CSRC Sputum Bowl Questions and
Answers 2025 — Complete Study
Guide for Respiratory Therapy
Student
Questions 1-100
Section 1: Materials and Tools (Questions 1-20)
1. What is the primary purpose of "brown coat" in a three-coat plaster system?
a) To provide a smooth, final decorative surface
b) To act as a bonding layer between the scratch coat and the finish coat
c) To build thickness, level the surface, and provide strength
d) To waterproof the substrate
Correct Answer: c) To build thickness, level the surface, and provide strength
Rationale: The scratch coat provides the key, the brown coat builds the mass and true
surface, and the finish coat provides the texture/color.
,2. What is the maximum allowable span for 3/8-inch diamond mesh metal lath
when applied to ceilings?
a) 12 inches
b) 16 inches
c) 24 inches
d) 32 inches
Correct Answer: a) 12 inches
Rationale: To prevent sagging and "drumminess," metal lath on ceilings requires closer
support (usually 6" to 12") depending on the lath type and weight, but 12" is a common
maximum for 3/8" rib lath on ceilings.
3. Which type of gypsum lath is specifically designed to provide fire resistance?
a) Plain gypsum lath
b) Perforated gypsum lath
c) Foil-backed gypsum lath
d) Type X gypsum lath
Correct Answer: d) Type X gypsum lath
Rationale: Type X board contains glass fibers and other additives in the core to increase
fire resistance.
4. Hydrated lime is added to plaster mixes primarily for:
a) Increasing compressive strength
b) Accelerating setting time
c) Improving workability and plasticity
d) Reducing cracking due to thermal expansion
Correct Answer: c) Improving workability and plasticity
Rationale: Lime makes the mortar "buttery" and easier to work with, and helps it stick to
the trowel and wall.
,5. A "hawk" is a tool used for:
a) Cutting metal lath
b) Holding and carrying plaster
c) Texturing the finish coat
d) Applying the scratch coat to corners
Correct Answer: b) Holding and carrying plaster
Rationale: The plasterer holds the hawk in one hand and uses the trowel to take plaster
from it to apply to the wall.
6. What is the purpose of "beads" (corner beads) in plastering?
a) To provide a decorative edge
b) To act as a screed for plaster thickness and protect the corner
c) To create an expansion joint
d) To separate different plaster types
Correct Answer: b) To act as a screed for plaster thickness and protect the corner
Rationale: Corner beads provide a true, straight edge and a durable metal nose for
external corners.
7. Which material is most commonly used for the finish coat in a traditional NYC
interior plaster job?
a) Portland cement
b) Gauging plaster (Plaster of Paris) and lime putty
c) Fireclay
d) Acrylic stucco
Correct Answer: b) Gauging plaster (Plaster of Paris) and lime putty
Rationale: This is the traditional "gauged lime putty" finish, which hardens quickly and
provides a smooth white surface.
8. When applying portland cement plaster (stucco) on the exterior, what is the
purpose of "curing"?
, a) To make the surface white
b) To prevent the plaster from freezing
c) To retain moisture to allow the cement to properly hydrate and gain strength
d) To speed up the evaporation process
Correct Answer: c) To retain moisture to allow the cement to properly hydrate
and gain strength
Rationale: Cement requires water to cure. If it dries out too fast, it will crack and have
low strength. This is often done by misting with water.
9. What is "Plaster Weld" or similar bonding agents used for?
a) Mixing into the finish coat for color
b) Applying over dense concrete surfaces to help the scratch coat bond
c) Cleaning trowels after use
d) Waterproofing the brown coat
Correct Answer: b) Applying over dense concrete surfaces to help the scratch coat
bond
Rationale: These are acrylic bonding agents used on smooth, non-porous surfaces (like
concrete columns) where a mechanical key is insufficient.
10. "Self-furring" metal lath has dimples or indentations to:
a) Make it easier to cut
b) Create a small gap between the lath and the waterproof paper/backing
c) Add decorative texture to the wall
d) Interlock with adjacent sheets
Correct Answer: b) Create a small gap between the lath and the waterproof
paper/backing
Rationale: This "furring" space allows plaster to flow around the lath, completely
embedding it, which prevents rust and provides a stronger key.
