Before conducting a sweep, all unused openings should be what?

Before conducting a chimney sweep, it is essential to ensure that all unused openings are sealed. Sealing these openings helps prevent debris and soot from escaping into the home during the cleaning process. It also helps contain potentially harmful gases and byproducts that can result from chimney operation, ensuring they do not enter the living area.

Sealing is different from simply covering or securing, as it implies creating a barrier that prevents airflow and contaminants from migrating through the system. This practice is critical for maintaining a safe environment and maximizing the efficiency of the chimney cleaning process. It ensures that all focus remains on the active areas being swept, minimizing the potential for complications during the job.