How to Find a Roof Leak (Step-By-Step)

Step 1: Start in the Attic

During or right after a rain, head up with a flashlight. Look for:

• Water trails on rafters or decking
• Wet or matted insulation
• Dark staining on wood
• Active dripping
• Daylight visible through the roof deck

Step 2: Trace Uphill

Water doesn't enter where it lands. It travels along rafters and decking until it hits a seam or low point and drips. Find the wettest spot, then trace the water trail back uphill until it stops. That's your entry point — or close to it.

Step 3: Mark the Spot

Push a wire, nail, or marker through the roof deck at the suspected entry point so you can find the location from the outside. Or measure from a reference like a vent pipe, chimney, or hip line.

Step 4: Look at That Spot from the Roof

Now you know where to look. Inspect that exact area for:

• Cracked or missing pipe boots — the rubber gasket around plumbing vents
• Lifted or torn shingles — usually from wind or hail
• Failed flashing at chimneys, walls, or skylights
• Cracked sealant at penetrations
• Valley issues — torn underlayment, missing shingle interlace

Step 5: Repair or Call a Pro

A cracked pipe boot or single missing shingle is a straightforward fix. Multiple lifted shingles, failed valley flashing, or chimney leaks usually need a professional. Either way, get it fixed before the next storm — small leaks turn into rotted decking and ceiling replacement fast.

Need help? WB Roofing handles roof repair across North Dallas — same-day for active leaks. For active emergencies, see our emergency roof repair page.