8 critical home repairs you can't ignore

Broken pipe

You know you've got a problem when: A discolored spot on a wall or ceiling grows into a dripping bulge.

What causes it? Cracks in old pipes and joints.

The worst that can happen: A flood that ruins drywall, insulation, carpets, furniture and belongings. (And remember, this isn't necessarily fresh water. It could be wastewater headed for the sewage system.)

Fix it yourself? You'll need to be pretty handy with a wrench and propane torch. But the one thing that you'll absolutely have to do is turn off the main water valve to your home until you can isolate the leak.

Who should you call? A plumber.