I have a problem where water actually "comes up" from under the slab of my basement into the trough (the groove along the wall) in the corner of my basement that is caddy-corner from the sump pump.

I have soaked up the water in the trough only to see it rise up, seemingly coming from under the slab. (It does not seem to be coming from the wall itselft).

The sump pump is fairly active, but I have it set fairly agressive so that there is less than 1 inch of water at any time in the 18" deep pit.

If I leave the pump off for extended periods of time, the water will sit _no higher_ than 6 inches below the slab...so the water level under the slab shouldn't be a problem...should it?!

I am thinking about installing another pit/sump in this corner to resolve the problem.

How can water be coming up if the water level seems to be well below the slab?

Is installing a second pit/pump a good idea?

Thanks!

When you describe the "trough", do you mean a channel that was either built-in or placed later to direct water to the sump? Or simply the joint between the slab and the wall, where builders typically place a joint filler of about a half-inch in thickness?

And does the water come up constantly, or only after or during a heavy rain?

Regardless of the answers, a sump and pump in that area seems like a good idea, and I can't think of any reason not to do it.

I'm reminded of an office bulding I designed over 30 years ago, which had a small basement. I set the basement floor a foot above where the test borings showed the water table to be, and designed in a sump just to be safe. During construction, the sump filled with water up to an inch from the top after a rain, and then the water receded. (We had not installed the pump yet)

At the last minute the Owner asked us to have one elevator go to the basement, so we put in an elevator pit four feet below the basement floor. The contractor reminded me that a sump in the elevator pit would not be a bad idea, so we put one in.

The sump in the elevator pit has been dry to this day. The one in the floor four feet higher still gets water to within an inch of the floor, and not a drop more. Go figure.

(Actually I know why, but the answer will take more space than might be available!)

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Or simply the joint between the slab and the wall, where builders typically place a joint filler of about a half-inch in thickness?

Yes... I meant the joint (gap?) between the slab and the wall. Thanks for the thoughts!

I have some water pressure outside of the cement blocks on this same wall. The dampness/scattered bleeding goes up approximately a brick and a half. Just this weekend I applied hd150 to the bricks. I can't get at it from the outside because it is under the garage. Theoretically, the water pressure under the slab is isolated from the water outside the foundation walls, correct? Otherwise, the water would have already risen above the joint/gap along my foundation walls since the dampness/bleeding is several inches above the basement floor. I am kind of concerned that when I dig the hole for this pit, that I'll have some sort of water rush that can possibly flood the basement (if the sump fails)...whereas although I currently have a wetness problem, I do not have a flooding problem. Sound right/other thoughts?

hamm3r,

whoa.....IF you Only have water coming up through'cold/isolation joint' which is where the bottom of bsmt wall `n floor meet, that does NOT 100% define that your problem is under the bsmt floor. Many homeowners have water that comes out onto floor at the cold joint, and 90% of the time it IS because there is an Outside problem/opening in the bsmt wall...on the outside of where you see water inside. Now, that 10% could be YOU, sure...you may have a blockage-clog under floor in that area, but to put another sump in when your NOT sure exactly what the problem is may mean you will waste money on something thats NOT going to solve your problem...right?

Run a hose on the outside of where you see water inside...yep-in the garage---run the water at ground level and let it soak that area for up to an hour...or until you get water in. IF...you get water in then your problem will be the bsmt wall. And hey, no one should have 'gaps' --openings at the cold joint, that ALONE Can allow Radon gas to enter your home!

Is your home built in high water table area? Is the 'very-bottom' of your...lolol....Bottom course of block-wall(first from floor)...BELOW the bsmt floor?

I`d...do the hose/water test....if NO water comes in--up through the cold joint then, IF you have a 'Storm trap' have a plumber SNAKE through it! Many times this IS the homeowners problem.


Now, if after running the hose FULL blast and you had no water come in(dont forget Above-ground openings which can allow water into block bsmt walls and onto floor at Cold-Joint), and then you had plumber snake through storm trap, and on next rain still get water in..THEN i would look into another sump.

You can fix a crack/problem with bsmt wall UNDER garage floor, saw cut 18" x whatever linear footage is needed and after waterproofing, replace small concrete 18" apron, we do it all the time. opinion gl!

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Run a hose on the outside of where you see water inside...yep-in the garage---run the water at ground level and let it soak that area for up to an hour...or until you get water in. IF...you get water in then your problem will be the bsmt wall.

It's been about 2-3 weeks since our last real rain (and it was the 8-9 day heavy rain period we had in the Northeast, US) and water is still coming up through the gap...even without running the hose..so unfortunately it doesn't seem like I can try this great test

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Is your home built in high water table area?

I am conflicted/confused over whether I do or not. On the one hand...the wall with the problem looks like it has a water level that extends about 1-2 inches above AND below the bottom course. (note that to a varying degree...it is dry BELOW the water mark I described...EXCEPT in the front corner of the house where the water is coming in from under the slab.)

On the other hand...I live on a fairly level plot, and the opposite wall is fairly dry (some previous evidence of efflorescence) AND if I shut the sump off indefinitely, I have 9 inches to spare in the sump pit...Does this water level represent the water table?

