Contractor Exam Questions And

CA C2 Insulation And Acoustical Contractor Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• What is the primary purpose of thermal insulation in buildings?
• Reduce structural load
• Reduce sound transmission
• Reduce heat transfer
• Provide fire resistance

Rationale: Thermal insulation is primarily used to reduce heat

transfer between interior and exterior spaces, improving energy efficiency.

• Which type of insulation is commonly used in attics?
• Fiberglass batts
• Mineral wool
• Loose-fill cellulose
• Rigid foam

Rationale: Loose-fill cellulose is ideal for attics because it can fill

irregular spaces and provide effective thermal resistance.

• What does R-value measure?
• Sound absorption
• Thermal resistance
• Fire rating
• Moisture permeability

Rationale: R-value indicates the material's resistance to heat flow;

higher R-values mean better insulation performance. 1 / 3

• Which insulation material is most resistant to fire?
• Fiberglass
• Polystyrene
• Mineral wool
• Polyurethane foam

Rationale: Mineral wool is non-combustible and can withstand high

temperatures, making it highly fire-resistant.

• In acoustical design, what does NRC stand for?
• Noise Reduction Coefficient
• Natural Resonance Coefficient
• Noise Reduction Coefficient
• Normalized Reflection Coefficient

Rationale: NRC measures the sound absorption ability of a material;

higher NRC indicates better sound absorption.

• Which insulation type is best for reducing airborne sound between

rooms?

• Spray foam
• Rigid foam
• Mineral wool or fiberglass batts
• Reflective foil

Rationale: Mineral wool and fiberglass batts absorb airborne sound

effectively, reducing noise transmission between rooms.

• What is the maximum allowable VOC content for most interior

insulation materials?

• 500 g/L
• 50 g/L
• 200 g/L
• 100 g/L

Rationale: Low-VOC materials (typically ≤50 g/L) are recommended

for indoor air quality.

• Which code governs insulation materials in California?
• International Mechanical Code
• California Building Standards Code
• National Fire Protection Code
• OSHA Standards

Rationale: The California Building Standards Code (Title 24)

includes regulations for insulation materials and installation. 2 / 3

• What is the typical density of fiberglass batt insulation?
• 0.5–1 lb/ft³
• 2–3 lb/ft³
• 1–2 lb/ft³
• 3–4 lb/ft³

Rationale: Standard fiberglass batts have densities between 1 and 2

pounds per cubic foot, suitable for residential and commercial applications.

• What is the main purpose of vapor retarders in insulation

assemblies?

• Reduce heat transfer
• Control moisture migration
• Enhance fire resistance
• Provide structural support

Rationale: Vapor retarders prevent moisture from entering

insulation, which can reduce effectiveness and cause mold growth.

• Which insulation type is best for irregularly shaped cavities?
• Fiberglass batts
• Rigid foam
• Spray foam
• Reflective foil

Rationale: Spray foam expands to fill gaps and irregular cavities,

providing both thermal insulation and air sealing.

• What is the main function of acoustical ceiling tiles?
• Fireproofing
• Thermal insulation
• Noise absorption
• Structural support

Rationale: Acoustical ceiling tiles are designed primarily to absorb

sound and reduce echo within a room.

• What type of insulation is commonly used in ductwork?
• Loose-fill cellulose
• Fiberglass batts
• Flexible fiberglass or foil-faced insulation
• Rigid foam

Rationale: Flexible fiberglass or foil-faced insulation is suitable for

wrapping ductwork to reduce heat loss or gain.

• / 3