IICRC Introduction to Substrate & Floor Inspection Comprehensive Test Review 2025 (Qns & Ans).

Introduction to Substrate & Subfloor
Inspection

Comprehensive Test Review (Qns & Ans)

2025



1. Which material is considered the most stable substrate for tile
installation?
- A) Oriented Strand Board (OSB)
- B) Plywood
- C) Concrete
- D) Gypsum Board
Correct ANS: C) Concrete
Rationale: Concrete provides a solid and stable foundation
that minimizes movement and moisture issues.



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,2. What is the primary function of a vapor barrier when installed
beneath a finished floor?
- A) To provide insulation
- B) To control adhesion
- C) To prevent moisture transmission
- D) To increase structural integrity
Correct ANS: C) To prevent moisture transmission
Rationale: A vapor barrier helps to prevent moisture from
rising from the subfloor, protecting the finished floor covering.


3. Which of the following subfloor materials is least effective in
providing thermal insulation?
- A) Concrete
- B) Plywood
- C) EPS Foam
- D) OSB
Correct ANS: A) Concrete
Rationale: Concrete is dense and conducts heat, thus
providing minimal thermal insulation compared to the other
materials listed.




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, 4. When selecting a substrate for carpet installation, which factor
is prioritized?
- A) Aesthetic appeal
- B) Moisture content
- C) Load-bearing capacity
- D) Color
Correct ANS: B) Moisture content
Rationale: High moisture levels can lead to mold growth,
which is critical to address before carpet installation.


5. Which test is commonly performed to evaluate the moisture
content of a concrete slab?
- A) Calcium Chloride Test
- B) pH Test
- C) Bonding Strength Test
- D) Compression Test
Correct ANS: A) Calcium Chloride Test
Rationale: This test measures moisture vapor emissions from
the slab, essential for determining suitability for flooring.


Fill-in-the-Blank Questions


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