
B)only in the United States.
C)in the United States, Canada, and Mexico.
D)in C and several other countries.

Question 61

Describe the essential differences between softwood and hardwood trees. Give at least three commonly used species of each.

Question 62

Can a 2 × 4 member carry the grade of "No.1"? The grade of "Select Structural"?

Question 63

How can fungal decay of lumber be prevented?

Question 64

Will two 2 × 8 lumber members nailed together yield one 4 × 8 lumber member? Explain.

Question 65

What are the actual dimensions of a 3 × 8 lumber? Of a 4 × 12 lumber?

Question 66

Most lumber used in building construction is visually graded. The traditional visual grading was done by trained graders, who would examine each lumber member for the straightness of grain and the number and size of defects (knots, shakes, and splits)and mark the appropriate grade on the member based on visual assessment. Recently, this procedure has been replaced by an alternative procedure. What is this new procedure called, and what is the fundamental difference between the new and the traditional procedure?

Question 67

Is 6 × 8 lumber member "board lumber," "dimension lumber" or "timber"?

Question 68

The biodeterioration of wood can occur in two ways. Name them.

Question 69

Lumber can be seasoned (i.e., dried)using two methods. Name them and identify the one that is commonly used and why.

Question 70

Is 4 × 12 lumber member "board lumber," "dimension lumber" or "timber"?

Question 71

Is fire- retardant- treated (FRT)wood considered by codes as noncombustible material? Explain.

Question 72

Among the 2- by members, the grade of "Stud" is limited to certain cross- sectional sizes. Which are those sizes?

Question 73

What is seasoning of lumber?

Question 74

What is fire- retardant- treated (FRT)wood?

Question 75

How can termite infestation of lumber be prevented?

Question 76

Among the 2- by members, the grades of "Construction," "Standard," and "Utility" are limited to a certain cross- sectional size. Which size is that size?

Question 77

Why does a knot present an area of weakness in a lumber member?

Question 78

After debarking, a log is sawn to required lengths and required cross- sectional sizes. Sawing renders lumber members rough to touch, which can hurt a carpenter's hands. Therefore, the sawn lumber is subsequently surfaced smooth with planing machines. Is surfacing done after the seasoning of lumber or before? Give reason for your answer.

Question 79

What are the current limitations on the use of finger- jointed lumber members in structural applications?

Question 80

We often see a lumber grade stamp with an "S- P- F" mark, implying that the lumber species may be Spruce, Pine, or Fir. "Hem- Fir" mark is another example of combining two or more species-Hemlock and Fir. What is the reason for combining different species into one group?