Sump pit idea?

[IndyGunworks]

I have a thought I would like to run by the expertise on ingo. Its probably not been done before and there is probably a reason for it that I am just not seeing. Of all the basements I have seen flood its been because of a failed sump pump. either it cant keep up, or the power goes out and there isn't proper battery back up.

with that in mind I started wondering why you couldn't have a 5 foot by 5 foot "room" poured off to the side of the basement. you could have a ladder for access and put an insulated cover on top of it to prevent freezing.

Currently all the basement plans I have been seeing have an inside perimeter drain and an outside drain that both connect to a sump pit INSIDE of the enclosed basement.

I would think that instead of running the outside drain to the inside, it would be just as easy to run the inside drain to the outside "pump room"

With this setup the ground should keep anything from freezing, and should a pump fail the water overflow would be contained to the pump area.

What am I missing here?

 

[hornadylnl]

Water seeks it's own level. If the pit fills high enough to reach the level of your floor, it's still going into your basement. I've the traditional setup you describe but my outer perimeter drain has a tile that goes out and eventually dumps in a creek a half mile away. Do you have a ravine or creek lower than your basement floor grade? If so, tile to it.

 

[IndyGunworks]

I do not have anything lower... I will be reliant on a pump.

If water is high enough to be flowing OVER the external pit, then the whole area around the basement is flooded anyways. Where I would be putting this basement I am not concerned with surface water whatsoever, but ground water is a real concern. It seems to me if this pit were external and a pump were to fail, the water level in the external pit would eventually equalize w/ the current water table until I could get the sump running again. either way I feel like it would prevent a lot of flooding in the basement.

 

[88GT]

What am I missing here?

Cost? What you describe seems to be very cost ineffective. Even accounting for the possible cost of repairing/replacing items due to a flooded basement.

But what you describe also sounds like a dry well of sorts.

 

[hornadylnl]

When my sump pit is filling quickly, I can unplug my pump and the level stays about 6" from the top. I put in 1000' of tile in to tie into an old field tile. It ties into a low spot with a drain. I was told that low spot would have to reach 4' before getting to my floor level. I've seen that low spot get so high that it overflows into the field around it and my sump pit still doesn't go any higher. I also have a check valve in the tile just off the basement. Cost about $10k or so bu haven't had any water in the basement in 3 years. Knock on wood.

 

[IndyGunworks]

Cost? What you describe seems to be very cost ineffective. Even accounting for the possible cost of repairing/replacing items due to a flooded basement.

But what you describe also sounds like a dry well of sorts.

Probably less than 1k dollars added to the cost of the basement. Seems pretty cheap when compared to how much it would suck just to replace flooring and drywall in a finished basement.

 

[fastwally]

Do you have natural gas? If you do, use the 1k towards a generator big enough to run your essentials. Doesn't have to run the whole house. That's what I did 15 years ago and have never had a problem. You know there is always the chance your pump could take a crap.

 

[IndyGunworks]

I realize that chance, which is why I am planning on TWO pumps. I wont have natural gas, but I will have a 1k gallon propane tank that will only be used for supplemental heat when the heat pump cant keep up, and cooking. I have thought long and hard about a propane generator hooked into the tank wired to kick on automatically if the power fails.

 

[Cameramonkey]

There are already cheaper existing methods. 12v backup pumps powered by deep cycle marine batteries (with alarms to let you know when the battery is kaput) as well as one unique system I saw that is powered by a garden hose. (flowing water drives a pump which draws the waste water PLUS the sump water out)

I'll give you an E for effort though. Sounds like a good theory at first, and in fact, one that is currently being dug as we speak (but a wee bit larger scale):

Indianapolis Storage Tunnel System | Citizens Energy Group

 

[hoosierdoc]

We have the water backup. Pumps one in and two out theoretically. Makes me nervous though.

 

[IndyGunworks]

link to the water backup?

 

[SmileDocHill]

It is my understanding that the entire point of having a hole in your basement floor for the pump is to prevent buoyant pressure from lifting your basement and causing structural fractures in your foundation or house. Picture your basement walls and floor as a boat and the ground water as, well, water. To prevent the basement from lifting up and causing damage you need to keep a hole in the bottom of that boat. To keep the boat from filling full of water you have to keep the water level low or pump it out. In your fix you've plugged the hole and allowed the water level to increase in height around the basement. The reality is that your example would only allow the water level to increase in that manner for a short time period when something fails. How much time is needed to get the basement to float and start breaking things? That is the unknown your gamble would hinge on.

