Stop the leakbefore the tear-out.

Flat roofs, long cooling seasons, and sudden storms all push water at the same places: water heaters, washing-machine hoses, dishwasher and ice-maker lines, window walls, and roofs that were fine until one storm. Bathrooms and kitchens hide the slow leaks behind cabinets.

Twice a year, look at the things that move water and the things that are supposed to keep it out. You do not need a tool kit. You need a flashlight and ten quiet minutes.

• Supply lines at the toilets, sinks, washer, dishwasher, and refrigerator. Look for corrosion, bulging, and crusty white residue.
• The water-heater pan and the drain it is supposed to use. A pan full of water is already a leak.
• Under-sink cabinets and the floor in front of the dishwasher. Swollen particle board is a record of a leak, not a stain.
• Gutter outlets, downspouts, and the ground next to the foundation. Water should leave the house, not sit against it.
• Attic and ceiling stains after a hard rain, especially under roof penetrations and valleys.

Braided stainless supply lines cost little compared with a flooded room, and rubber hoses on washers are a common failure. If a line is original to an old appliance, replace it when you replace the appliance, or sooner if it feels stiff or looks stained.

Know where the main shutoff is, and make sure it actually turns. In a burst, the useful move is stopping the water, then getting out of standing water if outlets or the panel may be wet.

Shut the supply off if you can do it without stepping through standing water near power. Move what you can save. Photograph the source and the damage before anything is thrown away. Then get the structure dried. Fans from the hall closet are not a substitute for finding moisture in the wall or under the floor.

If the water came from a sudden break or a storm, call your insurer and a restoration crew the same day. The longer gypsum, insulation, and wood stay wet, the more of the room has to come out.