An idea for a back up to a sump well.
#1
12-03-14, 03:11 PM
An idea for a back up to a sump well.
Hello All,
We live in a 100 yr old farm house. I have one sump well in the main part of the house, and another in an addition, where the floor is about 4 inches lower than the main house.
I know the water table is just below the concrete floor, I've had to smash out a section and pour new concrete. I've had battery backups, and they've all failed over time. We just had a prolonged power outage, and the lower section of the basement flooded. About 2 inches.
My solution is to build a concrete barrier about 16 inches high around the sump wells. The reasoning is that the water table will not rise much above the opening, given the fact the water table normally sits under the floor, and there won't be any water in the ground pushing down on the water table, and therefore pushing the water up through the sump well any higher than the water table level. Maybe a couple of inches.
Any thoughts? The wife wants to verify my mad plans before going ahead
We live in a 100 yr old farm house. I have one sump well in the main part of the house, and another in an addition, where the floor is about 4 inches lower than the main house.
I know the water table is just below the concrete floor, I've had to smash out a section and pour new concrete. I've had battery backups, and they've all failed over time. We just had a prolonged power outage, and the lower section of the basement flooded. About 2 inches.
My solution is to build a concrete barrier about 16 inches high around the sump wells. The reasoning is that the water table will not rise much above the opening, given the fact the water table normally sits under the floor, and there won't be any water in the ground pushing down on the water table, and therefore pushing the water up through the sump well any higher than the water table level. Maybe a couple of inches.
Any thoughts? The wife wants to verify my mad plans before going ahead
#2
12-03-14, 03:50 PM
Probably not going to work. Once the water table rises above the floor level it will start to seep in through R the floor, around the perimeter, cracks, etc. You need to keep the water table lower then your floor level in order to keep your basement dry.
We lose power frequently and I'd never rely on a battery to keep my basement dry during a storm and power outage. Several gallons of gas and a generator keeps the pump running for hours on end. Also keeps my lights on and the heat running!
We lose power frequently and I'd never rely on a battery to keep my basement dry during a storm and power outage. Several gallons of gas and a generator keeps the pump running for hours on end. Also keeps my lights on and the heat running!
#3
12-03-14, 07:20 PM
We never had the water table rise high enough to start seeping in through the base of the basement walls. The problem is in the half of the basement that is sitting at the water table. That is, just underneath the concrete floor. The last power outage was about 24 hours, and it came up through the well, and covered the floor in about 2 inches of water. I had the generator going well into the night, then I shut it off thinking I'd fire it up in the morning. By that time it was too late.
My thought is to have the concrete wall around the well to contain it for the short term.
My thought is to have the concrete wall around the well to contain it for the short term.
#4
12-03-14, 10:50 PM
Every home is different. If you are indeed dealing with a few inches of rise from below then the coffer dam approach may help from one perspective. However, it would hinder a water intrusion from other sources, like a broken water line.
You said you had the generator running for hours, I assume the sump pump was cycling and not running continuously?
Two sump pits are good and even though they are at different levels on the inside they may be similar below the floors. If you took the higher level pit down an extra 4" it might be pumping water out at the same level as the lower pit, one form of back-up. If the lower pump fails, the upper pump controls the water level.
As for keeping them powered, an automated generator back-up is probably the overall best solution. They ain't cheap, but they solve the problem, add value, and last for many years.
If it is "time" you are hoping to buy, like longer intervals between pump cycles, then a larger pit is needed. 2 inches of water over 400 sq ft is about 60 gallons. I'd need to know more about your landscaping and that water table before making any suggestions though. But a larger pit will slow the cycle rate if nothing else.
Last, is there any place on your property that is below the bottom of that lower floor, a gravity drain option? Or even a large dry well if that area has a lower water table.
Bud
You said you had the generator running for hours, I assume the sump pump was cycling and not running continuously?
Two sump pits are good and even though they are at different levels on the inside they may be similar below the floors. If you took the higher level pit down an extra 4" it might be pumping water out at the same level as the lower pit, one form of back-up. If the lower pump fails, the upper pump controls the water level.