 

[SmileDocHill]

I installed the water backup in my previous home. I timed and measured how much water flowed into our sump pit when it was really raining. I would have had a good MAYBE hours worth of pumping from a battery backup AT BEST. I had the full amount allowed of municipal water pressure to work with. It takes higher pressure low volumetric flow water and trades uses that pressure to pickup more water. Discharge is more volume but less pressure.

Downside risk...the system works on mechanical valves and floats only. If for some reason your sump fails or a seal fails and it is being used for a decent amount of time rather than just during an outage you are looking at an eye opening water bill! I have a previous neighbor that made this mistake.

 

[Cameramonkey]

We have the water backup. Pumps one in and two out theoretically. Makes me nervous though.

Give it a test! fill the tub then put something like this in the tub attached to your garden hose and pipe it directly into your sump well. disable your main pump and activate the water pump. See how well it keeps up.
Amazon.com: Attwood WaterBuster Portable Pump: Sports & Outdoors

If it cant, you can always turn off the tub pump and work toward Plan B. (traditional battery powered backup sump)

link to the water backup?

neat idea, but bear in mind this wont work if you have well service. (power out=no well pump=no worky!)

Zoeller 503-0005 Homeguard Max Water Powered Emergency Backup Pump System - Amazon.com

 

[jamin]

I understand what you are looking to do, but I think you are over engineering it. What I have seen done and what I will do when I build is install an outdoor sump pit. Basically it's a 16-18" culvert with a cap on the bottom stood vertically near the house. Instead of bringing the outside perimeter drain into the basement pit tie them into the outdoor pit and throw a pump in it.

I have never understood the point of intentionally bringing water into the house then turn around and pump it away, if it's outside already keep it there. I would then install the inside perimeter drain to the inside sump pit.

 

[IndyGunworks]

that's not a bad idea.... wouldn't be too hard to keep it from freezing either..... still have the inside drain for the water that's already on the inside perimeter drain, which shouldn't be much if the outside drain is doing what its supposed to be doing, and no way for copious amounts of outside water to easily penetrate the inside. I think I will ask the basement contractor about this idea.

 

[CathyInBlue]

It is my understanding that the entire point of having a hole in your basement floor for the pump is to prevent buoyant pressure from lifting your basement and causing structural fractures in your foundation or house. Picture your basement walls and floor as a boat and the ground water as, well, water. To prevent the basement from lifting up and causing damage you need to keep a hole in the bottom of that boat. To keep the boat from filling full of water you have to keep the water level low or pump it out. In your fix you've plugged the hole and allowed the water level to increase in height around the basement. The reality is that your example would only allow the water level to increase in that manner for a short time period when something fails. How much time is needed to get the basement to float and start breaking things? That is the unknown your gamble would hinge on.

Not entirely accurate.

The purpose of drain tile and dimple membrane is to give the water that reaches the outside surface of your basement an avenue to drain away by gravity. That alone is sufficient to prevent the basement as a boat phenomenon. No real need for a sump pit. The thing the sump pit gives is collection volume. The thing the collection volume gives is the ability to trade off duty cycle on your sump pump for power/rate of flow on same. You could just as easily affix a small sump pump to the output of your weeping tile and have it running nearly continuously. Problem is, it's not raining continuously. It rains in bursts. Bursts would could easily overwhelm a low-flow sump pump.

You let the sump pit fill up and then run a high-flow sump pump to drain it all the way down, then you can turn the pump off and let it rest/cool/just not run up your power bill. This allows your sump pump to not run at all the vast majority of the time, but when it does need to run, it has the capacity to not just keep up with the inflow of water, but to easily outstrip the inflow of water, insuring against flooded basements.

Now, as to the OP's idea, all you really need is volume, whether deep or wide, doesn't really matter, but I'd prefer deep, and a powerful sump pump. The pit, in order to readily accept feeds from all sides of the basement, should be as centrally located as possible. If it's on one side of the house, the weeping tile from the opposite side might have a harder time draining.

I have never understood the point of intentionally bringing water into the house then turn around and pump it away, if it's outside already keep it there. I would then install the inside perimeter drain to the inside sump pit.

