The answer to 'how often to replace roof installation' is that most roofs need to be replaced every 20-30 years, depending on the roofing material and local climate conditions. Asphalt shingle roofs typically last 15-25 years, while metal, tile, or slate roofs can last 50 years or more with proper maintenance. Regular inspections and timely repairs can extend the lifespan of your roof, but eventually all roofs will need to be replaced due to wear and tear, weather damage, or changing home needs.
It's a good idea to have your roof inspected by a professional roofer every 5-10 years to identify any issues and determine when a full roof replacement may be necessary. Signs that your roof is nearing the end of its lifespan include curling, cracked, or missing shingles, excessive granule loss, and leaks or water damage in the attic.