Construction Supervisor License Practice Exam

What is required for sleepers on a concrete slab that is in direct contact with earth?

1. Be fire-retardant-treated

2. Be preservative-treated

3. Have a flame spread of 75 or less

4. Be labeled with the flame spread and smoke development index

The correct answer is: Be preservative-treated

For sleepers on a concrete slab that is in direct contact with the earth, being preservative-treated is necessary because it helps protect the wood from decay and insect damage. Wood that is in direct contact with moist ground is vulnerable to deterioration; therefore, using preservative-treated wood enhances its durability and lifespan. This treatment involves applying chemical preservatives that penetrate the wood fibers, making it resistant to mold, fungus, and pests, which are particularly prevalent in areas with constant moisture or direct contact with the soil. While fire-retardant treatment can be important depending on the building codes and fire safety regulations, it is not specifically required for sleepers in this context. Requirements related to flame spread ratings and smoke development indices are also relevant to fire safety but do not directly address the primary concern of protecting wood sleepers from ground moisture. Therefore, it is crucial to treat the wood with preservatives when it is in contact with the earth to ensure its structural integrity over time.