TEXAS TRADESMAN PLUMBER LIMITED
LICENSE EXAM 150 CORE TSBPE CODE
SCENARIOS WITH CORRECT VERIFIED
ANSWERS and HIGHLY DETAILED
RATIONALES GRADE A+ MASTERY
BLUEPRINT | 100% PASS GUARANTEE
[INSTANT DOWNLOAD]
Texas Tradesman Plumber-Limited License
Examination
1. A Tradesman Plumber-Limited license holder is reviewing
the scope of work they are legally permitted to perform
under the Texas State Board of Plumbing Examiners
(TSBPE) rules. Which of the following residential
configurations fits the strict limitation of this specific
license?
A) A multi-story apartment complex with 24 individual
units and a shared commercial boiler room
B) A single-family dwelling or a duplex residential
structure
C) A light commercial strip mall with a maximum of three
retail spaces
D) Any structure as long as the pipe diameter does not
exceed 2 inches
Correct Answer: B
Rationale: Under Texas law and TSBPE rules, a
Tradesman Plumber-Limited license holder is permitted
to construct, install, or repair plumbing work solely on
single-family dwellings or duplexes. They are strictly
prohibited from performing plumbing work on multi-
family apartments or commercial structures.
,2. A licensed Tradesman Plumber is installing a new
drainage pipe underneath a residential slab. According to
the International Residential Code (IRC) and Texas
mandates, what is the minimum required slope for a
horizontal drainage pipe that has a diameter of 2-1/2
inches or smaller?
A) 1/16 inch per foot
B) 1/8 inch per foot
C) 1/4 inch per foot
D) 1/2 inch per foot
Correct Answer: C
Rationale: For horizontal drainage piping with
diameters of 2-1/2 inches or smaller, the minimum slope
required to ensure adequate scouring velocity and
prevent waste blockages is 1/4 inch per foot.
3. While installing a gas-fired water heater in a residential
garage in Texas, a plumber must ensure the heating
element or pilot light is elevated to prevent the ignition of
flammable vapors. What is the minimum required height
above the garage floor for the ignition source?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Correct Answer: C
Rationale: The code mandates that any ignition source
(such as burner elements or pilots) on appliances located
in residential garages must be elevated at least 18 inches
above the floor line. This keeps the potential ignition
source above the low-lying concentration zone of
flammable automotive or fuel vapors.
4. A technician is conducting a hydrostatic water test on a
newly roughed-in residential drainage and vent system.
, According to the standard testing codes enforced in Texas,
what is the minimum water height or pressure head
required above the highest section of piping being
evaluated?
A) 2 feet of water head
B) 5 feet of water head
C) 10 feet of water head
D) 15 feet of water head
Correct Answer: B
Rationale: When performing a hydrostatic water test
on a DWV (drain, waste, and vent) system, the piping
must be filled until water flows out of the highest vent
opening, or a minimum pressure head of 5 feet of water
must be maintained on all parts of the section being
tested.
5. A Texas homeowner wants to connect their private
residential water system to a rainwater harvesting basin to
flush toilets. To protect the public water supply from
cross-contamination, what type of backflow prevention
assembly is required at the main water service entry point?
A) A basic atmospheric vacuum breaker (AVB)
B) A single check valve with an internal strainer
C) A Reduced Pressure Principle (RPZ) backflow preventer
D) No backflow preventer is required for residential
rainwater systems
Correct Answer: C
Rationale: Rainwater harvesting represents a high-
hazard cross-connection due to potential bacterial or
chemical contamination from roofs. A Reduced Pressure
Principle (RPZ) backflow assembly is mandatory at the
service connection to isolate the public potable water grid
from the auxiliary system.
, 6. Consider two components of a cleanout assembly.
Component 1: The clearance space required in front of a
cleanout for a 2-inch pipe. Component 2: The clearance
space required in front of a cleanout for a 3-inch or larger
pipe. According to the plumbing code, which statement
accurately outlines the clearance parameters?
A) Component 1 requires 12 inches, while Component 2
requires 18 inches.
B) Component 1 requires 18 inches, while Component 2
requires 24 inches.
C) Both components require a uniform clearance of 36
inches under all layout rules.
D) Component 1 requires 24 inches, while Component 2
requires 36 inches.
Correct Answer: B
Rationale: The plumbing code specifies that cleanouts
for piping 2 inches or smaller must have a minimum
configuration clearance of 18 inches in front of the
opening. Cleanouts for larger lines (3 inches and greater)
must have at least 24 inches of clearance to facilitate the
entry of mechanical sewer cleaning cables.
7. A Tradesman Plumber is running PEX (cross-linked
polyethylene) water lines through a single-family home.
When installing horizontal PEX lines, what is the
maximum allowed distance between supporting hangers
to prevent sagging?
