The answer to 'when to replace roof vent' is that roof vents should typically be replaced every 10-15 years or when they show signs of damage or deterioration. Roof vents play a critical role in maintaining proper airflow and ventilation in your home, so it's important to keep them in good working condition.
Common signs that it's time to replace a roof vent include cracked, warped, or damaged flashing, rusted or corroded metal, and deteriorating seals around the vent. If you notice any of these issues, it's best to have a professional roofing contractor inspect the vent and recommend replacement if needed.