Welcome To The Roof Drain Sump Pan Model LSP Product Page.

Product Purpose And Description

Roof drain sump pan model LSP is specifically designed to "sump",

or lower, the Zurn Z100 15" primary cast iron roof drain. The integral sump feature lowers the roof drain 2-1/2" below the flat roof deck  surface. Sumping a roof drain is vital if you want to maximize your roof drains potential and eliminate standing water on your flat roof. 

The physical drainage surface of the sump pan and the large 15" bowl diameter of the roof drain, are a powerful combination. 

The outside sump pan dimension is 32" x 32" and the sump area is 22" x 22".  The sump area adds to the large 15" bowl diameter  to create a huge drainage area.  

The roof drain alone, with it's massive 15" bowl inlet, and less the area of the sump pan, can drain up to 110 gallons per minute of rainwater and serve a roof area of 5,300 square feet. This is based on a 4" pipe at 1/4" drop per foot at 2" per hour of rainfall. (ref 2015 Uniform plumbing code.)  When you add the sump area, the drainage efficiency is increased from there. 

There are two versions of model LSP roof drain pan: the first is the standard version which accepts the bottom outlet roof drain and the second version is the modified version that accepts the side outlet roof drain. 

roof drain sump pan, model LSP

roof drain sump pan, model LSP


This versatile sump pan can be installed on a wood, metal or concrete roof without extensive modification to the roof, the sump pan or drain with the exception of model LCP. You can use both sump pan versions to accomodate you pipe direction.  

Fast and easy flat roof drain installation

This roof drain installation video shows an actual project where LSP roof drain pan "sumped", or lowered, a Zurn 15" cast iron roof drain. While the video shows the older version sump pan being installed, the new version uses the same installation procedure.  This video mainly shows the top view or the rooftop view. 

Once installed, the ponding rainwater was completely eliminated. While the video shows a professional plumber, this drain system can be installed by the novice and professional alike. 

Bottom View

Here is an example of what model LSP roof drain pan looks like installed from the bottom side of the roof.  FAST and EASY.  

Since you watched the videos, here is more technical info

"Standard" sump pan


 “standard” version accepts the bottom outlet Z100 flat roof drain only. 


"Modified" sump pan


 the “modified” LSP roof drain sump pan version accepts the Z100-90 side outlet roof drain.  


Zurn Z100 Roof Drain

Zurn roof drain, flat roof drain, roof drain

This bottom outlet, no-hub connection roof drain fits the LSP sump pan-standard perfectly without modification.  It is available in pipe sizes 2' - 8". 


FAST and EASY Installation

roof drain installation, flat roof drain, roof drain pan

The video covers this fully but if you still have questions, below is a link for written instruction that go beyond the video demonstration. Review the link below. 

How To Install

Space Requirements

Plumber installing a roof drain with roof drain sump pan model LSP

 This sketch will show you how much space is needed between your roof and ceiling. From this information, you can determine whether to use a bottom or side outlet roof drain.  

Space Required sketch

Ok,you got thru the tech stuff. Here is the pricing section

LSP Saver Packs - standard

Superior grade roof drain sump pan model LSP

BASELINE Price $162.75        

This standard roof drain pan accepts the bottom outlet Zurn Z-100 roof drain up to 8" pipe size only.   


  • ONE PACK: Save  $10.00
  • TWO PACK: Save  $35.00
  • THREE PACK: Save $52.50
  • FOUR  PACK: Save  $70.00
  • FIVE  PACK: Save  $87.50
  • SIX  PACK: Save  $105.00
  • TEN PACK: SAVE $100.00 on the bundle plus FREE SHIPPING
  • Please call Toll Free 888 900-9145 or 949 297-8689. 8 am - 5 pm PST to place an order or visit our shopping cart...



LSP Super Saver Packs-standard


Baseline Price $375.25

Includes the galvanized steel roof drain pan(s), 2", 3" or 4" bottom outlet no-hub cast iron roof drain(s) and hardware. 

 Compond Savings - DISCOUNT PACKS

  • ONE PACK: Save $10.00 + $39.50 bulk discount
  • 2 PACK: Save $35.00 + $79.00 bulk discount
  • 3 PACK:  Save $52.50 + $118.50 bulk discount
  • 4  PACK: Save  $70.00 + $158.00 bulk discount*
  • 5  PACK: Save $87.50 + $197.50 bulk discount*
  • 6  PACK: Save $105.00 + $237.00 bulk discount*
  • TEN PACK: SAVE $100.00 on the bundle plus FREE SHIPPING
  • Please call Toll Free 888 900-9145 or 949 297-8689. 8 am - 5 pm PST to place an order or visit our shopping cart...
  • Need a 30 pack or more? Call for a quote.

Your savings may pay for your shipping costs!


LSP Saver Packs - modified



This modified roof drain pan accepts the side outlet Zurn roof drain up to 8" only.    

This roof drain sump pan is a special order.  

Please send an e-mail with the particulars or call for a quote. 



roof drain installation, roof drain sump pan

Roof Drain Pans company is totally committed to making sure you get the RIGHT products for your job. 

To this end we have the "call the plumber" toll free hotline for questions and technical help. FREE!  

Feel free to contact by phone or e-mail 

888 900-9145.  Pacific time, USA 

Wholesalers...Call for industry rates

Contact Us

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Better yet, see us in person!

We love our customers, so feel free to visit during normal business hours.

Roof Drain Pans Company

26212 Dimension Dr. Suite 210, Lake Forest, CA. 92630

FREE tech and order support 888 900-9145. Tel 949 297-8689.