[GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
**Question 1.** Which soil test is most commonly used to determine bearing capacity for
residential footings?
A) Proctor compaction test
B) Standard penetration test (SPT)
C) Atterberg limits test
D) California bearing ratio (CBR)
Answer: B
Explanation: The SPT measures resistance of soil to penetration, providing data to calculate
bearing capacity for footings.
**Question 2.** When excavating a trench deeper than 5 ft, what OSHA requirement must be
met?
A) Use a de‑watering pump
B) Install a trench box or shoring
C) Place a concrete liner
D) Apply a dust suppressant
Answer: B
Explanation: OSHA 1926.651 requires protective systems (shoring, shielding, or sloping) for
trenches deeper than 5 ft to prevent cave‑in.
**Question 3.** The most effective erosion control method on a newly graded slope is:
A) Installing a sand blanket
B) Applying a polymer coating
C) Using straw mulch and silt fences
D) Compacting the soil with a roller
, [GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
Answer: C
Explanation: Straw mulch stabilizes the surface while silt fences capture runoff, meeting
best‑practice erosion control.
**Question 4.** For a 2‑story residential building on clay soil, the minimum footing width for a
40 k ft load is:
A) 12 in.
B) 16 in.
C) 24 in.
D) 36 in.
Answer: C
Explanation: Clay has lower bearing capacity; engineering tables typically require a 24‑in. width
for 40 k ft loads.
**Question 5.** Which factor does NOT affect footing depth?
A) Frost line depth
B) Soil bearing capacity
C) Height of the roof trusses
D) Local code requirements
Answer: C
Explanation: Roof truss height influences framing, not footing depth, which is governed by frost,
soil, and code.
**Question 6.** The purpose of a damp proof membrane (DPM) placed on a foundation wall is
to:
, [GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
A) Provide structural reinforcement
B) Prevent water vapor diffusion into the interior
C) Increase the compressive strength of concrete
D) Serve as a fire‑resistive barrier
Answer: B
Explanation: DPM stops moisture migration through the wall, protecting interior finishes.
**Question 7.** Which concrete mix design component controls air entrainment?
A) Water‑cement ratio
B) Air‑entraining admixture
C. Fly ash content
D) Coarse aggregate size
Answer: B
Explanation: Air‑entraining admixtures create microscopic air bubbles, improving freeze‑thaw
durability.
**Question 8.** A slump of 4 in. indicates:
A) Very dry mix, low workability
B) Highly fluid mix, excessive water
C) Adequate workability for most slabs
D. No slump, indicating a stiff mix
Answer: C
Explanation: A 4‑in. slump is typical for residential slabs, balancing flow and strength.
, [GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
**Question 9.** Which curing method is most appropriate for a concrete slab in hot, dry
weather?
A) Cover with plastic sheeting only
B. Apply a curing compound and keep the surface moist
C. Allow it to air‑dry for 24 hr
D. Use a high‑heat steam cure
Answer: B
Explanation: Curing compounds retain moisture; combined with periodic water application they
prevent rapid drying.
**Question 10.** The minimum concrete cover for #5 rebar in exterior footings exposed to
freeze‑thaw is:
A) ½ in.
B) ¾ in.
C) 1 in.
D) 1½ in.
Answer: C
Explanation: IBC/ACI require at least 1 in. cover for #5 rebar in exterior, freeze‑thaw conditions.
**Question 11.** When constructing a slab‑on‑grade for a light‑commercial building, the
recommended subbase thickness is:
A) 2 in. granular fill only
B) 4 in. compacted sand
C) 6‑8 in. crushed stone
D. 12 in. compacted clay
Commercial Contractor Certification Exam
Preparation
**Question 1.** Which soil test is most commonly used to determine bearing capacity for
residential footings?
A) Proctor compaction test
B) Standard penetration test (SPT)
C) Atterberg limits test
D) California bearing ratio (CBR)
Answer: B
Explanation: The SPT measures resistance of soil to penetration, providing data to calculate
bearing capacity for footings.
**Question 2.** When excavating a trench deeper than 5 ft, what OSHA requirement must be
met?
A) Use a de‑watering pump
B) Install a trench box or shoring
C) Place a concrete liner
D) Apply a dust suppressant
Answer: B
Explanation: OSHA 1926.651 requires protective systems (shoring, shielding, or sloping) for
trenches deeper than 5 ft to prevent cave‑in.
**Question 3.** The most effective erosion control method on a newly graded slope is:
A) Installing a sand blanket
B) Applying a polymer coating
C) Using straw mulch and silt fences
D) Compacting the soil with a roller
, [GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
Answer: C
Explanation: Straw mulch stabilizes the surface while silt fences capture runoff, meeting
best‑practice erosion control.
**Question 4.** For a 2‑story residential building on clay soil, the minimum footing width for a
40 k ft load is:
A) 12 in.
B) 16 in.
C) 24 in.
D) 36 in.
Answer: C
Explanation: Clay has lower bearing capacity; engineering tables typically require a 24‑in. width
for 40 k ft loads.
**Question 5.** Which factor does NOT affect footing depth?
A) Frost line depth
B) Soil bearing capacity
C) Height of the roof trusses
D) Local code requirements
Answer: C
Explanation: Roof truss height influences framing, not footing depth, which is governed by frost,
soil, and code.
**Question 6.** The purpose of a damp proof membrane (DPM) placed on a foundation wall is
to:
, [GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
A) Provide structural reinforcement
B) Prevent water vapor diffusion into the interior
C) Increase the compressive strength of concrete
D) Serve as a fire‑resistive barrier
Answer: B
Explanation: DPM stops moisture migration through the wall, protecting interior finishes.
**Question 7.** Which concrete mix design component controls air entrainment?
A) Water‑cement ratio
B) Air‑entraining admixture
C. Fly ash content
D) Coarse aggregate size
Answer: B
Explanation: Air‑entraining admixtures create microscopic air bubbles, improving freeze‑thaw
durability.
**Question 8.** A slump of 4 in. indicates:
A) Very dry mix, low workability
B) Highly fluid mix, excessive water
C) Adequate workability for most slabs
D. No slump, indicating a stiff mix
Answer: C
Explanation: A 4‑in. slump is typical for residential slabs, balancing flow and strength.
, [GRLCC] Georgia Residential Light
Commercial Contractor Certification Exam
Preparation
**Question 9.** Which curing method is most appropriate for a concrete slab in hot, dry
weather?
A) Cover with plastic sheeting only
B. Apply a curing compound and keep the surface moist
C. Allow it to air‑dry for 24 hr
D. Use a high‑heat steam cure
Answer: B
Explanation: Curing compounds retain moisture; combined with periodic water application they
prevent rapid drying.
**Question 10.** The minimum concrete cover for #5 rebar in exterior footings exposed to
freeze‑thaw is:
A) ½ in.
B) ¾ in.
C) 1 in.
D) 1½ in.
Answer: C
Explanation: IBC/ACI require at least 1 in. cover for #5 rebar in exterior, freeze‑thaw conditions.
**Question 11.** When constructing a slab‑on‑grade for a light‑commercial building, the
recommended subbase thickness is:
A) 2 in. granular fill only
B) 4 in. compacted sand
C) 6‑8 in. crushed stone
D. 12 in. compacted clay
