Installing a Basement Sump Pump

Having a properly installed and functioning sump pump is crucial for keeping water out of your basement. Flooding can cause extensive damage, so taking the time to correctly set up a sump pump system will save you headaches down the road. This guide will walk you through everything you need to know to successfully install a basement sump pump.

Choosing the Right Sump Pump

The first step is selecting the appropriate sump pump for your specific needs. Here are some key factors to consider:

Pump Capacity

Determine how much water you need to be able to pump out of your basement. This depends on the size of your basement, severity of storms in your area, and other sources of water like groundwater intrusion. A 1/3 horsepower pump can typically handle 200-300 gallons per hour. Go larger if you need more capacity.

Discharge Pipe Size

Match the outlet pipe size to the pump capacity. A 1-1/2″ pipe is sufficient for 1/3 HP pumps. Go with a larger diameter for heavier duty pumps.

Power Source

Sump pumps can be powered by electricity or battery. Electric ones need to be on a dedicated circuit. Battery backup pumps provide protection during power outages.

Materials

Cast iron and thermoplastic are common pump housing materials. Stainless steel shafts resist corrosion. Look for sturdy construction.

For moderate drainage needs, a 1/3 HP thermoplastic submersible sump pump with 8′ to 10′ lift should suffice. Upgrade to a larger pump if you anticipate high water volume.

Sump Pit Size and Location

The sump pit is the container that houses the sump pump. It should be:

At least 18″ to 24″ in diameter and 24″ deep. Bigger is better to contain more water.
Centrally located in the basement, distant from foundation walls.
In the lowest spot where water naturally accumulates.

Dig through any gravel or fill beneath the basement slab to create the pit. Use an 8″-10″ PVC pipe liner to prevent collapse.

Discharge Line Installation

The discharge line carries water away from the sump pit to the outdoors. Key guidelines:

Use 1-1/2″ PVC pipe or larger depending on pump.
Slope the pipe upward at least 1/4″ per foot as it runs to prevent backflow.
Include a backflow check valve near the pump to prevent reverse flow.
Secure sections with PVC cement and install unions for future maintenance.
Consider insulating the pipe if it passes through unheated spaces to prevent freezing.

Run the discharge line out through the rim joist to daylight, sloping it the entire way so water flows out via gravity.

Electrical Hookup

Hire an electrician to wire the pump:

Use a dedicated 15 amp circuit with 12 gauge wire.
Install a ground fault circuit interrupter (GFCI) breaker for safety.
Make sure interior outlets are connected to separate circuits.
Connect the pump cord to a receptacle near the sump pit.
Anchor the electrical cable to prevent cords from getting wet or damaged.

For backup pumps, install a battery inside a marine battery box with a trickle charger to maintain a full charge.

Check Valve Installation

Installing a check valve on the discharge line is CRITICAL:

Locate it within a foot or two of the pit on the vertical pipe.
Ensure arrow points UP towards the discharge endpoint.
Secure the check valve tightly with stainless steel clamps.
Support the check valve so there is no strain on the sump pump.

The check valve will prevent water in the line from flowing back into the sump pit when the pump shuts off.

Sump Pump Positioning

Proper placement of the sump pump protects its functioning:

Set the pump at the very bottom of the pit on a brick or block to prevent clogging intake.
Keep at least 1″ clearance from the bottom to allow room for sediment buildup.
Ensure float switch has free range of motion without obstruction.
Attach the pump discharge pipe firmly to the outlet fitting.

Setting the pump slightly elevated allows debris to settle below the pump intake, keeping it from getting blocked up.

Pit Liner and Cover

Adding a sump pit liner and cover provides major benefits:

Use a perforated plastic bucket or liner to prevent pit walls from collapsing.
Line the bottom with gravel to further improve drainage and prevent clogging.
Install a tight sealing cover to keep out debris and hazardous fumes.
Drill holes for inlet and outlet pipes – seal them with silicone.
Attach cover securely so it stays put under pressure.

