How much should the flue liner tile project above the masonry cap?

The flue liner tile should project at least 4 inches above the masonry cap because this height is necessary to ensure proper ventilation and prevent downdrafts. When the flue liner extends adequately above the chimney's crown, it facilitates the safe exit of combustion gases, reducing the risk of carbon monoxide buildup in the home and ensuring effective draft performance. Adequate projection above the cap also helps to prevent water intrusion, which can lead to deterioration of the chimney systems and the masonry itself over time. Properly installed flue liners enhance the safety and efficiency of the fireplace or heating system they serve, making compliance with this standard essential for home inspection assessments.