Timber

• Civil Engineering
• Foundation Degree

Timber

What are the two main categories of tree species used for timber production?

1. Softwoods and hardwoods
2. Conifers and pines
3. Heartwood and sapwood
4. Tropical and temperate

In a tree cross-section, what is the function of the cambium?

1. To store nutrients
2. To produce new wood cells
3. To protect the trunk from insects
4. To provide structural support

Which layer of wood is primarily responsible for nutrient storage and transport?

1. Heartwood
2. Sapwood
3. Cambium
4. Bark

Timber is said to be anisotropic because:

1. It has uniform properties in all directions
2. Its strength is independent of grain direction
3. Its properties vary with grain direction
4. It is unaffected by moisture

The moisture content of wood in a standard indoor environment (20 °C and 65% RH) is approximately:

1. 6%
2. 15%
3. 37.5%
4. 60%

The fibre saturation point (FSP) in most species occurs at approximately:

1. 10–15%
2. 25–35%
3. 50-65%
4. 70-80%

7. Below the fibre saturation point, a reduction in moisture content generally causes timber to:

1. Decrease in strength
2. Increase in volume
3. Increase in volume
4. Increase in strength and stiffness

8. Shrinkage in timber occurs most in which direction?

1. Longitudinal
2. Radial
3. Tangential
4. Parallel to grain

9. What is the approximate density range for softwoods used in construction?

1. 100–300 kg/m³
2. 400–650 kg/m³
3. 700–1000 kg/m³
4. 1100–1500 kg/m³

10. Knots in timber reduce strength because:

1. They are areas of higher density
2. They increase moisture absorption
3. They contain excess sap
4. They distort the grain direction