CSLB B LICENSE GENERAL CONTRACTOR EXAM
Complete Practice Examination - 2026 Edition
actual!!!!
1. If unused mortar stiffens due to hydration of cement, what must you do?
A) Add water and remix
B) Add more cement and remix
C) Discard the mortar
D) Let it sit for 24 hours then reuse
ANSWER: C) Discard the mortar
Rationale: A) Adding water after hydration has begun weakens the mortar and reduces its bonding
strength. B) Adding more cement does not reverse the chemical process of hydration that has already
occurred. C) Correct - Once mortar stiffens due to hydration, the chemical reaction cannot be reversed;
re-tempering weakens the mortar significantly. D) Waiting longer only allows more hydration to occur,
making the mortar even harder and less workable.
2. What minimum time must you wait before caulking or grouting new tiles?
A) 12 hours
B) 24-48 hours
C) 72 hours
,D) 1 week
ANSWER: B) 24-48 hours
Rationale: A) 12 hours is insufficient time for the tile adhesive or thinset to properly cure and set. B)
Correct - Waiting 24-48 hours ensures the tile installation has properly cured before applying grout or
caulk. C) 72 hours is longer than necessary and would delay construction unnecessarily. D) One week is
excessive and not required for standard tile installations.
3. How long should you wait before installing tile on a shower pan?
A) Immediately after installation
B) 12 hours
C) 24 hours
D) 48 hours
ANSWER: C) 24 hours
Rationale: A) Installing tile immediately does not allow the shower pan to set and cure properly. B) 12
hours is insufficient for proper curing of the shower pan materials. C) Correct - The shower pan needs 24
hours to cure before tile installation to ensure proper waterproofing and structural integrity. D) 48 hours
is longer than necessary and would cause project delays.
4. Unstable dry rock, angular gravel, sandy loam, and cohesive soils having compressive strengths
greater than 0.5 and less than 1.5 tons/sq ft (tsf), are typical examples of:
A) Type-A Soils
B) Type-B Soils
C) Type-C Soils
D) Stable Rock
,ANSWER: B) Type-B Soils
Rationale: A) Type-A soils have compressive strengths greater than 1.5 tsf and are more stable. B)
Correct - Type-B soils have compressive strengths between 0.5 and 1.5 tsf and include the materials
described. C) Type-C soils have compressive strengths less than 0.5 tsf and are less stable. D) Stable rock
is solid, intact rock that is not subject to the same classification criteria.
5. If 65 street lights are fed by a 2275 volt series circuit, what is the voltage across each light?
A) 25V
B) 30V
C) 35V
D) 45V
ANSWER: C) 35V
Rationale: A) 25V would result from dividing by 91 lights, which is incorrect. B) 30V would result from
dividing by 75.8 lights, which is not the given number. C) Correct - In a series circuit, total voltage is
divided equally among all loads: 2275 ÷ 65 = 35V. D) 45V would result from dividing by approximately
50.5 lights, which is incorrect.
6. For safety reasons, the maximum simple slope of an excavation, up to 20 ft deep, in Type-B soil is:
A) 3/4:1 (53°)
B) 1:1 (45°)
C) 1½:1 (34°)
D) 2:1 (26°)
ANSWER: B) 1:1 (45°)
, Rationale: A) 3/4:1 is too steep for Type-B soil and would be unsafe. B) Correct - OSHA requires Type-B
soil excavations up to 20 feet deep to have a maximum slope of 1:1 (45 degrees). C) 1½:1 is the
requirement for Type-C soil, which is less stable. D) 2:1 is excessively conservative for Type-B soil and
would require unnecessary excavation.
7. A Pittsburgh joint is used in:
A) Plumbing pipe connections
B) HVAC ductwork
C) Electrical conduit
D) Structural steel framing
ANSWER: B) HVAC ductwork
Rationale: A) Plumbing pipe connections use different types of joints such as soldered, threaded, or
glued connections. B) Correct - A Pittsburgh joint is a specific type of seam used in heating, ventilation,
and air conditioning ductwork fabrication. C) Electrical conduit uses threaded or compression fittings. D)
Structural steel framing uses welded or bolted connections.
8. The drain for a pressure relief valve on a water heater should be extended to:
A) The nearest floor drain
B) The outside of the building
C) A sanitary sewer line
D) A catch basin
ANSWER: B) The outside of the building
Rationale: A) Floor drains can become clogged and may not handle the discharge properly. B) Correct -
Pressure relief valve drains must discharge to the outside of the building to prevent scalding and water
damage inside the structure. C) Connecting to sanitary sewer lines is not permitted due to potential
contamination and pressure issues. D) Catch basins are not appropriate for this application.