A) 16 inches
B) 32 inches
C) 48 inches
D) 72 inches
Correct Answer: B
Rationale: Because PEX is a flexible polymer material,
it requires frequent horizontal supporting anchors to
eliminate stresses and sagging. The code sets the
LICENSE EXAM 150 CORE TSBPE CODE
SCENARIOS WITH CORRECT VERIFIED
ANSWERS and HIGHLY DETAILED
RATIONALES GRADE A+ MASTERY
BLUEPRINT | 100% PASS GUARANTEE
[INSTANT DOWNLOAD]
Texas Tradesman Plumber-Limited License
Examination
1. A Tradesman Plumber-Limited license holder is reviewing
the scope of work they are legally permitted to perform
under the Texas State Board of Plumbing Examiners
(TSBPE) rules. Which of the following residential
configurations fits the strict limitation of this specific
license?
A) A multi-story apartment complex with 24 individual
units and a shared commercial boiler room
B) A single-family dwelling or a duplex residential
structure
C) A light commercial strip mall with a maximum of three
retail spaces
D) Any structure as long as the pipe diameter does not
exceed 2 inches
Correct Answer: B
Rationale: Under Texas law and TSBPE rules, a
Tradesman Plumber-Limited license holder is permitted
to construct, install, or repair plumbing work solely on
single-family dwellings or duplexes. They are strictly
prohibited from performing plumbing work on multi-
family apartments or commercial structures.
,2. A licensed Tradesman Plumber is installing a new
drainage pipe underneath a residential slab. According to
the International Residential Code (IRC) and Texas
mandates, what is the minimum required slope for a
horizontal drainage pipe that has a diameter of 2-1/2
inches or smaller?
A) 1/16 inch per foot
B) 1/8 inch per foot
C) 1/4 inch per foot
D) 1/2 inch per foot
Correct Answer: C
Rationale: For horizontal drainage piping with
diameters of 2-1/2 inches or smaller, the minimum slope
required to ensure adequate scouring velocity and
prevent waste blockages is 1/4 inch per foot.
3. While installing a gas-fired water heater in a residential
garage in Texas, a plumber must ensure the heating
element or pilot light is elevated to prevent the ignition of
flammable vapors. What is the minimum required height
above the garage floor for the ignition source?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Correct Answer: C
Rationale: The code mandates that any ignition source
(such as burner elements or pilots) on appliances located
in residential garages must be elevated at least 18 inches
above the floor line. This keeps the potential ignition
source above the low-lying concentration zone of
flammable automotive or fuel vapors.
4. A technician is conducting a hydrostatic water test on a
newly roughed-in residential drainage and vent system.
, According to the standard testing codes enforced in Texas,
what is the minimum water height or pressure head
required above the highest section of piping being
evaluated?
A) 2 feet of water head
B) 5 feet of water head
C) 10 feet of water head
D) 15 feet of water head
Correct Answer: B
Rationale: When performing a hydrostatic water test
on a DWV (drain, waste, and vent) system, the piping
must be filled until water flows out of the highest vent
opening, or a minimum pressure head of 5 feet of water
must be maintained on all parts of the section being
tested.
5. A Texas homeowner wants to connect their private
residential water system to a rainwater harvesting basin to
flush toilets. To protect the public water supply from
cross-contamination, what type of backflow prevention
assembly is required at the main water service entry point?
A) A basic atmospheric vacuum breaker (AVB)
B) A single check valve with an internal strainer
C) A Reduced Pressure Principle (RPZ) backflow preventer
D) No backflow preventer is required for residential
rainwater systems
Correct Answer: C
Rationale: Rainwater harvesting represents a high-
hazard cross-connection due to potential bacterial or
chemical contamination from roofs. A Reduced Pressure
Principle (RPZ) backflow assembly is mandatory at the
service connection to isolate the public potable water grid
from the auxiliary system.
, 6. Consider two components of a cleanout assembly.
Component 1: The clearance space required in front of a
cleanout for a 2-inch pipe. Component 2: The clearance
space required in front of a cleanout for a 3-inch or larger
pipe. According to the plumbing code, which statement
accurately outlines the clearance parameters?
A) Component 1 requires 12 inches, while Component 2
requires 18 inches.
B) Component 1 requires 18 inches, while Component 2
requires 24 inches.
C) Both components require a uniform clearance of 36
inches under all layout rules.
D) Component 1 requires 24 inches, while Component 2
requires 36 inches.
Correct Answer: B
Rationale: The plumbing code specifies that cleanouts
for piping 2 inches or smaller must have a minimum
configuration clearance of 18 inches in front of the
opening. Cleanouts for larger lines (3 inches and greater)
must have at least 24 inches of clearance to facilitate the
entry of mechanical sewer cleaning cables.
7. A Tradesman Plumber is running PEX (cross-linked
polyethylene) water lines through a single-family home.
When installing horizontal PEX lines, what is the
maximum allowed distance between supporting hangers
to prevent sagging?
A) 16 inches
B) 32 inches
C) 48 inches
D) 72 inches
Correct Answer: B
Rationale: Because PEX is a flexible polymer material,
it requires frequent horizontal supporting anchors to
eliminate stresses and sagging. The code sets the
