WOOD

Question 1

Wood

Answer 1

A commonly used construction material due to its reasonable cost—ease of working—and durability.

Question 2

Types of wood

Answer 2

Hardwood from deciduous trees (angiosperms)—and softwood from coniferous trees (gymnosperms).

Question 3

Reasons for using wood in construction

Answer 3

It is affordable—easy to work with—visually appealing—and durable when properly maintained.

Question 4

Hardwood examples

Answer 4

Oak—mahogany—teak—maple—walnut—and cherry.

Question 5

Softwood examples

Answer 5

Pine—cedar—spruce—fir—and redwood.

Question 6

Uses of hardwood

Answer 6

Commonly used for furniture—flooring—tool handles—and high-strength applications.

Question 7

Uses of softwood

Answer 7

Used for framing—plywood—doors—and general construction.

Question 8

Mechanical properties of wood

Answer 8

Strength—hardness—stiffness—toughness—warping—nail-holding resistance—and workability.

Question 9

Strength of wood

Answer 9

The ability to resist breaking when used in beams and columns—influenced by species—moisture—and density.

Question 10

Factors affecting wood strength

Answer 10

Moisture content (MC)—knots—checks—splits—and irregular grain patterns.

Question 11

Effects of high moisture content

Answer 11

Weakens wood and makes it prone to warping and decay.

Question 12

Knots in wood

Answer 12

Circular—hard portions caused by branches that may weaken the structure and affect workability.

Question 13

Checks and splits in wood

Answer 13

Cracks in wood that develop due to drying stress—reducing its strength.

Question 14

Irregular grain patterns

Answer 14

Occur when wood fibers grow in different directions—making it harder to cut and shape.

Question 15

Hardness of wood

Answer 15

Resistance to denting and wear—important for flooring—tool handles—and surfaces requiring durability.

Question 16

Hardness testing method

Answer 16

Janka Hardness Test developed by Gabriel Janka—using a steel ball to measure resistance.

Question 17

Janka test process

Answer 17

Measures the force needed to embed an 11.28mm steel ball halfway into a wood sample.

Question 18

Common uses of hardwoods

Answer 18

Used in flooring—furniture—tool handles—and areas with high wear resistance.

Question 19

Softwood hardness

Answer 19

Generally softer than hardwoods—making them easier to cut—shape—and finish.

Question 20

Stiff woods

Answer 20

Resist bending or deflection under load—but may break suddenly if overloaded.

Question 21

Tough woods

Answer 21

Can absorb shock and resist sudden forces without breaking easily.

Question 22

Examples of tough woods

Answer 22

Hickory—ash—and oak—which resist impacts and sudden loads.

Question 23

Warping

Answer 23

The twisting—bending—or bowing of wood due to uneven moisture content changes.

Question 24

Causes of warping

Answer 24

Uneven drying—improper storage—and variations in temperature and humidity.

Question 25

Ways to prevent warping

Answer 25

Store wood properly—seal it—and control moisture exposure.

Question 26

Nail-holding resistance

Answer 26

The ability of wood to hold nails securely—pre-boring holes reduces splitting.

Question 27

Best woods for nail-holding

Answer 27

Oak—pine—and fir—which provide a strong grip for fasteners.

Question 28

Workability of wood

Answer 28

How easily wood can be cut—shaped—and finished—softwoods are easier to work with than hardwoods.

Question 29

Best woods for workability

Answer 29

Pine—cedar—and poplar—which are easier to cut and shape.

Question 30

Difficult woods to work with

Answer 30

Teak—mahogany—and ebony—which are dense and require specialized tools.

Question 31

Natural decay resistance

Answer 31

The ability of wood to resist fungi—bacteria—and insects—affecting its durability.

Question 32

Decay-resistant woods

Answer 32

Cedar—redwood—and teak—which naturally repel moisture and pests.

Question 33

Ways to increase wood durability

Answer 33

Chemical treatments—painting—sealing—and proper ventilation.

Question 34

Paint-holding capacity

Answer 34

The ability of wood to retain paint without peeling—cracking—or flaking over time.

Question 35

Best woods for painting

Answer 35

Pine—fir—and poplar—which absorb paint evenly.

Question 36

Worst woods for painting

Answer 36

Oily woods like teak and mahogany—which resist paint adhesion.

Question 37

Physical properties of wood

Answer 37

Color—luster/grain—texture—and density.

Question 38

Wood color

Answer 38

Ranges from light (softwoods) to dark (hardwoods)—affected by age—sunlight—and stains.

Question 39

Luster/grain

Answer 39

Describes wood's surface reflectivity and the natural pattern formed by its fibers.

Question 40

Texture of wood

Answer 40

Can be smooth—rough—or figured—depending on grain pattern and density.

Question 41

Wood density

Answer 41

The mass per unit volume—denser woods are heavier—harder—and more durable.

Question 42

Density classifications

Answer 42

Very light (<0.36 g/cm³)—light (0.36 g/cm³)—moderately heavy (0.36–0.5 g/cm³)—heavy (>0.5 g/cm³).

Question 43

Effects of high-density wood

Answer 43

Harder to cut and shape—but stronger and more durable.

Question 44

Effects of low-density wood

Answer 44

Easier to work with—but less durable and more prone to dents.

Question 45

Construction material selection

Answer 45

Depends on cost—durability—availability—labor—transportation—and compatibility with other materials.

Question 46

Economic considerations in material selection

Answer 46

Balancing initial investment—maintenance costs—and long-term durability.

Question 47

Transportation cost factor

Answer 47

Heavy materials like oak and mahogany increase shipping expenses.

Question 48

Cultural acceptability in wood selection

Answer 48

Some regions prefer locally available or traditional woods for cultural—or environmental reasons.