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Discharge Line

A good sump pump can be invaluable when a heavy rainstorm threatens to flood your basement. But without a working discharge line, it is ineffective.

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Basements are vulnerable to flooding due to the fact they are below-grade. As such, flooding can occur at any time of year, even outside of rainy seasons. To protect your basement from floodwaters, you should install an interior drainage system and a sump pump with a functional discharge line to move water out and away from your home. 

Discharge line

What Is a Discharge Line? 

A discharge line is a plastic pipe that moves water from the sump basin out and away from your home and into the yard. It’s roughly 4” in diameter but can be 1.5” or 2” depending on the sump pump’s built-in fitting. The line usually extends 10 ft. away from the foundation or home perimeter. 

Discharge Pipe Installation 

Here’s how the installation goes: 

  •  First, the sump pump is set up properly in the sump basin; 
  • A 4″ pipe is connected to the sump pump’s discharge hole; 
  • Tiny holes are drilled on the pipe right above the pump outlet to stop airlocks; 
  • A check valve is then installed to stop backflows; 
  • An exit hole is drilled right through your basement wall or rim joist; and 
  • The pipe is extended and directed out before the area around the discharge line is sealed with caulk. 

If the drainpipe is to be buried, a sloping trench is dug and paid down then the trench is backfilled with soil. 

How It Works 

When water fills the sump pump basin, it’s the discharge line that gets it out. To work optimally, a good discharge line should be large enough to hold all the water the sump pump discharges. The contractors should bury the discharge line or extend it to your yard at a sloping angle. This allows gravity to push the water, preventing freezing. 

In cold climates, discharge lines are usually buried five inches below the frost line. Down there they can leverage the warmth of the soil around them to stay clog-free. 

Also, make sure to keep the end of the discharge line free of snow or debris that can block the flow of water. 

Benefits of a Discharge Line 

Let’s look at three reasons why you need a discharge line for your sump pump. 

Efficient Drainage 

A noteworthy benefit of a discharge line is its ability to properly drain water faster and away from your foundation. As a result, it helps you to maintain a dry basement, preventing potential foundation structural issues and water damage. 


A discharge line is surprisingly affordable when you compare it with other basement waterproofing techniques. 

Easy to Install 

It’s quite easy to install a discharge line on a sump pump. It all depends on the complexity and size of your device. 

Common Discharge Line Problems 

During the winter months, it is easy for water to stand and build up in wrongly pitched discharge lines. Extreme cold will cause the water to freeze and block the pipe. If the issue isn’t addressed, the pipe will eventually burst and this can cause a severe basement flood. That’s not to mention that your sump pump could overheat and fail as it tries to eject water via a constricted pipe.  

Discharge Line Maintenance 

Keep an eye on blockages or frozen pipes in winter. Left to freeze, the discharge line may malfunction and allow water to drain against your foundation. This is a recipe for various moisture issues around your basement. To prevent water from collecting and freezing on your discharge pipe, make sure it’s pitched at a downward angle. Also, consider shortening the pipe. 

The other thing you can do is to insulate your discharge line with heat tape. What this does is protect it from the cold. Heat tape is an affordable, heat-conducting wire that warms up the line, preventing freezing. 

Sump Pump Protection 

Finally, protect your sump pump by installing the FreezeGuard™ exterior discharge line attachment. It’s a small device with a grated adapter. Thanks to FreezeGuard™, even if the discharge line freezes, your sump pump will still be able to pump out water. You won’t have to worry about your basement. 

Worried about the condition of your discharge line or that it may freeze once the temperatures drop? Foundation Recovery Systems can help by installing the right solutions. Contact us today for a free cost estimate on updating your sump pump, its discharge line and freeze-proofing the system.

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Des Moines Location

2401 SE Creekview Dr.
Ankeny, IA 50021

Kansas City Location

7280 NW 87th Terrace, Suite C-210
Kansas City, MO 64153
(816) 774-1539

Lee's Summit Location

211 SE State Route 150
Lee's Summit, MO 64082
(816) 774-1539

Moberly Location

1401 US-24
Moberly, MO 65270
(660) 202-8662

Springfield Location
1820 N Barnes Ave
Springfield, MO 65803
(417) 612-8286
St. Louis Location

1625 Larkin Williams rd.
Fenton, MO 63026
(314) 207-9995