Sump pump info bleg

I have a problem over at Ian’s place. Regular readers might recall that last year’s Monsoon caused all sorts of problems there. Basically, there were water incursions where no water was supposed to have been able to incur, and I spent a good part of that summer fixing things that weren’t supposed to break.

Now this year, I have a problem with water percolating up through the concrete floor. At first I thought it was caused by something I had done. But that issue was corrected a month ago and my wet problem is only getting worse. Meanwhile Monsoon goes on and on. I’m finally driven to the conclusion that – deep breath – I’m not at fault. Ma Nature is.

If I’m right, I’ll know when the problem starts to go away as soon as it stops raining every frickin’ day. And that will mean that there’s an obvious fix: I need to install a sump pump. Because if the problem stops when Monsoon does, that means water has found a way under the slab and it’ll just happen again the next time we have a wet Monsoon.

Now: I can borrow a perfectly serviceable jackhammer, so retrofitting the floor with a sump isn’t a daunting prospect. But I’ve never done it before and I’m unfamiliar with sump pump hardware built in this century. I saw them a lot in my youth, in Michigan, but both those things are far in my past.

So I’m reaching out to the TUAK commentariat. Anybody have experience with modern sump pump hardware? I have to make recommendations to Ian, who I’ll have to convince to pay for the hardware.

About Joel

You shouldn't ask these questions of a paranoid recluse, you know.
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17 Responses to Sump pump info bleg

  1. The Neon Madman says:

    In a normal house installation, the gravel footings under the slab have drain tile (basically, perforated tubing) embedded in them that collects tha water and routes it to the sump pit, where the pump ejects it. It would be nice to know if drain tile was installed when the slab was poured, and where it is so you can place the pit so water drains into it. Otherwise simply placing a pit with some openings for water may or may not work well enough. Original construction drawings would be what you want to find. Around here, code requires a sump pump in all new construction, has for years, so they are placed and piped when the concrete is poured.

    Good luck, I hope others have some worthwhile input.

  2. Ben C says:

    Typically (at least around here in MN) the sump basin is there to drain a perforated drain tile (plastic tube) that runs around under or just outside the foundation which acts to collect the ground water from around the structure into a central location for removal. If you can determine the source of the water, perhaps a sump hole where a spring is will correct the problem. But otherwise you won’t cover much area under the house with a single sump hole alone.

    Maybe going very very deep will allow a single hole to draw down the ground water in a small area? Not sure, haven’t seen that type of sump drain around here.

  3. Joel says:

    Typically (at least around here in MN) the sump basin is there to drain a perforated drain tile (plastic tube) that runs around under or just outside the foundation which acts to collect the ground water from around the structure into a central location for removal.

    Yeah, there’s nothing like that here. I was present for every stage of the slab preparation and pouring at Ian’s place, and I guarantee there’s no provision for ground water dispersion – because there isn’t supposed to be any ground water. So I’m going to have to compromise between the place where the water is obviously causing the worst problem and the place where it first shows up and can best be dealt with. I’m thinking a deeper than normal sump hole, at the place where it first shows up in the concrete and also can be best directed to the established drain.

  4. Pffft says:

    Does Ian’s house have gutters on the edges of the roof? Is that water being routed down a downspout and carried away?

  5. Joel says:

    Does Ian’s house have gutters on the edges of the roof? Is that water being routed down a downspout and carried away?

    Ian’s house is a concrete dome buried under lots and lots of sand. The only visible roof is over the porch, which is downhill from the main structure. So gutters won’t help.

  6. Joat says:

    Sort of in the same vein as the gutter comment, is there anyway the grading on the cover dirt that could be changed to help direct water away from the house.

  7. Mark says:

    Sound like digging a trench around the house and grading it to shed water downhill would do the trick?

    Keep the water from getting under in the first place?

  8. Jerry says:

    That it is happening now, in conjunction with the changes that have occurred in the wash over the last year or so, you might look there first? Doubtful your water table is that high, maybe there is a bar that needs to be sculpted? (if someone has equipment to help).
    Our river was flowing due east in its course one year. Swales in the field that connect it to a parallel stream system did not dry up. Our river course moved back to northward, hasn’t been an issue since.
    The other area to look would be uphill of the lar. Is there downhill flow that needs diverting? Lay a semicircle of perforated drain pipe around the lar to give it an easier path of least resistance?

  9. Ben says:

    I’m remembering that you mentioned some sort of new drainage/erosion problem on top of Ian’s cave. Could this be related? Could water that should drain off (and away from) the cave instead be running down around the structure and somehow infiltrating inside?

  10. Elrod says:

    Without embedded drainage tile, or associated sub-slab water-gathering paraphernalia, it sounds like the options are redirecting water flow (which, probably, will be of minimal effectiveness) and getting rid of water, which will probably work better.

    Meaning, putting in a well to drain the water table around the house and continualy pumping it empty during the wet season. That sounds like a lot of work. I wonder if local (or state) government has any Water Resource Engineers who might be able to help with research and solution design.

