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Hercules® RetroDrain

Designed to replace existing drains in re-roofing applications and engineered to be installed from the roof surface without removing the existing drain fixture.

Code approved OMG Hercules RetroDrains, the industry’s most popular retrofit roof drains, are available in 3-, 4-, 5- and 6-inch sizes and with a variety of options to support any project, including TPO or PVC coated flange for direct membrane attachment.

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  • Hercules RetroDrain Installation Play
  • Vortex Breaker Dome Installation Play

Features & Benefits

  • Saves time and money by allowing easy installation from the rooftop without disturbing occupants.
  • Cast aluminum strainer dome and clamping ring that will not rust for long term durability and performance.
  • U-Flow Seals exceed the ANSI/SPRI RD1 (introduced in 2004) standard for a secure, watertight connection.
  • Most OMG Hercules Drains have been certified by QAI Laboratories to conform with ASME 112.6.4 and CSA-B79-08.

Product Use

Hercules RetroDrains are designed to replace existing new construction drains in re-roofing applications. Installed from the roof surface, Hercules RetroDrains are engineered to be installed without removing the existing drain fixture. The Hercules retrofit roof drain insert has a mechanical seal for direct connection to existing PVC or cast iron plumbing.

As with all building materials, it is the responsibility of the installer to review product use with a design professional to confirm safety, compatibility and acceptance with the roof cover manufacturer and local building codes.

Technical Data

Drain Body:11 gauge (.125-in.) spun aluminum
Seal:Watertight U-Flow mechanical seal (requires U-Flow screwdriver for installation)
Flange:17.5-inch diameter with sump area. TPO and PVC coated options available.
Strainer Dome:Cast aluminum, aluminum SuperDome or Vortex Breaker dome
Clamp Ring:Cast aluminum where applicable. *Not provided on TPO or PVC coated drains.


  • ASME 112.6.4 – establishes minimum design requirements for roof drains, and certified by QAI Laboratories.
  • CSA-B79-08 – Canadian Standards Association standard for commercial and residential drains and cleanouts, and certified by QAI Laboratories.
  • ANSI/SPRI RD-1 – is a national performance standard for retrofit roof drains which requires the seal to hold a 10-ft. column of water for 24 hours without leaking.

Packaging Info

Aluminum Hercules with Clamping Ring

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Hercules with TPO Coated Flange

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Hercules with PVC Coated Flange

Cat. No.Size (in)Packaging QuantityDimensional Weight (lbs)