sump pump inside 3" pipe?

Brock · March 2011

I have a 3" PVC pipe about 10 feet deep in our basement, basically a tiny sump pit. Our main drainage is gravity and drains about 1 foot below the basement slab, but we also have a sump pump in case that got backed up. What I am wondering in the spring when things start to thaw our basement always gets cold and when I go look at the gravity drain it is running pretty good, I would guess maybe a gallon or two a minute. So I was thinking of pumping out the deep 3" drain to keep the water from moving under the slab and cooling it down. I do have a regular pump and have pumped it out and it helps noticeable, but fills back up in a day or two.

So does anyone know of an automatic sump pump that would fit in a 3" pipe?

mike95490 · March 2011

Re: sump pump inside 3" pipe?

maybe a small bilge pump for a boat, 12VDC ? Some are cylindrical, and may fit, but you have to watch the amount of lift they can manage.
A gallon per min ? Thats a LOT of water. Sure it's not a well ?

icarus · March 2011

Re: sump pump inside 3" pipe?

Look at a "Rule" automatic bilge pump. Available in 12 vdc and 24 vdc configs with a couple of different sizes.

Tony

Ralph Day · March 2011

Re: sump pump inside 3" pipe?

Do you really think the basement gets cool from water movement or would it be because your heating less (woodstove perhaps) and the basement gets less warmth?

I too have a gravity drain. The floor has a big ''O'' loop into the sump pump pit. Water table rises in the spring or after a major rainfall and the floor drains dribble into the pit, the water drains away (the footing drains are tied to the output and drain to the ditch 400 feet away). I've never noticed the basement floor slab getting cooler when this happens. I suppose you could tell with an IR imaging/thermometer do-dad, but that's not in my tool kit.

I have a sump pump too, for insurance purposes, tested every once in a while. It was a major load before the gravity drain went in. The footing drains also dribbled into the pit and had to be pumped out. The pump would run for 30 minutes, then rest for 10, then run again...for days on end. Unless the power went out. The gravity drain was done before the off-grid adventure began.

Sorry I haven't got any input on pumps, not a boating guy, but I think you might be looking to find an electrical load where you don't need one or want one. My 2 cents.

ralph

Brock · March 2011

Re: sump pump inside 3" pipe?

Yes I have shot it with an IR thermometer and it drops noticeably in the areas not heated. The basement is a heated living space and it has radiant heat in the cement. In the fall and winter it runs about 4 hours a day, in spring as soon as the snow melts it runs about 10 hours a day and that matches when the water starts to run out the drain. And yes it is about a gallon a minute, more at certain times.

This spring I just shut off the radiant to avoid heating the water passing around and under the floor, but it is quite a bit cooler downstairs now. I do have 2 inches of xps under all the floor and around the footings, but again with water moving I don't think it matters.

I will look at the marine pumps, I hadn't thought of them.

Brock · March 2011

Re: sump pump inside 3" pipe?

I messed with it today. I ended up running 350 feet of garden hose out to the far end of our lot and started a siphon. It has dropped about 6 inches in 12 hours. I am guessing the far end is about 10 feet below the floor so it will likely slow down as the water level drops. At least this way I am using no power and I can see if I should mess with it for the future.

The more I think about it I should just redo the gravity drain further out, maybe get it three feet below the slab instead of a foot, then I should have less water against the floor.

Ralph Day · March 2011

Re: sump pump inside 3" pipe?

If you're going to re-do the gravity drain think about using 6inch big O pipe. I used 4 inch in the first incarnation, plus backfilled with the removed dirt...crushed the pipe and it didn't work properly.

When I had the excavator and hoe ram back (first time for the hoe ram) they made sure there was no humps in the pipe. Below and over top of the 6 inch big O there's 3/4 clear stone. The drain is very well protected from crushing, I couldn't even break down the pipe by jumping on it, it's quite a bit stronger than 4 inch pipe.

