Posts and railings penetrate or interrupt the roof's weather barrier. A patch around a moving or poorly supported post may fail again, so the attachment and flashing need to be considered together.

What to check first

  • Inspect the post base and its movement.
  • Look for trapped water around mounting plates.
  • Keep structural fastening and waterproofing repairs distinct.

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 Leaks Around Roof Posts and RailingsOpens on YouTube ↗

From the project archive

Railing post components illustrated
Historical project photo · Flat Roof Doctor
Railing Post sleeve cover
Historical project photo · Flat Roof Doctor
Flat-roof-with-post-and-railing
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.