The answer to 'signs of shingle replacement damage' is that there are several common indicators that your roof shingles need to be replaced. These include curling, cracking, or missing shingles, granule loss, and dark streaks or stains. Curled or cracked shingles are a clear sign that the shingles are deteriorating and no longer providing adequate protection for your home. Missing shingles leave your roof vulnerable to leaks and water damage. Granule loss, where the protective granules on the shingle surface wear away, is another red flag. Dark streaks or stains on the shingles can indicate algae growth or other damage.
If you notice any of these issues, it's best to have a professional roofing contractor inspect your roof to determine the extent of the damage and recommend the appropriate repair or replacement solution.