The cross section area of 6 inch is more than 2x the 4 inch (pie r squared area of circle) . This gives you more than twice the capacity to remove water. If your ditch is graded away properly with no humps in it then you should be ok. Only once in almost 10 years have I heard the sump pump come on. That got me down the stairs pronto! It was spring and raining heavily for a few days. I unplugged the pump and watched, but the water level didn't get to floor level. There's only about 1 foot drop from the bottom of the pit to the far end of the ditch bottom, you have a lot more. Maybe the drain got damaged during backfill (gravel over the pipe helps protect) or was affected by some humps on it's traverse (builders transit is a must).

Good luck

Ralph

Brock · March 2011

Re: sump pump inside 3" pipe?

Good stuff. I used dual 4 inch lines, but they only put crushed stone for about 1/2 way, not sure why, probably just ran out of stone? I think it is pitched fine. The one issue I had is they wouldn't and said they couldn't connect the drain tile to the gravity drain. So they literally lay right next to one another running the entire length of the lowest side of the house sitting in crushed stone.

I had almost the exact same experience in heavy rain with the sump pump kicking on and I shut it off and watched. It never came up any higher and eventually went back to "normal" a couple of days later. I must have had about 10 gallons a minute running out the end at that point.

One of my initial concerns was the water freezing where it comes out, basically making an ice dam, but it hasn't happened yet, the running water must be warm enough to get it away, it does make a nice flat ice spot just down from the drain.

BB. · March 2011

Re: sump pump inside 3" pipe?

In our area, we use Landscaping cloth to reduce dirt/clay inflow into the gravel... This is not to any known code--Just my seat of the pants recommendations:

Dig ~5-10 inch trench (with correct pitch)
lay down 3-6 foot wide ground cloth in trench (peg cloth to side of trench--I preferred the 6' wide cloth--much easier to control)
lay down some rock.
lay down pipe (I put holes up if you don't want to bring water from wet area to dry area; holes down if you simply want all water out of area).
lay down more rock (as much as you can afford--at least cover top of pipe if holes are up)
wrap landscape cloth closed
Back fill trench (pack dirt best you can to prevent sinks later in rain).

Note: Use two 45 degree elbows (with short PVC section) to make 90 degree turns. If you ever need to snake/water blast clean drain pipe, it is much easier to make the 2x 45 degree turns vs 1x 90 elbow.

For surface drains and down spout PVC connections--I did not use PVC cement--If I ever needed to "adjust" the surface connections, I don't have to cut and replace joints.

-Bill

westbranch · March 2011

Re: sump pump inside 3" pipe?

Coincidentally, yesterday I spoke with a foundation contractor about a basement we plan to build this summer.
He did a foundation job that ended up being similar to Brock's circumstance, where after landscaping the house was in a slight depression on sloped ground... drainage worked poorly...

basement flooded...
FWIW:
He gave me a tip about putting in a "T" in the 4"/6" drain pipe a short way from the foundation and to put in a "stand pipe" with a cap to allow for checking for blockage/flow at that point. And then to try to 'daylight the exhaust end for inspection and possible clean-out. The stand pipe could also be used for access to pump out the perimeter drain loop...

niel · March 2011

Re: sump pump inside 3" pipe?

mike90045 wrote: »

maybe a small bilge pump for a boat, 12VDC ? Some are cylindrical, and may fit, but you have to watch the amount of lift they can manage.
A gallon per min ? Thats a LOT of water. Sure it's not a well ?

i just had to add my 2 cents. i get flows that heavy here sometimes from an underground spring not more than a foot below my basement. i know it was not always this bad, but has gotten progressively heavier in its flows as time has progressed since my home was built a century ago. how do i know that? easy, it had a dirt basement floor. concrete was poured sometime later. there are also other signs of this becoming more problematic as time marched on, but believe me it need not be a well to pour heavy water flows.

sump pump inside 3" pipe?

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sump pump inside 3&quot; pipe?

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sump pump inside 3" pipe?