How to Install a Sump Pump and Sump Pit System

Anyone who has a basement sump pump understands the importance of proper sump functionality to keeping a basement unit free from flooding.The sump pump is simply a pump that moves accumulated groundwater out of the home. They are usually installed in basements or crawl spaces and reside in sump pits.

A Goulds Submersible Sump Pump
Goulds STS21V submersible sump pump

Sump pumps are necessary for homes that sit above a high water table or have frequent basement flooding issues. When groundwater starts to accumulate underneath the home, it will inevitably rise and put pressure on the concrete floor. Digging a sump pit in the earth gives the groundwater another path to travel, the path of least resistance. As the water moves into the sump pit, the sump pump ejects that water out of the home.

You may know that your home basement has a slight flooding problem but what if you do not know how to install a sump pump or sump pit? This blog will walk you through the process step-by-step.

The Step-by-Step Sump Pump Installation Walkthrough

Locating the Installation Site and Creating the Pit

First, gather your materials and tools, including the sump pump itself and a basin.

A wide variety of sump pump types are available. We recommend buying a submersible sump pump with a perforated basin that includes suction inlets on the side. You will need at least 18 inches minimum diameter basin for a single sump pump. You might want to consider buying a complete sump pump package with accessories to  avoid tracking down the extensive list of materials you will need.

Next select the corner or section of your basement where you want to install the sump pit. Consider these factors when choosing where to place your sump pit:

1) Proximity to the rim joist. The pit should be as close as possible to the outer joist.
2) Elevation. Try to find the lowest point – if your basement is already prone to flooding, just see where the water tends to collect.
3) Try to stay at least 8 to 12 inches away from the wall; remember that you will be digging into the ground and there is a concrete footer underneath your wall’s cinder blocks. The footer should not be touched – it is the house’s foundation.
4) Proximity to a power source. Plug the pump directly into an outlet for best usage.

Also, be sure to call 811 at least two to three days before you start to dig. 811 is a free national service that will provide information on the location of utility lines. You do not want to start digging and damage your water line or other underground utilities.

Once you have the area mapped out, you will need to size the pit. First, trace the outer edges of the basin top, then add 6 to 12 inches around that line to determine the total circumference of your pit. The extra space will be filled by gravel.

Now it is time to actually cut into the concrete floor. If you are using a sledgehammer, bore a hole every 4 inches with a hammer drill and then start hammering. You can also use a jackhammer, concrete demolition saw or masonry chisel.

After you have sufficiently cut the concrete, remove the concrete pieces until you see your dirt floor. Start digging. For depth, reference the basin height and add 6 to 12 inches. Fill the pit with 6 to 12 inches of gravel. Before installing the basin, we recommend wrapping it in filter fabric or landscaping fabric. The fabric protects the basin from dirt, grime and other particulates from entering the basin and ensures proper pump functioning. Insert the basin.

Discharge Piping and the Check Valve

Cut the vertical riser pipe so that it sticks at least 1 foot out of the basin and attach it to the pump’s discharge outlet. Most homes will use schedule 40 PVC pipe with a 1-1/2 inch discharge size. If you are using PVC, we recommend you clean the pipe with PVC primer before applying PVC glue to any pipe fittings (if there is accumulated dirt on the pipe, the glue may not adhere). Bind the power cord to the pipe using vinyl tape or zip ties. 

An important part of the discharge pipe is the weeping hole or vent hole. The weeping hole is a 1/8 to 1/4 inch hole drilled horizontally into the discharge pipe. The weeping hole allows compressed air that has been sucked into the pump to escape, thus preventing air bounding. Critically, make sure to drill the weeping hole above the discharge outlet of the pump, below the check valve and well before the basin top so that water does not splash out of the hole.

Now you are ready to attach the check valve to the discharge pipe. The check valve is a valve that contains a single-hinged flap that can only open in one direction, preventing backflow. When pumped water flows back down the pipe and back into the pump, the sump pump will continuously start and stop, a surefire recipe for burnout and pump failure.

Connect the check valve to the discharge pipe. Experts recommend installing a check valve with some kind of quick disconnecting coupling on either side of the valve, known as a fernco, no hub or slip joint. If you ever need to perform maintenance, you can simply disconnect the coupling as opposed to cutting into the pipe.

Finally, connect another vertical riser pipe to the other side of the check valve.

