The backup stack
Pump, battery and valve: three jobs, three devices
A basement is dry when each way water arrives has a device waiting for it. This page says what each one does, what it can't do and what we check on it every year.
We install all three and sell none of them as a package. The walk-through decides which your house needs. A house on high ground with a sewer that has never backed up may need only a pump and a battery. A house on a low block with a combined sewer needs the valve first.
One at a time
What each device stops
Sump pump
Sits in the pit at the low point of the floor and pushes groundwater out through the discharge line when a float rises.
Stops: water rising through the slab or the footing drain
Doesn't stop: a sewer backup, a power cut
Yearly: lift the float, run the pump, clear the outlet
Battery backup
A second pump with its own float and a sealed battery. It takes over when the main pump or the power fails.
Stops: a power cut or a dead main pump, for as long as the battery lasts
Doesn't stop: a sewer backup
Yearly: load-test the battery, replace it on its schedule
Backwater valve
A flap in the main drain line that closes when sewage flows backward toward the house.
Stops: a sewer surcharge up the floor drain, the tub or the toilet
Doesn't stop: groundwater or a power cut
Yearly: open the lid, clear the flap, check that it swings
Before we cut the slab
Four things we settle first
Where the water goes
A discharge line has to end outside, away from the foundation. We walk the route, and check your town's rule on sump water and the sanitary sewer.
Where the valve goes
On an accessible stretch of the main drain line, ahead of every fixture it protects. Fixtures above the valve keep draining to the sewer; fixtures below it will need to be closed in a storm.
What the pit holds
A pit sized to the pump, with a sealed lid and a clean bottom. A pit that is too small makes the pump cycle on and off.
What the battery runs
Which outlet, on which circuit, and how long the battery lasts at the inflow we measured. We write the run time on the quote, and the panel work, if there is any, goes to an electrician.
Questions about the three
Is a battery backup the same as a generator?
No. A battery backup runs one pump. A generator runs the house, and still needs a pump to move the water.
Can one pump do the work of a battery backup?
A bigger pump moves water faster but still stops when the power does. The battery is a second pump on its own supply.
What happens to the toilet when the valve closes?
While the flap is closed, a fixture below the valve can't drain. We tell you which ones those are, and what to do in a storm.
How long does an install take?
A pump replacement is usually one visit. A valve means opening the slab and takes longer; we say how long on the quote.
Which of the three does your house lack?
We walk the basement, photograph the pit and the drain line, and send you the findings.