your roof is what protects you and your home from the outside world. A bad roof will cause water leaks leading to damaging your home it may cause damage to drywall, insulation, any interior wood, will mold/rot plywood or roof trusses. replacing or cleaning your gutters is also very important because water will be unable to properly flush away from your home. Instead, the water will spill over the side of your gutters, leading to a number of different issues like foundation damage, structural issues, mold and rot in basement flooding.