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LCP Roof Drain Pan Description

The model LCP pre-fabricated roof drain pan is intended to eliminate the labor and material intensive task of building a large double wood sump box while on the job. This system installs in a fraction of the time, and for construction professionals, this increases production while reducing labor costs.

  •  It’s unique design “sumps” or lowers the 15″ primary and overflow (flange dimension) bottom outlet cast iron roof drains 2″ below the deck.
  •  Is extremely effective at providing or restoring positive drainage to the flat roof, a vital necessity for ANY roof drainage system

Here are some LCP Roof Drain Pan installation applications

Model LCP roof drain pan is best suited to large commercial, industrial and institutional applications where there are large roof surface areas to be serviced

How To Use The LCP roof drain sump pan

The following information shows three types of installation methods commonly used with LCP sump pan. These apply to wood framed roofs mainly, however the pan and drains can be used on steel and concrete decks with perfect adaptability. Select the method that suits your project requirements. You can use 12" or 15" diameter roof drains with this pan.

1) Parallel Installation

As shown, the LCP sump pan is installed parallel to the joists. This method does not require any modifications. It is designed to fit between the joists that are 24″ on center minimum, but can be where the joist span is wider. It is recommended that a center brace is installed for lengthwise support and you can add end blocks if desired. The photo below illustrates this concept.  On metal or concrete roofs, it generally will not require any additional alteration. 

2) Perpendicular Installation

As shown in the photo below,  LCP sump pan is installed perpendicular or 90 degrees to the roof joists. Generally speaking, on a wood framed roof where the joists are 24″ on center, the pan would require additional framing to accommodate the sump area of the pan.  The photo below was a new construction project.

LCP sump pan

Multi-level installation

This configuration puts the primary roof drain in the sump pan and places the overflow roof drain at deck level with a drain plate. In this scenario, separate pans are used rather than a one piece, double pan.

The 2″ water dam on the overflow roof drain will be situated 2″ above the roof level rather than the bottom of the sump pan.    

The alternative is to use an LSP sump pan for the primary and a deck plate for the overflow roof drain. 

Side outlet roof drains – details coming soon

  • Disclaimer: this information is intended to be a guide only. Please evaluate your own project requirements

Jay R. Smith 1010 roof drain

Jay R Smith 1010 Roof Drain


  • Jay R. Smith 15.25″ bowl
  • Dura-Coated cast iron body
  • Combination membrane flashing clamp/gravel guard
  • Cast iron dome
  • Pipe sizes 2″ to 10″
  • Pipe sizes 2″ to 6″ fit LCP pan 
  • Get Jay R. Smith roof drain details here

Zurn Z100 roof drain:

Zurn ZC 100 primary roof drain


  • ZURN ZC100 15″ bowl diameter
  • Dura-Coated cast iron body
  • Combination membrane flashing clamp/gravel guard
  • Cast iron dome
  • Pipe sizes 2″ to 10″ 
  • Pipe sizes 2″ to 8″ fit LCP pan 
  • Get Zurn Z100 roof drain details here

LCP roof drain sump pan

  • Laser fabricated in 18 gauge galvanized or stainless steel
  • Fits between joists 24″ on center
  • Custom fabrication for stainless steel and 8″ and 10″ drains


In keeping with our intention to be an innovator in roof drain installation technology, Custom Roof Drain Pans will be adding even more to this lineup.
  • We are designing new adapters that will allow model LCP to accept bottom and side outlet 12″ primary and overflow roof drains! No modifications required. Just bolt on the adapters.   
  • New version of LCP sump pan that will accept side outlet 15″ primary and overflow roof drains! 
  • If you would like to be notified of these releases, shoot us an email with your contact info. 

Looking For Roof Drain Installation Help?

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  • Get the 8 steps that are needed to make a successful installation
  • Used by the pro’s

What are some of the benefits of using this flat roof drainage system?

list of benefits
  • Protect your roof warranty…
  • Increase jobsite production…
  • These are just a few and you can see many more by clicking below


CONSULTATION SERVICE: Send us your specs/plans/drawings.

  • We’ll review and send you an estimate
  • then arrange the phone interview
  • We’re plumbing contractors and experienced using the products

Have a basic product question or pricing?  

  • call (949) 297-8689
  • M – F, 8 am to 5 pm, PST Calif USA. 

(949) 297-8689

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