  11. chris says:

    All suggestions above are great but no one has mentioned the type of pump to use…. Get a float switch type, not a pressure type … I had the latter and the pressure port can easily get plugged and is a pain to check for operation… a float switch type is much simpler and can be easily checked… your local (for your definition of local) hardware or big box store will have them… Since the drum you have to set the pump into will probably be ported for piping you may have to drill a series of holes in the drum but then cover the outside with landscape cloth to allow water though

  12. Malatrope says:

    A lot of folks commenting here don’t seem to appreciate that the “house” is totally buried. There isn’t going to be any drainage tile being put around the foundation in the future 😉

    I have exactly the same problem, though in a more conventional daylight basement. Unfortunately, there was no waterproofing sheet of plastic put under the concrete and water comes right up through the cracks. The “ground” is solid, fractured rock. With a great deal of effort, I bored a hole big enough to sink a 5 gallon bucket with holes in the bottom into which I put a sump pump. It cycles a lot because the hole isn’t big enough, but it moves a lot of water out. Between that and re-routing the drain spouts away from the house, the problem became manageable (occasional damp instead of an inch of water on the floor).

    Short of excavating above the structure and putting a membrane and drainage piping in as a “roof”, and reburying it, I don’t see how you could change things except with one or more sump pump(s) around the floor. This is a pain.

    Flooding in the Arizona desert, who knew that was a risk. Unless it’s built in a wash, of course.

  13. plblark says:

    I’m spitballing here but here goes:
    Given that the structure is burried, the rain that falls may seep down and then follow the external structure and be channelled into the foundation.
    The comments on runoff changes “upflow” also seem like a good idea to investigate.

    We used a French Drain to solve our basement water problem.

    Both of these make the problem similar to our problem at our first house. The neighborhood was built over a dry creek in the late 1800s.There was NO drain tile, as the slab was poured over a dirt basement floor. Rain was following the landscaping and the walls to pool at the foundation and the path of least resistance brought it INSIDE in the basement in the form of a 2″ creek flowing from one corner to the other every time there was signifigant precip. Easiest solution was landscaping which doesn’t seem an option here. That only got us about half way there. The solution was a french drain which was essentially jackhammering and digging in a deep trench around the internal perimeter, putting un weep holes and then installing perforated corrugated pipe to channel the water to the sump pump in the low corner. then burrying and covering it with concrete. As you can imagine, there was considerable effort and expense involved ;-(

  14. Malatrope says:

    plblark, I considered that “around the floor perimeter” solution, but it didn’t work. The water was coming in because the general water table level went up in rainstorms. The entire floor area had the benefit of artesian pressure from below, driven by pressure from the hillside into which the house is built.

    If it gets worse, I think I might try what we did in Florida to keep the water table out of deep ditches when working on pipe runs: shallow wellpoints all along the sides. In my case, I’d only have to do it on the uphill side, essentially putting in external sump pumps every eight or ten feet. The same might be accomplished by a deep drainline flowing into a single pump, but it’s easier to bore well holes than to excavate a trenchline through the solid-but-fractured-and-porous rock.

  15. Ben says:

    To finish the thought from my earlier post, this is a new problem in a building that you said is some 12 years old, so look for a new cause! What has changed? I think that the erosion of the earth cover over the dome is a factor that should be considered. And yes, adding dirt over the dome requires equipment that you don’t have. (If you go this route, consider geotextile fabric, at least in strategic high-flow areas, if not all over the dome, to discourage further erosion and to reduce water intrusion.)

    A sump pump treats a symptom, but what caused the actual problem? Better to fix THAT if you can figure out what it is.

    If you do decide on a sump pump, then I like the idea that somebody had to use a float pump in a modified 5-gallon bucket. (Or perhaps one bucket on top of another to get a deeper well)

  16. Elrod says:

    Ben (above) may be on to something – what has changed? Is this year’s monsoon worse than previous years in which there was no water incursion?

    So, has the slab developed any cracks, perhaps hidden by floor tile ? Has the dirt under the slab settled enough to create passageways under the slab for water to follow? (That would take ground penetrating radar to examine, but that’s probably <$250, except perhaps more for the travel distances involved).

    There are companies who specialize in horizontal underground boring to insert utilities; one installed my internet cable under the street to get to my house – dig about a 4' deep hole, put the machine in it and it impact-drove a 2" diameter pipe under the street in sections, the pipe sections were pulled out, the cable run, the hole filled in. Something like that might work to put drainage routes under the slab.

  17. greg spera says:

    Pueblo Colorado dude here. I live in the Pueblo West area which is pretty dry most years. There was a two year stretch when my basement pumped a few hundred gallons of water a day. It was ground water about 8ft deep. If you dug a hole very deep where I lived it filled with water only during that period. In over 20 years living here there were 2 when the water table rose up that high. You just never know when weird things happen. Thankfully they put a perforated pipe below the foundation that connected to a plastic pit with a ejector pump installed.
    If your concrete has ground water outside of it, you will start finding evidence of Efflorescence. During those wet years the concrete looked like it had powdery white mold forming on it. If you brush it is dry salt.
    There are companies who can retro fit a drain system in a existing house. The way I’ve seen it done is either dig all the way around the outside and install from the exterior. Most people choose to do it from the interior. You saw cut the floor all the way around the perimeter inside the house. Dig a two foot deep trench. Install drain pipe and ejector pump. Fill in and pour concrete.

    The companies I’d use here in southern Colorado is Gagliano Engineering or Straight Line Construction.

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