As for keeping them powered, an automated generator back-up is probably the overall best solution. They ain't cheap, but they solve the problem, add value, and last for many years.
If it is "time" you are hoping to buy, like longer intervals between pump cycles, then a larger pit is needed. 2 inches of water over 400 sq ft is about 60 gallons. I'd need to know more about your landscaping and that water table before making any suggestions though. But a larger pit will slow the cycle rate if nothing else.
Last, is there any place on your property that is below the bottom of that lower floor, a gravity drain option? Or even a large dry well if that area has a lower water table.
Bud
#5
12-04-14, 07:36 AM
Were on 5 acres, and it's all flat. The other thing we did was dig a pond about 200 feet from the house. The sumps used to shut off in the winter, but now they seem to cycle year round. The pond level is real high right now, and I thought of draining it to below the water table. Not sure if that would help, and she's frozen over now. I'd say they cycle once per half an hour. When the generator was hooked up, they were cycling the same, but I had to shut it down and get some sleep. When I woke up, the lower part flooded with 2 inches. It only took 7 hours, so that's why I'm thinking about building the dam around the sump well. Agreed, an auto generator is the way to go.
As far as the "higher" sump, whoever built it did a good job. It's a formed concrete ring, and it's deeper than the "lower" sump well, which is a plastic type, and smaller and not as deep. I would say they are about at the same level in the ground. When I woke up the morning of the flood, the higher sump well was still about an inch or two down, so it seemed to be settled at that level.
As far as the "higher" sump, whoever built it did a good job. It's a formed concrete ring, and it's deeper than the "lower" sump well, which is a plastic type, and smaller and not as deep. I would say they are about at the same level in the ground. When I woke up the morning of the flood, the higher sump well was still about an inch or two down, so it seemed to be settled at that level.
#6
12-04-14, 09:56 AM
One house I worked on, a single mom and friend, was having flooding problems. Seems the previous owner had installed two concrete cylinders on top of a spring right next to the house and added a pump for water. By damming up that spring, the water inside the cylinders (4' diameter and about 6' tall) filled to 3' above the basement floor. Then the trench they dug to get the water line from the cylinders to the house provided a perfect path for this spring to try and fill the basement. As it turned out, the water from the spring was contaminated with road salt so a new well was drilled but the cylinders were left in place. I busted a hole in the side at the bottom to relieve the pressure and allow the spring to run as it had before and the basement flood was gone.
Just wondering if your pond is contributing to your water table.
In any case, 5 acres is plenty of land so you may have the option to install a dry well some distance from the house. You will probably have to dig some test holes to identify the best location, but there is probably a low spot somewhere underground. Are you on a well or city water. If a well, talk to the well contractor as they usually are very familiar with what is under the surface.
Bud
Just wondering if your pond is contributing to your water table.
In any case, 5 acres is plenty of land so you may have the option to install a dry well some distance from the house. You will probably have to dig some test holes to identify the best location, but there is probably a low spot somewhere underground. Are you on a well or city water. If a well, talk to the well contractor as they usually are very familiar with what is under the surface.
Bud
#7
12-10-14, 02:56 AM
battery backup pumps aren't all we hope they'd be 
next time don't shut off the generator - most will run @ least 6hrs & that's enough sleep if you're having a house emergency,,, i don't think there's much you can do other than that,,, you might test the pond to see if its leaking - if so, you might be able to seal the leak(s) w/bentonite,,, anytime 1 builds below the wtr tablel, expect trouble
IF you're on city wtr, consider zoeller wtr-power'd backup pump(s)
next time don't shut off the generator - most will run @ least 6hrs & that's enough sleep if you're having a house emergency,,, i don't think there's much you can do other than that,,, you might test the pond to see if its leaking - if so, you might be able to seal the leak(s) w/bentonite,,, anytime 1 builds below the wtr tablel, expect troubleIF you're on city wtr, consider zoeller wtr-power'd backup pump(s)
