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Hercules-Plus® RetroDrain

Get all the benefits of the industry’s top-selling insert drain – with OMG’s exclusive vortex breaker technology built right in!

Code approved Hercules-Plus Roof Drains feature OMG’s exclusive integrated vortex breaker technology. The Hercules-Plus RetroDrain can provide up to 2.5 times greater water flow to reduce excessive water and weight from the roof faster. Hercules-Plus drains are available in 3-, 4-, 5- and 6-inch sizes, and with a TPO or PVC coated flange for direct membrane attachment.

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  • Hercules-Plus Performance Comparison Play
  • Hercules-Plus Performance Comparison (Spanish) Play
  • Hercules-Plus Vortex Strainer Installation Play

Features & Benefits

  • Water flow is up to 2.5 times faster versus the original Hercules Drains.
  • Bright yellow strainer domes are cast aluminum for strength and durability, and remain visible on the roof for improved safety.
  • U-Flow Seal exceeds the ANSI/SPRI RD1 standard for a secure, watertight connection.
  • Saves time and money by allowing easy installation from the rooftop without disturbing occupants.
  • Most OMG Hercules-Plus Drains have been certified by QAI Laboratories to conform with ASME 112.6.4 and CSA-B79-08.

Product Use

Hercules-Plus RetroDrains are designed to replace existing new construction drains in re-roofing applications. Installed from the roof surface, Hercules-Plus RetroDrains are engineered to be installed without removing the existing drain fixture. Hercules-Plus drains have 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:Yellow Vortex Breaker made of cast aluminum (5-in. height)
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

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

Hercules with TPO Coated Flange

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

Hercules with PVC Coated Flange

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

Performance Data

Flow Rate of Hercules Drains (GPM) with OMG Vortex Breaker

Head of Water (in.)3-in. Hercules Plus4-in. Hercules Plus5-in. Hercules Plus6-in. Hercules Plus