The answer to 'how often to replace flat roof' is that most flat roofs need to be replaced every 10-20 years, depending on the materials and workmanship. Properly maintained flat roofs can last up to 25 years, but many need replacement after 15-20 years due to wear and tear from weather exposure, ponding water, and other factors. It's important to have a professional roofing contractor inspect your flat roof regularly and make any necessary repairs to extend its lifespan.
Flat roofs are more vulnerable to damage than sloped roofs, so they require more frequent inspections and maintenance. Signs that your flat roof may need replacement include leaks, cracks, blisters, or areas of ponding water. Catching and addressing these issues early can help you avoid costly roof failures and extend the life of your flat roof system.