CA D-87 Waterproof Deck Coating
Contractor Exam Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a waterproof deck coating system?
A. To increase the structural capacity of the deck
B. To provide a decorative finish only
C. To prevent water intrusion while protecting the deck surface
D. To eliminate the need for proper drainage
Rationale: A waterproof deck coating system is designed primarily to
resist water penetration and protect the underlying substrate from
moisture-related deterioration. It is not intended to replace structural
repairs or correct drainage deficiencies.
2. Before applying a waterproof deck coating, what should be done
first?
,A. Apply the final topcoat
B. Flood the deck with water
C. Inspect and evaluate the substrate and existing conditions
D. Install decorative aggregate
Rationale: A thorough inspection identifies cracks, spalling, moisture
problems, loose material, improper slopes, and other conditions that
may affect coating performance. Surface preparation should be based
on these findings.
3. Why is adequate deck slope important in a waterproof coating
system?
A. It makes the coating thicker
B. It improves the color of the coating
C. It promotes drainage and reduces standing water
D. It eliminates the need for waterproofing
Rationale: Water should drain away from the deck rather than remain
on the coated surface. Persistent ponding can accelerate coating
deterioration and increase the likelihood of water intrusion.
4. Which condition can seriously interfere with adhesion of a deck
coating?
,A. Clean, dry concrete
B. Properly prepared plywood
C. Oil, grease, or other contaminants
D. Sound and properly profiled substrate
Rationale: Contaminants such as oil and grease can form a bond-
breaking layer between the substrate and coating. They must be
removed during surface preparation.
5. What is the purpose of mechanical surface preparation?
A. To increase the moisture content of concrete
B. To eliminate all expansion joints
C. To remove unsound material and create an appropriate surface
profile
D. To replace the waterproofing membrane
Rationale: Grinding, shot blasting, sanding, or other mechanical
methods can remove weak surface material and create a profile that
allows the coating to mechanically bond to the substrate.
6. What should be done with loose or delaminated concrete before
coating?
A. Cover it with additional coating
B. Paint over it with primer
, C. Remove it and repair the affected area
D. Saturate it with water
Rationale: Coating over loose or delaminated concrete does not correct
the underlying defect. Unsound material must be removed and the
substrate repaired before waterproofing.
7. Why are cracks in a deck substrate important before
waterproofing?
A. They improve coating adhesion
B. They reduce coating consumption
C. They can provide pathways for water intrusion and may reflect
through the coating
D. They eliminate the need for reinforcement
Rationale: Cracks can allow water to reach the substrate and may
continue to move after coating application. Appropriate crack repair or
treatment is therefore essential.
8. Which type of crack generally requires special evaluation because it
may indicate structural movement?
A. A superficial hairline crack in a stable finish
B. A coating discoloration
Contractor Exam Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a waterproof deck coating system?
A. To increase the structural capacity of the deck
B. To provide a decorative finish only
C. To prevent water intrusion while protecting the deck surface
D. To eliminate the need for proper drainage
Rationale: A waterproof deck coating system is designed primarily to
resist water penetration and protect the underlying substrate from
moisture-related deterioration. It is not intended to replace structural
repairs or correct drainage deficiencies.
2. Before applying a waterproof deck coating, what should be done
first?
,A. Apply the final topcoat
B. Flood the deck with water
C. Inspect and evaluate the substrate and existing conditions
D. Install decorative aggregate
Rationale: A thorough inspection identifies cracks, spalling, moisture
problems, loose material, improper slopes, and other conditions that
may affect coating performance. Surface preparation should be based
on these findings.
3. Why is adequate deck slope important in a waterproof coating
system?
A. It makes the coating thicker
B. It improves the color of the coating
C. It promotes drainage and reduces standing water
D. It eliminates the need for waterproofing
Rationale: Water should drain away from the deck rather than remain
on the coated surface. Persistent ponding can accelerate coating
deterioration and increase the likelihood of water intrusion.
4. Which condition can seriously interfere with adhesion of a deck
coating?
,A. Clean, dry concrete
B. Properly prepared plywood
C. Oil, grease, or other contaminants
D. Sound and properly profiled substrate
Rationale: Contaminants such as oil and grease can form a bond-
breaking layer between the substrate and coating. They must be
removed during surface preparation.
5. What is the purpose of mechanical surface preparation?
A. To increase the moisture content of concrete
B. To eliminate all expansion joints
C. To remove unsound material and create an appropriate surface
profile
D. To replace the waterproofing membrane
Rationale: Grinding, shot blasting, sanding, or other mechanical
methods can remove weak surface material and create a profile that
allows the coating to mechanically bond to the substrate.
6. What should be done with loose or delaminated concrete before
coating?
A. Cover it with additional coating
B. Paint over it with primer
, C. Remove it and repair the affected area
D. Saturate it with water
Rationale: Coating over loose or delaminated concrete does not correct
the underlying defect. Unsound material must be removed and the
substrate repaired before waterproofing.
7. Why are cracks in a deck substrate important before
waterproofing?
A. They improve coating adhesion
B. They reduce coating consumption
C. They can provide pathways for water intrusion and may reflect
through the coating
D. They eliminate the need for reinforcement
Rationale: Cracks can allow water to reach the substrate and may
continue to move after coating application. Appropriate crack repair or
treatment is therefore essential.
8. Which type of crack generally requires special evaluation because it
may indicate structural movement?
A. A superficial hairline crack in a stable finish
B. A coating discoloration
