Book a Consultation

Prevent A Frozen Sump Pump Discharge Line In Three Steps

Snowy field with trees

The purpose of a sump pump, of course, is to expel any rainwater that seeps into your home.  You may hope that water intrusion is less of an issue in the winter months, but that’s rarely the case.  Instead of rain, you’re dealing with melted snow (although we get our share of winter rains, too).

Here in the midwest, we often experience a cycle of freeze, thaw, and re-freeze.  And these temperature fluctuations can cause water lines to freeze and back up. You’re probably already familiar with the concept of letting a faucet drip to keep your water pipes from freezing.  But how do you avoid ice forming in a drainage line outside?

Acculevel has been waterproofing basements and crawl spaces since 1996, and we have installed thousands of water drainage systems.  We’re going to review the best practices of running a discharge line to help you prevent a common winter issue: a frozen drainage line.

What Happens if the Drainage Line Freezes?

When you install a sump pump, you also run a discharge line from the pump to the outside.  This line is what drains the water away from your home. If the drainage line freezes, the ice in it will block water from draining.  That drainage then builds up, collecting in your basement or crawl space and around the foundation. Without the ability to discharge the water, your sump pump cannot run continuously.  Eventually, the pump will be overwhelmed and burn out, the space will flood, and you find yourself in the exact situation you were trying to prevent.  

How to Install a Sump Pump Discharge Line

Three Steps To Follow To Prevent Freezing

  1. Use a sturdy PVC pipe. You will need to make certain the drainage line is free of dips and curves (no high or low points), as these can interfere with the natural flow of water. It’s this natural flow that allows the pipe to completely drain, even after the pump turns off.  Low points will create ‘pockets’ that can hold water and allow it to freeze. In our experience, the best way to do this is to use a 2 inch diameter pipe. Most sump pumps only require a 1 ½ inch pipe, but a larger pipe is more rigid and less like to compress or allow any dips to form. 
  1. Verify the grading slopes properly. The ground around your foundation should slope down and away from the foundation.  This is the easiest- and most natural- way to direct water flow in the right direction.  This is important for two reasons. First, because a good slope helps the water drain completely out of the line.  Second, the slope will encourage the water to continue draining away after it leaves the pipe.  You don’t want the water freezing inside the line, nor do you want it freezing just outside the line.  Either instance will block the drainage from leaving your home.

pop up drain

A typical pop-up drain

  1. Install a pop up drain in the yard. At the end of your drainage line, attach a pop up drain.  At Acculevel, we also drill three ½ inch holes in the bottom of the pop-up pipe as part of our installation process.  We then set the pop up drain into a small pit filled with five gallons of pea gravel. These extra holes help drain any water that might collect at the bottom, and having the water release into gravel helps disperse it more gradually.  All of this makes the water less likely to form puddles or (in warmer weather) wash out your soil.


Things to Avoid When Installing a Sump Pump Discharge Line

We Do Not Recommend Freeze Guards

A word of caution: some contractors will install a freeze guard, but this is not something we do, nor do we advise you to do it.  Freeze guards are overflow devices that attach to the drainage line as it exits the foundation.  It’s true that these allow water to escape if your drainage line freezes; but if this happens, the water will be released directly next to the foundation.  

The purpose of a drainage line is to move the water away from your home, because otherwise, it will pool around the foundation and seep back into your basement or crawl space. This cycle will keep the sump pump running continuously, processing the same water over and over without the ability to properly discharge the water at a safe distance.  Eventually, the pump will be overwhelmed and burn out, the space will flood, and… and this sounds… oddly familiar… probably because this is what we’re trying to prevent!

The Drainage Line Should Not Be Near Your House 

We recommend that a drainage line be at least 20 feet from your foundation; 10 feet is the absolute minimum.  In general terms, the farther away the better- but like in most things, moderation is key.  If your drainage line is 100 feet or longer, it will require the sump pump to work harder and shorten the life of the pump motor.

Misconception: A Sump Pump Discharge Line Needs to be Buried Deep

Some homeowners mistakenly think that the drainage line needs to be buried several feet down, below the frost line.  This confusion is understandable; after all, we used the concept of ‘let the faucet drip’ at the beginning of this article as an example of good preventative measures.  

But there’s a key difference between the water pipes running inside your home (used for drinking water) and a drainage line outside your home.  The water lines inside your home need to be buried deeper underground because they hold water all the time. They have to, because when you turn on the tap, you expect water to flow immediately.

On the other hand, a properly installed discharge line only has water in it while the sump pump is running.  When the pump expels the water from your home, it’s at a warmer temperature than the soil outside, and it’s moving quickly.  This, combined with a good slope and well-installed drainage line, should be enough to keep it from freezing before it’s cleared the drainage area.


Learn More About Water Drainage For Your Home

Do you have more questions about the components of water drainage?  We have more to share on our blog, where we cover the other details of waterproofing basements and crawl spaces.  

Do you think water is causing problems with your foundation?  Maybe you’re not sure what the problem is, but you’ve noticed some issues around your house.  If so, use our free tool for homeowners that walks you through different symptoms and possible solutions.

 link to symptom checker

If you need professional advice, find an experienced local foundation company and make an appointment. Before you sign a contract for any service, you should always verify the company is reputable, insured, and accredited by the Better Business Bureau.

If you live in Indiana or the surrounding states, contact Acculevel!  We will schedule an estimate for you with one of our experienced project managers. They will evaluate your home and recommend the best course of action for you, to keep your home strong and healthy for years to come.




Kelly Kater

Over her twenty year career, Kelly has worked in a wide variety of fields: secondary education, nursing, biology, elder care, the postal service, multicultural development, and academia. She has developed a skill for translating industry-specific jargon into everyday language. Her goal is to share the knowledge and experience of the Acculevel team with homeowners, in a way that is both engaging and informative.

Get Started

Please enter your first name.
Please enter your last name.
Please enter your phone number including the area code.
Please enter your email address.
Please select the type of request.
Sending now...

    Stay In Touch

    Get Email Updates

    Sign up for email notifications about new articles.