Complete Practice Examination - 2026 Edition
actual!!!!
1. If unused mortar stiffens due to hydration of cement, what must you do?
A) Add water and remix
B) Add more cement and remix
C) Discard the mortar
D) Let it sit for 24 hours then reuse
ANSWER: C) Discard the mortar
Rationale: A) Adding water after hydration has begun weakens the mortar and reduces its bonding
strength. B) Adding more cement does not reverse the chemical process of hydration that has already
occurred. C) Correct - Once mortar stiffens due to hydration, the chemical reaction cannot be reversed;
re-tempering weakens the mortar significantly. D) Waiting longer only allows more hydration to occur,
making the mortar even harder and less workable.
2. What minimum time must you wait before caulking or grouting new tiles?
A) 12 hours
B) 24-48 hours
C) 72 hours
,D) 1 week
ANSWER: B) 24-48 hours
Rationale: A) 12 hours is insufficient time for the tile adhesive or thinset to properly cure and set. B)
Correct - Waiting 24-48 hours ensures the tile installation has properly cured before applying grout or
caulk. C) 72 hours is longer than necessary and would delay construction unnecessarily. D) One week is
excessive and not required for standard tile installations.
3. How long should you wait before installing tile on a shower pan?
A) Immediately after installation
B) 12 hours
C) 24 hours
D) 48 hours
ANSWER: C) 24 hours
Rationale: A) Installing tile immediately does not allow the shower pan to set and cure properly. B) 12
hours is insufficient for proper curing of the shower pan materials. C) Correct - The shower pan needs 24
hours to cure before tile installation to ensure proper waterproofing and structural integrity. D) 48 hours
is longer than necessary and would cause project delays.
4. Unstable dry rock, angular gravel, sandy loam, and cohesive soils having compressive strengths
greater than 0.5 and less than 1.5 tons/sq ft (tsf), are typical examples of:
A) Type-A Soils
B) Type-B Soils
C) Type-C Soils
D) Stable Rock
,ANSWER: B) Type-B Soils
Rationale: A) Type-A soils have compressive strengths greater than 1.5 tsf and are more stable. B)
Correct - Type-B soils have compressive strengths between 0.5 and 1.5 tsf and include the materials
described. C) Type-C soils have compressive strengths less than 0.5 tsf and are less stable. D) Stable rock
is solid, intact rock that is not subject to the same classification criteria.
5. If 65 street lights are fed by a 2275 volt series circuit, what is the voltage across each light?
A) 25V
B) 30V
C) 35V
D) 45V
ANSWER: C) 35V
Rationale: A) 25V would result from dividing by 91 lights, which is incorrect. B) 30V would result from
dividing by 75.8 lights, which is not the given number. C) Correct - In a series circuit, total voltage is
divided equally among all loads: 2275 ÷ 65 = 35V. D) 45V would result from dividing by approximately
50.5 lights, which is incorrect.
6. For safety reasons, the maximum simple slope of an excavation, up to 20 ft deep, in Type-B soil is:
A) 3/4:1 (53°)
B) 1:1 (45°)
C) 1½:1 (34°)
D) 2:1 (26°)
ANSWER: B) 1:1 (45°)
, Rationale: A) 3/4:1 is too steep for Type-B soil and would be unsafe. B) Correct - OSHA requires Type-B
soil excavations up to 20 feet deep to have a maximum slope of 1:1 (45 degrees). C) 1½:1 is the
requirement for Type-C soil, which is less stable. D) 2:1 is excessively conservative for Type-B soil and
would require unnecessary excavation.
7. A Pittsburgh joint is used in:
A) Plumbing pipe connections
B) HVAC ductwork
C) Electrical conduit
D) Structural steel framing
ANSWER: B) HVAC ductwork
Rationale: A) Plumbing pipe connections use different types of joints such as soldered, threaded, or
glued connections. B) Correct - A Pittsburgh joint is a specific type of seam used in heating, ventilation,
and air conditioning ductwork fabrication. C) Electrical conduit uses threaded or compression fittings. D)
Structural steel framing uses welded or bolted connections.
8. The drain for a pressure relief valve on a water heater should be extended to:
A) The nearest floor drain
B) The outside of the building
C) A sanitary sewer line
D) A catch basin
ANSWER: B) The outside of the building
Rationale: A) Floor drains can become clogged and may not handle the discharge properly. B) Correct -
Pressure relief valve drains must discharge to the outside of the building to prevent scalding and water
damage inside the structure. C) Connecting to sanitary sewer lines is not permitted due to potential
contamination and pressure issues. D) Catch basins are not appropriate for this application.
