A chimney leak may start at the crown, masonry joints, cap, or roof flashing. Treating all four as the same problem can leave the actual water-entry point untouched.

What to check first

  • Look for cracks at the crown and open mortar joints.
  • Inspect step flashing, base flashing, and counterflashing as separate components.
  • Use a suitable masonry repair for damaged joints and a compatible roof repair for a confirmed flashing defect.

Inspect masonry and roof flashing separately

  1. Start above the roof line

    The cap, crown, brickwork, and mortar joints are possible entry paths. A surface coating cannot restore loose masonry or a damaged structural component.

  2. Inspect the flashing layers

    Look at the base connection to the roof and the counterflashing that protects it above. Repairing a lower seam will not stop water entering behind an open upper termination.

  3. Match the material to the defect

    Use appropriate masonry repairs for failed mortar or crown damage. For a confirmed roof-flashing defect, verify the exposed materials and current product compatibility before applying a reinforced repair.

Watch the field examples

These archive demonstrations show individual projects. Use the current guidance above and Bergstrom’s published instructions if an older video shows a different product or method. Torch work shown in installation videos is professional work.

From the project archive

Field stone chimneys with the crown and mortar joints cracked are very hard to accomplish
Historical project photo · Flat Roof Doctor
The cement slab at the top of the separated from the bricks - this is where water seeps in
Chimney leak repair on crowns
Historical project photo · Flat Roof Doctor
The stucco was cracked and therefore let water in
Historical project photo · Flat Roof Doctor

Product reference: Bergstrom Industries’ published knowledge catalog. Follow the latest product label and safety information. Historical project examples are educational and are not a specification for every roof.