How to tell if roof leak is from chimney or shingles?

# Identifying the Source of Your Roof Leak

Look for water stains and damage patterns. Water from a chimney leak typically appears on the interior walls adjacent to the chimney or directly below it inside your attic. Shingle leaks usually show up in a broader area, often in lines or patterns where water runs down the roof. Check your attic during or after rain to see exactly where water is entering—this is your best clue.

Inspect the chimney flashing. Chimney leaks almost always originate from failed flashing—the metal seal where the chimney meets the roof. Look for rust, cracks, gaps, or separation. You might also notice deteriorated mortar or brick around the base of the chimney. If the flashing looks compromised, that's likely your culprit.

Examine the shingles near the leak. Look for missing, cracked, curled, or bald shingles in the area above the water stain. Also check for nail holes, holes from debris, or signs of age/weathering. If shingles look intact but you see water penetration, the issue might be deteriorated underlayment beneath them.

The location matters too. Leaks appearing near the roof peak or ridgeline are usually shingle-related. Leaks confined to one wall section near your chimney suggest chimney flashing failure.

Quick tip: Sometimes it's both—older roofs may have multiple issues. A professional roofer can definitively diagnose the source with a thorough inspection. They can also check for water damage behind walls that you can't see, which is important for assessing repair costs.

If you're not comfortable climbing on the roof yourself, it's worth getting a contractor to inspect it. Many offer free estimates and can identify the exact problem so you know what repairs are needed.