Putting the Sump Pump in the Basin

Put the sump pump in the basin, preferably on top of a paver or stand that will shield the pump from any debris or muck that accumulates on the floor of the basin. Place the basin lid over the basin. Depending on what type of basin you buy, you may have to bore a hole for the discharge pipe on the lid.

Also make sure there is enough space between the pump itself and the basin wall for the float switch to operate – we recommend a mechanical switch.

Presto. You have created a sump pit and successfully installed a sump pump with discharge pipe and check valve attached. Now you need to consider where to pump the excess water.

Where Does the Water from My Sump Pump Go?

Outside, obviously. Remember when we told you to place the pit close to the rim joist? Drilling through the rim joist is probably the easiest way to have the piping exit the home. Drill a quarter-inch hole through the joist at a point directly above the pit. Next, go outside and locate the quarter-inch hole. Use a 2 inch bit to drill back through the original hole.

Insert a PVC pipe horizontally through the hole, long enough to exit the house. Go back inside the basement and attach a 90 degree elbow to the horizontal pipe you just inserted. The elbow should point down and align with the sump pump’s vertical riser pipe. Measure, mark and cut the vertical riser pipe so that it sits plum with the elbow.

The inside of the system should be set. Go back outside and install another 90 degree elbow to the horizontal pipe. Finally, seal the space where the horizontal pipe goes through the rim joist with high grade weatherproof silicon caulking to minimize vibrations in the pipe caused by the pump running.

Directing the Water

At this point, directing the piping depends on your property’s configuration. The most obvious solution is to eject the water directly from the pipe into the backyard or bushes. Be warned: water deposited directly outside the house will travel through the ground and start seeping through the basement walls. Place a sloped splash pad or block right under the discharge pipe to direct the water as far as possible from the home and foundation.

Municipalities across the United States have cracked down on the practice of directing this water into street catch basins to avoid the cost of recycling private water and overloading the public system. In addition, water runoff in the streets tends to freeze in cold climate areas. Attempting to run the sump pump into the city sanitary sewer line is highly illegal and could result in heavy fines.

If you have the space and means, we recommend installing a leaching tank in your backyard. A leaching tank is simply a repository tank that sits at a distance from the house and collects runoff. The leaching tank gradually distributes the collected water throughout the ground.

The Backup Plan

-Zoeller 508-0006 Sump Pump Package

Since sump pumps prevent flooding, and flooding and power outages often go hand-in-hand, many homeowners choose to have backup sump pumps for added peace of mind. Battery backup sump pumps are the most common types – they run automatically during a power outage. Battery backups can also operate if the water level is too much for the primary sump pump.

Another backup option that does not require electricity is a water powered sump pump. The water powered sump pump only turns on when the primary sump pump fails and water rises, exceeding a certain level.

Furthermore, if you decide to purchase a backup sump pump, keep in mind that the size and configuration of the sump pit will need to change. Additional piping or hosing and pipe fittings will also need to be purchased. This diagram from Goulds gives you a picture of how a typical sump pit with a battery backup is configured.

Flooding is a very real problem that disrupts the lives of many homeowners. You might want to consider buying a complete battery backup system to dispel any worries and have everything you need on hand in one convenient package.

The French (Drain) Connection

The French drain is a trench system that collects the water that seeps through the basement walls and collects on the floor. The drain uses perforated piping to direct the water to a specific point, namely the sump pit. Installing the French drain system can be costly and time-consuming, but if you are particularly worried about groundwater damaging the foundation of your house, this system could be a possible solution.

Here is a basic primer on installing a French drain:

–Cut and remove the concrete slab at least a foot from the wall.
–Dig a trench lining at least 6 to 12 inches below the footing.
–Fill in 6 to 12 inches of gravel.
–Place perforated PVC pipe above the first layer of gravel
–Fill the trench with another 6 to 12 inches of gravel, surrounding the piping.
–Place a filter cloth or membrane on top of the top layer of gravel.
–Re-fill the trench then compact soil on top of the filter membrane.
–Put a 1-and-a-half inch wooden board against the wall, flush with the floor
–Re-cement the floor.
–As the cement starts to dry (but before it fully hardens) take out the wooden board.

There will be a channel or gap where the wooden board sat. The channel collects the groundwater, which then seeps down through the soil and gravel and into the perforated pipes. The water travels through the pipes to the sump pit, which should sit in the lowest corner of the basement.