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What Size Basement Pump Do I Need for My Home?

What Size Basement Pump Do I Need for My Home?

Heavy rain and flooding can cause significant damage to a home if the proper precautions aren't taken. A sump pump is the saving grace for houses located in areas with basements that receive a lot of rain or are in a floodplain. The sump pump, sometimes called a basement pump, is a plumbing appliance that ensures water is contained then piped away from your home’s foundation, keeping your basement and the rest of your home dry and free of water intrusion and water damage. However, it's important to understand which size sump pump works best for your particular home. Let's take a look at how to determine how big your basement pump should be:

Estimate the capacity

During a rainy day, run your sump pump until the water recedes to the shutoff level. Turn the pump off for one minute by unplugging it (DO NOT LEAVE IT UNPLUGGED), then measure how far the water rises inside the sump pit within that time. On a rainy day, a typical basement sump pit will receive 20 gallons of water, or 20 inches, in one minute. Multiply the number of inches the water rose to by 60. This will allow you to estimate the volume of water received in an hour. Then multiply that figure by 1.5 to build in a safety factor for your pumping capacity.

Your equation should look like this: inches water rose x 60 minutes x 1.5 = gallons per hour capacity required.

Motor power

The strength of the sump pump's motor will determine how powerful it is. Homeowners can choose between the .33-horsepower, which is standard, the .25-hp (¼ hp), the .05 hp (½ hp)-hp or even a ¾ hp. If you live in an area that floods a lot, the .5-hp or ¾ hp pump might be the best option, as it can remove 3,000 gallons of water or more per hour. For those who don't need a large sump pump, the .25-hp motor is a good pick. Please note that many manufacturers are now listing pumping capacity right on the package so be sure to look for that information before purchasing a sump pump.

Other considerations

While the estimation equation and motor power are certainly great indicators for what size basement pump you'll need, there are a few other factors to consider. If you have a wider sump pit, it will be able to hold more water and could throw off the equation. Homeowners also have to watch the height that water has to travel as it moves through the discharge pipe, known as the vertical lift or static head. The pump will have to work harder to push water higher and out as the distance increases.

If you need help determining what size sump pump will be best for your basement or installing one, call a Roto-Rooter plumber today. These experts have the tools and expertise necessary to prescribe the best solution for your home.


Sump Pumps