How do you find a roof leak?

Water travels, so the drip inside is often downhill from the real entry point. Start in the attic during or after rain with a flashlight: trace the wet path up the decking and rafters to the highest point of moisture, which is usually near the actual hole. Mark it, then locate the matching spot on the roof outside.

On the roof, check the usual suspects first: flashing around chimneys, vents, and skylights, cracked pipe boots, and damaged or missing shingles. A garden-hose test, wetting one small area at a time while someone watches inside, isolates a stubborn leak.

If you cannot safely get on the roof or into the attic, a roofer with moisture-meter and infrared tools can pinpoint it.