Where to place second sump pit
#1
04-04-22, 01:49 PM
Where to place second sump pit
Recently we had some flooding in our basement after a big storm. The water came ini through our sump pit. I had a 1/2 hp pump running and added a 3/4hp submersible pump (with a garden hose output). Despite this the pit continued to flood and overflow onto the floor. Water did not enter the basement from any other area.
My current pit has 3 corrugated black pipes coming into it (I assume these are French drains). Whenever we have an average rainfall, I never see any drainage from these black pipes, the water always comes from the bottom of the pit. Looking into the pit there are cracks in the bottom of it.
I have asked two water proofing companies come out to provide recommendations.
The first recommended sealing the current pit (so no water could come in from the bottom) and then putting a second (also sealed) pit in the opposite corner of the house and tying in the French drains.
The second recommended keeping the old pit as is and putting a new sump pit (unsealed) a couple of feet from the old pit, while also typing in the French drain to the new pit.
In the first situation, I'm guessing, it would force water table to raise up and engage the French drains. In the second situation, we'd be focusing on controlling the rising water table. Which one is best?
Also, would the second recommendation be any better if the second pit was not right next to the first?
Any thoughts would be appreciated!
My current pit has 3 corrugated black pipes coming into it (I assume these are French drains). Whenever we have an average rainfall, I never see any drainage from these black pipes, the water always comes from the bottom of the pit. Looking into the pit there are cracks in the bottom of it.
I have asked two water proofing companies come out to provide recommendations.
The first recommended sealing the current pit (so no water could come in from the bottom) and then putting a second (also sealed) pit in the opposite corner of the house and tying in the French drains.
The second recommended keeping the old pit as is and putting a new sump pit (unsealed) a couple of feet from the old pit, while also typing in the French drain to the new pit.
In the first situation, I'm guessing, it would force water table to raise up and engage the French drains. In the second situation, we'd be focusing on controlling the rising water table. Which one is best?
Also, would the second recommendation be any better if the second pit was not right next to the first?
Any thoughts would be appreciated!
#2
04-04-22, 02:36 PM
Member
So to be clear, you had (2) sump pumps running and they could not manage the inflow of water?
An average sump pump can move at least 2500 gallons per hour. Something just doesn't seem right with your current setup, are you positive it's working correctly?
An average sump pump can move at least 2500 gallons per hour. Something just doesn't seem right with your current setup, are you positive it's working correctly?
#3
04-04-22, 04:23 PM
Originally Posted by sumppit
I had a 1/2 hp pump running and added a 3/4hp submersible pump (with a garden hose output).
I've got an old farmhouse built over a spring, so it often has water, the basement was literally poured with channels along the walls to go to the sump.
Hurricane Ida was the first time in, eh, 45 years, that I'd seen our sump pump unable to keep up with the water level- however, ALSO saw standing water in places I've NEVER seen in almost 50 years living here.
If you've got a problem, first suggestion is to check gutters, downspouts and drains- ALSO check low-spots and shrubs for groundhog holes, or mole/vole tunnels that might direct water right back into the subsoil under the basement.
Next, I'd check the pumps themselves - a continuously running pump motor will heat up quickly, and hotter means less efficient and uses more power, which makes it even less efficient. During Hurricane Ida, I actually ended up suspending a 6" fan above the pump to cool it down (fan cord clove-hitched around a sewer pipe so it could NOT fall in and short out). Having a fan to cool the sump pump motor made a BIG difference in temperature and performance, and likely saved my furnace and hot water heater from getting swamped.
Followup question - had any trees removed say, 2-3-4 years ago? In many cases tree roots will be drawn to sumps, when the trees are cut down, the roots rot away leaving a "pipeline" from the yard directly back to the sump. Willows are notorious for this.
#4
04-04-22, 04:33 PM
I actually had 4 pumps
1) I have a 1/2 hp Zoeller pump in the bottom of the pit which is hooked to a 2" discharged pipe.
2) I have a water driven backup pump
When I saw the water level rising in the pit, 3) I dropped in a 3/4hp submersible pump which discharges to garden hose and, 4) I wedged in a pool cover pump which also discharges to a garden hose
1) I have a 1/2 hp Zoeller pump in the bottom of the pit which is hooked to a 2" discharged pipe.
2) I have a water driven backup pump
When I saw the water level rising in the pit, 3) I dropped in a 3/4hp submersible pump which discharges to garden hose and, 4) I wedged in a pool cover pump which also discharges to a garden hose
#5
04-05-22, 09:16 AM
Go out during a heavy rain and check for water puddling up against the foundation. That will have to be fixed so gutter and downspout water runs away from the house.Also eliminate any depressions along the foundation filled with gravel or mulch and repack with hard dirt similar to the rest of the lawn.
The sump pit liner, if any, should have holes in or near the bottom, but not be filled with rocks. You will have to figure out something to keep dirt from coming up through the holes, exactly how may vary from one house to the next.
For more than one sump pump, each should have its own outlet pipe. A garden hose is not fat enough to properly carry the volume of water from the pump.
Normally a second pit is not needed unless you can't fit a needed second sump pump and floats in the single existing pit.
If you do have a second sump pump near the first, they should be interconnected with a 4 inch pipe straight across and entering at the bottom of each pit.
The sump pit liner, if any, should have holes in or near the bottom, but not be filled with rocks. You will have to figure out something to keep dirt from coming up through the holes, exactly how may vary from one house to the next.
For more than one sump pump, each should have its own outlet pipe. A garden hose is not fat enough to properly carry the volume of water from the pump.
Normally a second pit is not needed unless you can't fit a needed second sump pump and floats in the single existing pit.
If you do have a second sump pump near the first, they should be interconnected with a 4 inch pipe straight across and entering at the bottom of each pit.
Last edited by AllanJ; 04-05-22 at 09:34 AM.
#6
04-06-22, 05:59 AM
The purpose of the sump pump and perimeter drain pipe system is to artificially lower the water table under the house. You do not want to raise the water table to "engage the French drains" or to "activate the sump pump better."
In proper operation the French drains (perimeter drain pipes) should contain mostly air through their full lengths, that is, not full of water.
The purpose of a French drain is to carry water from its vicinity to someplace else. Although some water will stay behind and soak down below, this is not an intended result.
In proper operation the French drains (perimeter drain pipes) should contain mostly air through their full lengths, that is, not full of water.
The purpose of a French drain is to carry water from its vicinity to someplace else. Although some water will stay behind and soak down below, this is not an intended result.
#7
04-06-22, 10:10 AM
From what it sounds like, the french drains and the sump pit all worked exactly the way they are supposed to. The problem was the pump(s) couldn't discharge the incoming water fast enough.
Do you know where the main pump discharges to? Could that line be clogged or maybe broken, effectively pumping the water right back into the french drains? (It happens more often than you'd think that someone has the bright idea to pump the water 3' from the foundation...)
If this is new issue, maybe the pump is failing. Poor seals or something that is causing it to pump much less than expected.
I wouldn't put too much value into the temporary pumps you used. Garden hoses aren't great for moving large quantities of water.
I wouldn't immediately start adding new sump pits until you determine it will actually help.
Do you know where the main pump discharges to? Could that line be clogged or maybe broken, effectively pumping the water right back into the french drains? (It happens more often than you'd think that someone has the bright idea to pump the water 3' from the foundation...)
If this is new issue, maybe the pump is failing. Poor seals or something that is causing it to pump much less than expected.
I wouldn't put too much value into the temporary pumps you used. Garden hoses aren't great for moving large quantities of water.
I wouldn't immediately start adding new sump pits until you determine it will actually help.
