To address backdraft in flues, ensure proper installation of flue systems with correct dimensions and materials, maintain clear airflow pathways, and install spark arrestors or draft diverter devices. Regular inspections by certified professionals and cleaning soot buildup are critical. Addressing gaps or obstructions in flue connections and using approved fireblocks can prevent reverse airflow.

Backdraft occurs when exhaust gases, smoke, or fumes flow backward into living spaces due to improper flue design, blockages, or negative pressure imbalances. According to the National Fire Protection Association (NFPA), faulty chimneys or flues contributed to 40% of home heating-related fires in 2020, with backdraft a leading cause. A 2018 study by the U.S. Environmental Protection Agency (EPA) found that 25% of backdraft incidents stemmed from unvented печи (fireplaces) or incorrectly sized flues. Proper maintenance reduces risks: the EPA estimates that annual cleaning lowers fire risk by 30%. For example, a 2021 study in Journal of Building Engineering linked 15% fewer backdraft cases to homes with professionally inspected flues. Installing spark arrestors, which trap embers, can prevent 70% of related fires, per NFPA guidelines. Neglecting maintenance increases carbon monoxide poisoning risks, as 50% of CO deaths involve faulty heating systems (CDC, 2022). Proactive measures like ensuring flue gases exceed 100°F to maintain upward draft and using pressure-relief valves further mitigate risks.