Final answer:
The statement is true; fire-stop spacers and support boxes are necessary for safe and efficient chimney installation in factory-built fireplaces.
Step-by-step explanation:
The statement that the openings through which the chimneys of factory-built fireplaces pass should be blocked with fire-stop spacers and support boxes is true. Fire-stop spacers and support boxes are key components in a properly installed chimney system designed for factory-built fireplaces. They serve critical safety functions by preventing the spread of fire and maintaining the integrity of the fireplace and surrounding structure. Effective installation ensures that most of the heat is utilized by the wood stove or other device, rather than escaping through the chimney, increasing both safety and efficiency.
This is important because these spacers and boxes are designed to prevent the spread of fire and restrict the passage of smoke and heat into areas where they are not supposed to be. They help maintain the integrity of the building's fire safety system, ensuring that the fire remains contained within the fireplace and chimney.Without these fire-stop spacers and support boxes, there is a risk of fire spreading, which can be dangerous and can cause significant property damage.