While you're busy defending your foundation against water damage, don't forget about the roof. Just like the foundation, it is highly susceptible to leaks, rotting or worse. Lost shingles and spot leaks are easy enough to fix for a few hundred dollars, but if the damage is too extensive — or dangerous — you might have to replace the entire roof. That could run you between $3,000 and $12,000, plus the cost of removing the old roofing materials and fixing any damage to the interior of the home [source: HomeAdvisor].
Again, prevention and regular maintenance are key to avoiding costly roof repairs. Make a careful review of your roof at least twice a year, perhaps while you're up there cleaning the gutters. Look for missing shingles, tears and other damage. Also pay close attention to the flashing around the chimney and exhaust vents. Flashing is a metal or plastic sheeting that provides a watertight seal over the cracks between the chimney and the roof surface. If sections of flashing are missing or damaged, they need to be replaced immediately.
If you have an unfinished attic, carefully inspect the wood panels directly under the roof for signs of moisture, mold, algae or active leaks [source: Kirchheimer]. If you have a finished attic, look for signs of water seepage like bubbled paint on the walls or stains on the ceiling. It's better to pay for a quick repair than to let a slow leak turn into a total nightmare.