If you’ve ever wondered, "What is a sump pump?" then you’re lucky, because you probably don’t need one. But for the unlucky owners of wet basements, here’s the scoop: A sump pump sits in the basement, either beneath (in the case of a submersible pump) or above the floor. It pumps out water that collects in the sump basin, discharging it to the outdoors. Installing one can be messy, so first try to fix the water problem some other way. If you do need a sump pump, get one with an alarm to alert you when the water reaches a certain level. Another feature to look for is a battery backup, which allows the unit to function even during a power outage. Test your pump regularly and make sure the check valve is functioning, so water doesn’t flow back into the basement.
There are a few rules to keep in mind about sump pumps.
The first is that you’ll never have to buy one if you purchase a house that never floods. The second is that, if you do buy a house with a water problem, there may be several ways to correct it before resorting to a sump pump and pit. Third, if you must buy a sump pump, buy a very good one—in fact, it may make sense to buy two or three!
I’m lucky with basements. Having purchased five houses in my life, not one has been wet. Some dampness in summer, yes, but nothing a dehumidifier couldn’t handle.
When being shown a house by an agent, try to begin your tour in the basement. If there’s evidence of a significant water problem (such as an active sump pit and pump or high-water marks on the walls), walk away before you fall in love with the kitchen or master suite. A wet basement is going to cause all sorts of problems beyond water—rust, rot, mold, and unhealthy indoor air.
Related: 7 Ways to Avoid Basement Flooding
If you simply must buy the house or have already bought it, try to stop water from entering. I’ve known homeowners who put in a sump pump only to abandon its use after installing an outdoor curtain drain that diverts water to a pond.
Installing or repairing gutters so they don’t drain near your foundation can also make a big difference. And if a walkway, patio, or pool deck slopes toward your house instead of away from it, they are contributing hundreds of gallons of water to your problem.
There are services that can re-level slabs so they drain away from the house, and many types of patios can be removed and reinstalled with the proper slope without too much expense.
Buying a Sump Pump
If your water problem is serious (e.g., a high water table that gets higher when it rains), you will need a sump pump. Here are some quick tips on selecting the right sump pump to buy:
• Choose a submersible pump over a pedestal pump if your sump basin has the space. Submersible pumps allow the sump pit to be covered with a lid, reducing pump noise and stopping debris from falling into the pit. An airtight lid also helps keep moist air from being released into your home.
• Buy a pump with a cast iron core, not one made of plastic. Cast iron helps to dissipate heat to the surrounding water, lengthening the life of the pump.
• To minimize the chance of clogs, the pump should have a no-screen intake design coupled with an impellor that can handle solids up to ½-inch in diameter.
• The switch should be mechanical, not a pressure switch, and the float should be solid so it can’t become waterlogged, fail to switch off, and burn out the pump.
Secondary and Backup Sump Pumps
A secondary pump installed right next to the first is a good idea too, especially if your basement has been converted to living space or if you store valuables there. If your primary pump fails or is overwhelmed, the back-up pump automatically takes over.
For extra insurance, a battery backup pump can also be installed. When the power goes out, as it often does in a storm, the battery-powered pump can continue pumping for up to two days, depending upon the demand.
Combination packages with two or three pumps are available. A less costly option is to install a water alarm and to keep a spare pump on hand should the primary pump fail.