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Round cast iron roof drain with blue epoxy coating and plastic dome

Watts

Watts RD-104 4 in Cast Iron Roof Drain 14-1/8 in Diameter

SKU CH-8NNT-Y27N5 MPN RD-104

A 4-inch cast-iron roof drain with epoxy-coated basin and self-locking plastic dome, meeting ASME A112.6.4, IPC and UPC standards

  • Product typeDrain Components
  • Product colorBlue
  • ASME A112.6.4 and IPC/UPC compliant for code-approved installations
  • Self-locking plastic dome secures without tools for fast maintenance
  • Epoxy-coated cast iron body resists corrosion in roof environments
  • No-hub 4-inch connection fits standard pipe for simple assembly
  • Integral flashing clamp with stop ensures watertight roof seal

Roof Drain for Flat Roofs

The Watts RD-104 is a cast iron roof drain designed for flat or low-slope roofing systems. Its 4-inch nominal pipe size handles standard commercial drainage requirements. The epoxy-coated basin and grate resist corrosion from standing water and debris. This unit suits new construction or replacement projects where durable cast iron is specified.

Verify Outlet and Pipe Compatibility

Confirm the existing roof opening accepts a 14-1/8 inch overall diameter before ordering. The no-hub connection requires a separate mechanical coupling matched to your leader pipe material. Ensure the 12-1/2 inch overall height fits within the roof assembly and insulation thickness. The bottom outlet location must align with the drainage piping layout.

Cast Iron Body with Self-Locking Dome

The cast iron body provides structural rigidity and long service life under heavy roof loads. An epoxy-coated finish protects the iron surfaces from rust. The included plastic dome locks in place without tools and resists UV degradation. A flashing clamp with integral stop secures the roof membrane and prevents water migration under the flange.

How it compares

Measured against everything we stock in Drain Stoppers, Strainers & Traps, at today’s prices. Recalculated every night.

Price $236.99
Pricier than about 86% of the 4,240 comparable items (median $31.99).

Specifications

Product
Brand nameWatts
Model nameRD-104
Product typeDrain Components
Product colorBlue

Questions about this item

Does the Watts RD-104 roof drain ship with the dome and flashing clamp, or must they be purchased separately?

The RD-104 includes a self-locking plastic dome and a flashing clamp with integral stop, so no additional parts are required for a standard installation.

Which connection type and pipe size does the RD-104 use, and how do I match it to my existing plumbing?

This model uses a no-hub connection for 4-inch nominal pipe size, matching standard 4-inch cast-iron or plastic piping without hub adapters.

What does the 14-1/8-inch overall diameter mean when the drain sits on a roof deck?

The 14-1/8-inch diameter covers the epoxy-coated basin and dome, giving a wide surface area to collect water while the 12-1/2-inch overall height fits typical roof insulation thicknesses.

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