CSLB C20 STUDY GUIDE 2026 EXAM QUESTIONS AND
ANSWERS GRADED A+
✔✔While you work with the overall, rise and run in building a roof, the slope or pitch is
based on the unit of rise and unit run. The unit that is referred to is inches.
A. 8
B. 12
C. 16
D. 24 - ✔✔B.
12 inches
✔✔Typical grading values of studs. Choose strongest to weakest:
A. utility, standard, construction, stud
B. standard, construction, stud, no. 3
C. select, no. 1, no. 2, no. 3
D. stud,no.3,no.2,no.1 - ✔✔C.
Select, no. 1, no. 2, no. 3.
✔✔What is the stud spacing supporting a roof and ceiling using 2 x 4s when NOT more
than 10 feet in height?
A. 10-in o.c.
B. 18-in o.c.
C. 12-in o.c.
D. 24-in o.c. - ✔✔D. 24-in o.c.
✔✔What is the stud spacing supporting two floors, roof and ceiling using 2 x 4s when
NOT more than 10 feet in height?
A. 24-in o.c.
B. 12-in o.c.
C. 16-in o.c.
D. not applicable - ✔✔D.
Not applicable.
✔✔Fire-stopping requires cutting off all concealed vertical and horizontal openings:
A. ,between floors and roofs, soffits, drop ceilings, cove ceilings
B. furred spaces, at ceilings and floors
C. around vents, pipes, ducts, chimneys, and fireplaces
D. All of the above - ✔✔D.
All of the above.
✔✔Rafter ties shall be spaced no more than __ feet on center.
A. 2
B. 2-1/2
C. 4
, D. None of the above - ✔✔C.
4 feet
✔✔Headers (in rafters) need to be double if spanning is more than ______?
A. 2 feet
B. 2-1/2 feet
C. 4 feet
D. 4-1/2 feet - ✔✔C.
4 feet
✔✔Truss members can or cannot be cut or can or cannot be altered?
A. can be cut ... can be altered
B. cannot be cut ... can be altered
C. can be cut ... cannot be altered
D. cannot be cut ... cannot be altered - ✔✔D.
Cannot be cut ... cannot be altered.
✔✔Top plates are to be lapped at LEAST __ inches?
A. 12
B. 16
C. 18
D. 24 - ✔✔D.
24inches
✔✔Which of the following is a truss style?
A. Lambert
B. Panel scissor
C. Briggs & Stratton
D. Inverted Belgian - ✔✔B.
A panel scissor is a style of truss.
✔✔When nailing a stud to the sole plate use:
A. 2-16d end nails or 2-16d toe nails
B. 2-16d end nails or 4-8d toe nails
C. 2-16d end nails or 4-16d toe nails
D. 4-16d end nails or 4-8d toe nails - ✔✔. B.
2-16d end nails or 4-Sd toe nails. Toe nails go in the sides or edges at an angle. End
nails go in the end of studs.
✔✔When attaching shingle siding by nailing into a shear membrane, how much
penetration should the nails have through or into the membrane?
A. 5/16"
B. 3/8"
C. 1/2"
ANSWERS GRADED A+
✔✔While you work with the overall, rise and run in building a roof, the slope or pitch is
based on the unit of rise and unit run. The unit that is referred to is inches.
A. 8
B. 12
C. 16
D. 24 - ✔✔B.
12 inches
✔✔Typical grading values of studs. Choose strongest to weakest:
A. utility, standard, construction, stud
B. standard, construction, stud, no. 3
C. select, no. 1, no. 2, no. 3
D. stud,no.3,no.2,no.1 - ✔✔C.
Select, no. 1, no. 2, no. 3.
✔✔What is the stud spacing supporting a roof and ceiling using 2 x 4s when NOT more
than 10 feet in height?
A. 10-in o.c.
B. 18-in o.c.
C. 12-in o.c.
D. 24-in o.c. - ✔✔D. 24-in o.c.
✔✔What is the stud spacing supporting two floors, roof and ceiling using 2 x 4s when
NOT more than 10 feet in height?
A. 24-in o.c.
B. 12-in o.c.
C. 16-in o.c.
D. not applicable - ✔✔D.
Not applicable.
✔✔Fire-stopping requires cutting off all concealed vertical and horizontal openings:
A. ,between floors and roofs, soffits, drop ceilings, cove ceilings
B. furred spaces, at ceilings and floors
C. around vents, pipes, ducts, chimneys, and fireplaces
D. All of the above - ✔✔D.
All of the above.
✔✔Rafter ties shall be spaced no more than __ feet on center.
A. 2
B. 2-1/2
C. 4
, D. None of the above - ✔✔C.
4 feet
✔✔Headers (in rafters) need to be double if spanning is more than ______?
A. 2 feet
B. 2-1/2 feet
C. 4 feet
D. 4-1/2 feet - ✔✔C.
4 feet
✔✔Truss members can or cannot be cut or can or cannot be altered?
A. can be cut ... can be altered
B. cannot be cut ... can be altered
C. can be cut ... cannot be altered
D. cannot be cut ... cannot be altered - ✔✔D.
Cannot be cut ... cannot be altered.
✔✔Top plates are to be lapped at LEAST __ inches?
A. 12
B. 16
C. 18
D. 24 - ✔✔D.
24inches
✔✔Which of the following is a truss style?
A. Lambert
B. Panel scissor
C. Briggs & Stratton
D. Inverted Belgian - ✔✔B.
A panel scissor is a style of truss.
✔✔When nailing a stud to the sole plate use:
A. 2-16d end nails or 2-16d toe nails
B. 2-16d end nails or 4-8d toe nails
C. 2-16d end nails or 4-16d toe nails
D. 4-16d end nails or 4-8d toe nails - ✔✔. B.
2-16d end nails or 4-Sd toe nails. Toe nails go in the sides or edges at an angle. End
nails go in the end of studs.
✔✔When attaching shingle siding by nailing into a shear membrane, how much
penetration should the nails have through or into the membrane?
A. 5/16"
B. 3/8"
C. 1/2"