The right liner and cover will keep your sump pit in good working order for the long run.

Power Backup Tips

Backup power options prevent flooding during outages:

A battery backup sump pump provides 8-12 hours of protection.
Install a marine battery deep cycle unit for maximum runtime.
Connect the battery to a trickle charger when main power is on.
Check the battery every 6 months and replace it every 2-3 years.
Alternatively, use a generator to run the primary electric pump.

Having redundancy via a backup sump pump or standby generator provides great peace of mind.

Testing and Maintenance

Performing periodic maintenance ensures your sump pump is ready when needed:

Test the pump regularly by filling the pit with a garden hose.
Every 2-3 months, remove debris from the pit and check for clogs.
Listen for pump noises indicating issues like wear or blockages.
Replace the check valve every 3 years to prevent backflow.
Consider installing an alarm to notify you of high water or pump failures.
Keep a spare pump and parts like check valves on hand for emergencies.

Proactive testing and maintenance helps avoid flooding disasters down the road.

Installing a Basement Sump Pump: Step-by-Step

Here is a recap of the key steps involved in properly installing a basement sump pump system:

Select a sump pump with adequate capacity for your needs. 1/3 HP is typical for most homes.
Dig a sump pit at least 18″-24” wide x 24” deep in the lowest spot where water collects.
Install a pit liner and gravel to prevent collapse and improve drainage.
Run discharge piping sloped at least 1/4” per foot to daylight using 1-1/2” PVC pipe.
Connect a check valve close to the sump pump outlet to prevent backflow.
Have a dedicated GFCI electrical circuit installed to power the pump.
Position pump at the bottom of the pit while allowing sediment clearance.
Attach discharge piping securely to the pump outlet fitting.
Install a sealed sump pit cover with drilled openings for pipes.
Test the system thoroughly and perform regular maintenance.

Following these key steps properly will result in an effective sump pump installation that keeps your basement dry for years to come.

Frequently Asked Questions About Installing Basement Sump Pumps

Many homeowners have additional questions when learning how to install a basement sump pump. Here are answers to some of the most common FAQs:

How much does it cost to install a sump pump?

A basic sump pump system with labor will cost $800-$1,500 on average. Complex installations with backup pumps or extensive excavation can cost $3,000-$5,000.

Where should the sump pump discharge to?

Ideally, run the discharge line to a hillside away from the home’s foundation. Other options are storm drains, dry wells, or a drainage ditch. Avoid sewer lines.

What size breaker and wire does a sump pump need?

A dedicated 15 amp GFCI circuit with 12 gauge wire is ideal. The wire size prevents voltage drops over long cable runs to the pit.

How often should a sump pump run?

A properly sized pump may run frequently in wet conditions, sometimes multiple times per hour. Running often to keep the pit empty is normal sump pump operation.

What kind of backup power options work for sump pumps?

Battery backup pumps, standby generators, and power supply backup sump pumps can all provide redundancy during outages.

How do I test a sump pump?

Fill the sump pit with water using a hose or bucket. Let the pump cycle on and off to verify proper operation. Testing monthly is recommended.

What causes a sump pump to stop working?

Common causes are clogged impellers, stuck or worn out floats, blown fuses, tripped breakers, discharge pipe blockages, or pump burnout after years of use.

How long should a sump pump last?

With proper maintenance, a quality cast iron or thermoplastic sump pump should last 5-10 years on average. Cheaper pumps may last only 1-3 years.

Can you install a sump pump yourself?

If you have basic DIY skills, you can install a sump pump yourself. Electrical work should be done by a licensed electrician for safety.

Conclusion

Installing a properly functioning sump pump system requires careful planning and execution. Sizing the pump, excavating a sump pit, routing the discharge line, wiring the electrical supply, and configuring the valves and accessories all need close attention to detail. While it can be a major undertaking, a professionally installed system will provide vital protection against basement flooding for years to come. Follow the guidelines provided above and work with qualified professionals as needed throughout the process to end up with a sump pump system that you can rely on.