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How Sump Pumps Work

Sump Pump Installation

You can have a professional install a sump pump in your home, but if you're a reasonably handy person, it may be a job you can take on yourself. Here's an overview of how to install a sump pit and pump in your basement.

  1. Determine where water, sewer and utility lines enter your home. You want to put your sump pit away from this ­  existing infrastructure at the lowest point of your basement (you can use a laser level to determine this point). The pump should be at least 8 inches (20 centimeters) away from an outside wall and close to a ground fault circuit interrupter (GFCI) outlet.
  2. Figure out how you are going to route the outlet pipe -- usually 1 1/2 inch to 2 inch (3.8 to 5 centimeter) PVC. Running it up through a rim joist is usually the easiest way to get the pipe to the outside.
  3. Purchase your sump pump and liner together. The liner, essentially a heavy plastic tub with slits to allow water to enter, will determine the size of the hole you dig. You want to dig the hole at least 3 inches (7.6 centimeters) wider than the liner and about 6 inches (15.2 centimeters) deeper. You can use the liner as a starting template and enlarge your outline by 3 inches (7.6 centimeters).
  4. Dig the hole to the depth recommended by the sump pump manufacturer, then level the bottom. The easiest way to cut through the concrete is to use a jackhammer.
  5. Put the liner into the hole and fill around the outside with coarse gravel. Also put about 6 inches (15 centimeters) of gravel in the bottom of the pit. Tamp it down firmly to ensure the bottom stays level.
  6. Attach the discharge pipe to the pump, and place the pump into the pit, making sure it stands upright and level.
  7. Cut a piece of PVC drain pipe 1 foot (30.5 centimeters) long. Drill a hole in the rim joist to accommodate the discharge pipe and install it in the hole.
  8. Measure and cut pieces of PVC pipe to run from the pump to the inside of the pipe through the rim header. Dry fit all the pieces, and when you're sure they are right, cement them together.
  9. On the outside, fit a piece of discharge pipe onto the pipe protruding through the rim header. Run it to the discharge area, then cement the pipe in place. The discharge pipe shoul­d have a small vent hole that's out of the water but drains into the pit. This vent hole is designed to prevent an air lock from forming in the lower part of the pump.
  10. Finish up by caulking around the hole in the rim header both inside and outside and supporting the discharge pipe inside the house by attaching it to walls or joists.
  11. Finally, adjust the float valve on the pump following the manufacturer's directions. Check the operation by pouring in two or three buckets of water, then plug in the pump.


Once you've installed the pump, a little routine maintenance will help keep running smoothly. So how often should you head to the basement with a bucket of water?