True or False: The openings through which the chimneys of factory-built fireplaces pass should be blocked with fire-stop spacers and support boxes.

When discussing factory-built fireplaces, one crucial aspect is the proper installation and safety features regarding chimney openings. Fire-stop spacers and support boxes serve the function of preventing fire and smoke from spreading to other areas of the building through the chimney openings. These spacers are designed to fill gaps and block any potential pathways that heat or flames might use to transition from the chimney to combustible materials surrounding it.

Blocking these openings with fire-stop spacers and support boxes is essential as it helps to maintain the structural integrity of the building and ensures that the fireplace operates safely. This practice is a vital part of meeting building codes and safety regulations. The use of these components reduces the risks associated with heat transfer and can significantly decrease the likelihood of chimney fires or other related hazards. Therefore, it is true that these openings should indeed be blocked with such safety features to ensure the proper function and safety of factory-built fireplaces.