There is wisdom in your lament, but consider this, with an external sump pit, are you then guaranteed against ever flooding your basement? Will your basement washing machine never overflow? Will your basement water heater never leak? Will your first floor plumbing run through the floor (basement ceiling) never rupture? Of course it can. And when it does, where will all that flood water go? How will you get rid of it? Just wait for it to drain into the interior weeping tile and from there to the exterior weeping tile and from there to the exterior sump pit? Or, with an interior sump pit, just squeagie it straight into the interior sump pit and be done with it?

The only external sump solution is for a house on a serious grade, where the weeping tile can be laid downhill a fair distance away before discharging.

 

[jamin]

I'm saying have both, an outside pit and then another pit inside. Let the outside pit handle water outside and the inside handle water inside. If the outside pump fails, then the inside pump can take care of the water via the interior perimeter tile. Now if you loose power and have no generator then nothing is gonna work.

 

[CountryBoy19]

I understand what you are looking to do, but I think you are over engineering it. What I have seen done and what I will do when I build is install an outdoor sump pit. Basically it's a 16-18" culvert with a cap on the bottom stood vertically near the house. Instead of bringing the outside perimeter drain into the basement pit tie them into the outdoor pit and throw a pump in it.

I have never understood the point of intentionally bringing water into the house then turn around and pump it away, if it's outside already keep it there. I would then install the inside perimeter drain to the inside sump pit.

Ding, Ding, Ding... WINNER!!!!

My dad has been in the drainage business for 2 decades now. We constantly had trouble with our basement walls "seeping" and "leaking" during rains and the indoor pit couldn't keep up during really heavy rains. After the 2nd time our basement flooded he had enough. He isolated the outside perimeter drain from the inside sump pump and dug and outside sump pit. Connected the outside perimeter drain to the outside pit and left the inside drains on the inside pit. He hasn't had a problem yet. As a matter of fact, the inside sump pump rarely even runs now.

It is my opinion that this is the best way to do it. Keep as much water as possible outside of the basement to start with.

The outside sump pit is SUPER CHEAP to do. Go get yourself the appropriate length of "dual wall, corrugated pipe" of the appropriate diameter. "Dual wall, corrugated pipe" is the pipe that looks like corrugated field tile on the outside but also has a second smooth wall inside; that is likely going to be your cheapest option. Now, dig the pit at the same time your foundation/basement walls/perimeter drain is being dug. Then, when they come pour your basement walls have them pour a little concrete in the bottom of that pit then stick the pipe down into the concrete to "set it in place".

There is wisdom in your lament, but consider this, with an external sump pit, are you then guaranteed against ever flooding your basement? Will your basement washing machine never overflow? Will your basement water heater never leak? Will your first floor plumbing run through the floor (basement ceiling) never rupture? Of course it can. And when it does, where will all that flood water go? How will you get rid of it? Just wait for it to drain into the interior weeping tile and from there to the exterior weeping tile and from there to the exterior sump pit? Or, with an interior sump pit, just squeagie it straight into the interior sump pit and be done with it?

The only external sump solution is for a house on a serious grade, where the weeping tile can be laid downhill a fair distance away before discharging.

Not entirely true. There are 2 ways to have an outside sump pit and take care of all of the problems you just described.

A) If you don't mind redundancy for added peace of mind you can have your traditional indoor pit AND an outdoor pit that are 100% isolated from each other. That way the only water the indoor pit has to deal with is the water you put in the basement (burst pipe, overflowing washing machine etc) and the water that sneaks past the exterior perimeter drain.
B) If you don't do an indoor pit you would do floor-drains that lead to the exterior pit with a back-flow prevention device. Obviously to work properly an outdoor pit has to be just as deep as an indoor pit would be (a few feet below your basement floor level) so that isn't a problem.

 

[IndyGunworks]

I am thinking this outdoor pit is what I want to do. I am still trying to debate the merits of leaving the interior drains go to an inside sump pit. I am thinking about hooking both intereior and exterior drains to the external sump pit completely isolating ground water from the inside of the basement.

I will still install a pit on the inside for water that originates inside, but it will not be connected to any of the drains. I think I will put that on a manual switch as well as a float. I will probably just pump that water into the exterior sump pit anyways.

I am going to have to find a sump tile large enough to accept two pumps as I want redundant systems.