A cupola creates a roof-to-wall transition that must shed water continuously around its base. Inspect the curb flashing and the cupola's own walls or vents before assuming the flat roof is leaking.

What to check first

  • Trace water from the cupola walls down to the curb.
  • Inspect corners and the uphill side.
  • Confirm that the repair does not obstruct ventilation openings.

Follow the connection from top to bottom

  1. Find the upper entry point

    Inspect where flashing ends against a wall, curb, pipe, or other surface. Water entering behind that termination may bypass a patch lower down.

  2. Correct the underlying defect

    Loose metal, rotten wood, failed fasteners, and deteriorated membrane need a suitable repair before waterproofing. A surface bridge needs stable, compatible material on both sides.

  3. Keep the detail functional

    A repair should shed water without blocking outlets, weep paths, or intended movement. Use the specified reinforcement and dimensions for the product and detail.

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.

Watch Cupolas on Flat Roofs: Curb and Wall ConnectionsOpens on YouTube ↗

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.