Yes, it is common for roofs with missing or broken shingles to take up to three years before leaks can be seen inside. In some cases the leak gets behind the walls and creates mold and mildew. Many Jacksonville, FL roofing contractors will just replace the missing shingles which is a temporary fix. Call StormForce for a comprehensive roof inspection and report before you make the mistake of patching a roof that is severely damaged or that has exceeded its useful life.