Heavy Duty PVC Coated AlumaWeld RetroDrain

The one-piece spun aluminum body has a plastisol coated flange for direct hot air welding of PVC type roof membranes. The drain flange has a depressed sump area to facilitate the easy drainage of all water from the roof surface.  The drain is equipped with a heavy duty cast aluminum strainer dome for strength and durability. The Heavy Duty AlumaWeld RetroDrain incorporates the technology of the U-Flow® Seal technology providing a mechanical watertight connection to PVC or cast iron pipes. Also available with a plastic strainer dome, in 3-in., 4-in., 5-in., and 6-in. sizes.

Features & Benefits

  • One-piece seamless body manufactured from 0.125-in., 11 gauge spun aluminum.
  • Extra large 17 1/2-in., plastisol coated flange.
  • Sump area.
  • Flange has welded metal clips for dome attachment.
  • 12-in. long drain stem.
  • Incorporates U-Flow Seal technology for a secure, watertight connection.
  • Simple and easy to install.


For detailed drawings, click here.  For 3-Part Specifications, click here.

Ordering Info
Downloads & Videos


OlyFlow® RetroDrains are designed to replace existing drains in re-roofing applications. Installed from the roof surface, OlyFlow RetroDrains are engineered to be installed without removing the existing plumbing or fixture while providing a watertight connection to the roof system and the existing plumbing.

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


Ordering Information

SKUSize (in.)PackagingWeight (lbs.)
HDPVC3A 3 Each 32
HDPVC4A 4 Each 32
HDPVC5A 5 Each 32
HDPVC6A 6 Each 32


Physical Data:

The data below is constant for each Heavy Duty AlumaWeld RetroDrain.

Drain Body 11 gauge (.125-in.) spun aluminum
Seal Watertight U-Flow nechanical seal requires U-Flow screwdriver
Flange 17 1/2-in. diameter pasticol coated with sump area
Strainer Dome Cast aluminum or plastic
Stem 12-in. length

Go back

Product 5 of 24

Superior productivity. Superior performance.