Frank Pattern 850-SN Combination Drain Kit


Frank Pattern 850-SN Combination Drain Kit includes: double roof drain sump pan, (2) side outlet, single roof drains, (1) flat plate adapter, (1) water dam, (2) hardware kits and (2) standard grade no-hub couplings.

  • Specialty no-hub couplings are available as an upgrade. See the description below.

  • Shipping to the Continental US, Hawaii, Alaska and Canada,


Frank Pattern 850-SN Combination Drain Kit is intended to be used when installation space is at a minimum between the roof and ceiling and a side outlet roof drain is required. 

It is ideally suited for residential and light commercial applications. It is very quickly assembled and installed and it will eliminate the need to build a wood sump pan on the job. A huge time saver!

SCPM Roof Drain Pan

It is the modified version of SCP roof drain pan

The roof drains for model SCPM roof drain pan are installed opposing each other so the pipe runs are in opposite directions. Very soon, the roof drains will be adjustable to any direction and will accept multiple manufacturer brands.

  • It is modified to accept two side outlet single small Frank Pattern brand roof drains with our patent pending adapter plate.
  • The sump pan’s dimensions are 34-1/2″ L x 26″ W x 2″ deep
  • The flange dimensions are 6.271″ on each side
  • It is fabricated from stout 18 gauge galvanized steel on modern laser fabrication machines. The quality manufacturing results in a perfect fit every time!

Frank Pattern 850-SN Combination Roof Drain

  • The Frank Pattern brand side out roof drain has an 8-1/2″ diameter bowl.
  • It is available in 2″-4″ bottom outlet, no-hub pipe sizes
  • Each roof drain has a cast iron membrane clamp (flashing ring) which compresses the membrane and makes a water tight seal.
  • Each roof drain has a dome or leaf grate that prevents debris from entering the roof drain. It twist locks into the membrane clamp. It is 5-1/2″ high.

Water Dam

  • The 2″ water dam (shown) is bolted to one of the primary roof drains.
  • It replaces one of the two membrane clamps on the roof drains.
  • This converts it into an externally mounted overflow roof drain.
  • This complies with the current Uniform plumbing code.

Flat Plate Adaptor

    • The flat plate adaptor converts the sump pan so it will accept side outlet roof drains rather than the combination bottom outlet roof drain.
    • It is quickly bolted to the sump pan with four bolts.
    • The adapter plate dimensions are 19″ x 10.53.
    • It is engineered to be bolted to the sump pan and accept the side outlet roof drains.
    • It is fabricated from stout 18 gauge galvanized steel
    • Flat Plate Adaptor

Hardware Kit

  • Your hardware kit bolts the roof drain to the sump pan with four bolts.
  • This is an extremely solid connection and will never fail once correctly assembled.
  • This kit is free with your purchase.

No-Hub Couplings – standard grade

  • standard grade no-hub couplings are intended to be used to join cast iron to cast iron parts, whether pipe or fittings.
  • The couplings are FREE WITH YOUR PURCHASE.



    • Higher grades of galvanized steel, stainless steel and aluminum.
    • Powder coating, painting or rubberized undercoating
    • Via special order.


  • If you will be using plastic or steel pipe, it is recommended to use specialized couplings as they transition from cast iron (on the roof drain) to plastic or steel pipe.
  • The standard grade no hub coupling joins cast iron to cast iron and is included in your kit.


Are You Looking For Frank Pattern 850-SN Combination Drain Kit installation Info? 

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SCP installation kit
SCP roof drain pan

Additional information

Weight 50 lbs
Dimensions 32 × 32 × 12 in


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