Answers 2025 — Complete Study
Guide for Respiratory Therapy
Student
Questions 1-100
Section 1: Materials and Tools (Questions 1-20)
1. What is the primary purpose of "brown coat" in a three-coat plaster system?
a) To provide a smooth, final decorative surface
b) To act as a bonding layer between the scratch coat and the finish coat
c) To build thickness, level the surface, and provide strength
d) To waterproof the substrate
Correct Answer: c) To build thickness, level the surface, and provide strength
Rationale: The scratch coat provides the key, the brown coat builds the mass and true
surface, and the finish coat provides the texture/color.
,2. What is the maximum allowable span for 3/8-inch diamond mesh metal lath
when applied to ceilings?
a) 12 inches
b) 16 inches
c) 24 inches
d) 32 inches
Correct Answer: a) 12 inches
Rationale: To prevent sagging and "drumminess," metal lath on ceilings requires closer
support (usually 6" to 12") depending on the lath type and weight, but 12" is a common
maximum for 3/8" rib lath on ceilings.
3. Which type of gypsum lath is specifically designed to provide fire resistance?
a) Plain gypsum lath
b) Perforated gypsum lath
c) Foil-backed gypsum lath
d) Type X gypsum lath
Correct Answer: d) Type X gypsum lath
Rationale: Type X board contains glass fibers and other additives in the core to increase
fire resistance.
4. Hydrated lime is added to plaster mixes primarily for:
a) Increasing compressive strength
b) Accelerating setting time
c) Improving workability and plasticity
d) Reducing cracking due to thermal expansion
Correct Answer: c) Improving workability and plasticity
Rationale: Lime makes the mortar "buttery" and easier to work with, and helps it stick to
the trowel and wall.
,5. A "hawk" is a tool used for:
a) Cutting metal lath
b) Holding and carrying plaster
c) Texturing the finish coat
d) Applying the scratch coat to corners
Correct Answer: b) Holding and carrying plaster
Rationale: The plasterer holds the hawk in one hand and uses the trowel to take plaster
from it to apply to the wall.
6. What is the purpose of "beads" (corner beads) in plastering?
a) To provide a decorative edge
b) To act as a screed for plaster thickness and protect the corner
c) To create an expansion joint
d) To separate different plaster types
Correct Answer: b) To act as a screed for plaster thickness and protect the corner
Rationale: Corner beads provide a true, straight edge and a durable metal nose for
external corners.
7. Which material is most commonly used for the finish coat in a traditional NYC
interior plaster job?
a) Portland cement
b) Gauging plaster (Plaster of Paris) and lime putty
c) Fireclay
d) Acrylic stucco
Correct Answer: b) Gauging plaster (Plaster of Paris) and lime putty
Rationale: This is the traditional "gauged lime putty" finish, which hardens quickly and
provides a smooth white surface.
8. When applying portland cement plaster (stucco) on the exterior, what is the
purpose of "curing"?
, a) To make the surface white
b) To prevent the plaster from freezing
c) To retain moisture to allow the cement to properly hydrate and gain strength
d) To speed up the evaporation process
Correct Answer: c) To retain moisture to allow the cement to properly hydrate
and gain strength
Rationale: Cement requires water to cure. If it dries out too fast, it will crack and have
low strength. This is often done by misting with water.
9. What is "Plaster Weld" or similar bonding agents used for?
a) Mixing into the finish coat for color
b) Applying over dense concrete surfaces to help the scratch coat bond
c) Cleaning trowels after use
d) Waterproofing the brown coat
Correct Answer: b) Applying over dense concrete surfaces to help the scratch coat
bond
Rationale: These are acrylic bonding agents used on smooth, non-porous surfaces (like
concrete columns) where a mechanical key is insufficient.
10. "Self-furring" metal lath has dimples or indentations to:
a) Make it easier to cut
b) Create a small gap between the lath and the waterproof paper/backing
c) Add decorative texture to the wall
d) Interlock with adjacent sheets
Correct Answer: b) Create a small gap between the lath and the waterproof
paper/backing
Rationale: This "furring" space allows plaster to flow around the lath, completely
embedding it, which prevents rust and provides a stronger key.
