Why Does My Roof Valley Always Leak in Heavy Rain?

A roof valley is the inward angle where two roof slopes meet. It channels rainwater down toward the gutters. In heavy rain, that channel carries a large volume of water at once, so any flaw in the flashing or shingles becomes a weak point.

Flashing is the metal or rubber strip that lines the valley. It directs water away from the seam. When the flashing lifts, corrodes, or is missing, water can slip underneath and run down into your attic or walls. Shingles that are cut too short or nailed too tightly can also cause problems.

Start from the ground or a ladder, if it is safe. Look for visible gaps, rust, or peeling sealant along the valley. Check for debris buildup, especially after storms. Also inspect the attic for water stains or damp insulation, which can show where the leak enters.

You can also clear loose leaves from the valley with a broom or a hose, but do not walk on the roof unless you are confident. If you see cracked shingles or damaged flashing, do not try to patch it yourself. A roofer can assess the valley and recommend the right repair.

Once the rain stops, move furniture and valuables away from the wet area. Place a bucket or pan under the drip if it continues. Remove soaked carpets or rugs if you can, and run a fan or dehumidifier to speed up drying. Do not touch electrical wiring that is wet.

Inspect the attic for mold or mildew, which can develop within a couple of days. If you see mold or smell a musty odor, it is wise to have a mold professional evaluate the area. Your insurance policy may cover some water damage, but coverage depends on the cause and your policy terms. Policies vary, and your insurer decides what is covered.