A strainer reduces the chance of larger debris entering the drain, but leaves can build up around it and restrict flow. Include the strainer and surrounding roof area in a maintenance plan.

What to check first

  • Check that the cover is not missing or displaced.
  • Keep debris from forming a ring around the inlet.
  • Investigate recurring backup or ponding instead of simply changing the cover.

Separate a leak from a drainage problem

  1. Trace the water route

    Follow water from the roof surface through the inlet and toward the discharge point. Inspect normal drainage and any separate overflow provision.

  2. Check the waterproof connection

    A sound pipe does not prove the membrane-to-drain connection is sound. Look for loose components, separation, damaged flashing, or patch buildup around the inlet.

  3. Preserve the opening

    A compatible local repair must not reduce the effective outlet or cover its strainer. Persistent ponding, backup, or changes to drain location and size need building-specific professional assessment.

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 A Roof Drain Strainer Still Needs Maintenance · example 1Opens on YouTube ↗Watch A Roof Drain Strainer Still Needs Maintenance · example 2Opens on YouTube ↗

From the project archive

This is a cast iron flat roof drain strainer. This was a badly designed drain strainer due to the small openings
Historical project photo · Flat Roof Doctor
Cast Iron flat roof drain strainers were not a good design
Historical project photo · Flat Roof Doctor
Plastic flat roof drain strainers don
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.