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Is the 'very-bottom' of your...lolol....Bottom course of block-wall(first from floor)...BELOW the bsmt floor?

It seems as though the bottom course is set even with the bottom of the gap between the slab and the wall. I just measured from the bottom of the gap to the top of the bottom course and it measures 8 inches.

Just to further confuse the "high water table" question: The house immediately next to me on the "dry" side of my house has a water problem. He had the internal water solution put in and has 3 sump pumps.

The house on the wet wall of my house has an unfinished basement that is completely dry. No water in sump.

The house across the street is also completely dry...

I don't have measurements or anything...but from my untrained eye...all of my neighbors houses seem to be at the same elevation as mine.

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I`d...do the hose/water test....if NO water comes in--up through the cold joint then, IF you have a 'Storm trap' have a plumber SNAKE through it! Many times this IS the homeowners problem.

Sorry for the ignorant question...but what is a storm trap (I know what a plumbing trap, in general, is) and how do I know if I have one?


I can't tell you how much I appreciate your help! The house is only 12 years old and I lived in it for 3. The previous owner was "nice enough" (for clarity...I am being sarcastic) to patch the walls with hydraulic cement and Drylok, then finish the basement. I've ripped the problem wall down. The "sump room" (actually the furnace room) is caddy corner to the problem wall and is unfinished and pretty dry.

Hamm,

ok, hasnt rained for 8-10 days, still.....doesnt mean that there isnt an outside cracks-problem. Water can build 'Inside' the cells/cavities of a blcok wall after it has entered through a crack on the outside. Sounds strange to some but i`m serious...one would think any water that gets Inside a block wall will enter onto the bsmt floor but, Not Always. Like i said, you still may or may NOT have an outside opening(s), running water would tell ya.

But as i say that AND you replied it has Not rained for awhile, sure.....your problem may indeed be a blockage....under the floor in that 1 area. It`s just that almost-Always when there IS a blockage/problem Under the floor and NO Outside crack-problem that most homeowners will say that they see water coming-UP through cold joint in..Many places along several walls or ALL walls, NOT just 1 area of 1 wall...know what i mean? lolol

There have been a few unlucky homeowners who have had a leak-problem with their water-line, and will have/see seepage in 1 area, could YOU have the same? Is your last water bill normal or ya notice an increase? How about a sprinkler line, any possible problem/leak with that?

Patching the wall(s) on inside with anything will NOT solve an OUTSIDE problem/crack etc. It also can hide-conceal any visible problem/crack that one could have seen BEFORE this was done to wall.

I`ll say again, with a crack or other outside opening(s) many times homeowners will ONLY see water at the cold joint, they will Not see any water anywhere on the bsmt wall, will not see dampness on the wall, Only water coming from cold joint. Unfortunately sometimes it can be hard to distinguish what the actual problem is from on 1 home to another,thats why i say Never Assume what the problem is when in-doubt, and to run water test and snake etc first. Maybe find a good experienced-honest plumber, have him snake through Anyhting first to see if that helps/solves problem and pick his brain about his thoughts on your sump pump. Sure, in the end you may need another sump IF the problem is....Under the floor.

I wish i could give you-others the 'exact remedy' but thats Not the way it is with basement waterproofing `n leaks-seepage problems in basement. There are several possibilities and never good to assume, all i can say is that most...not ALL, peoples problems around here, about 90% are from Outside openings and there are many companies/contractors who love to bllchtt people outta their money.

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ok, hasnt rained for 8-10 days, still.....doesnt mean that there isnt an outside cracks-problem. Water can build 'Inside' the cells/cavities of a blcok wall after it has entered through a crack on the outside. Sounds strange to some but i`m serious...one would think any water that gets Inside a block wall will enter onto the bsmt floor but, Not Always. Like i said, you still may or may NOT have an outside opening(s), running water would tell ya.

Sorry for the miscommunication...what I meant was that although it hasn't rained for 8-10 days, that water was STILL coming up. So if water is already coming up BEFORE the hose test I'm kinda screwed. Wouldn't I have to wait until the water stopped coming up in order to run the test?

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But as i say that AND you replied it has Not rained for awhile, sure.....your problem may indeed be a blockage....under the floor in that 1 area. It`s just that almost-Always when there IS a blockage/problem Under the floor and NO Outside crack-problem that most homeowners will say that they see water coming-UP through cold joint in..Many places along several walls or ALL walls, NOT just 1 area of 1 wall...know what i mean? lolol

Yes, I understand...

quote:

There have been a few unlucky homeowners who have had a leak-problem with their water-line, and will have/see seepage in 1 area, could YOU have the same? Is your last water bill normal or ya notice an increase? How about a sprinkler line, any possible problem/leak with that?

Interestingly enough, this IS the corner that has the water pipe and waste pipe coming through...altough the water is coming up from under the wall that does NOT have these pipes. Still, the pipes are very close to the corner. Last year, my dad and I dug up the outside on the wall with the pipes (the garage is over the other wall) and we sealed around the water pipe with that "Great Stuff" foam product. It wasn't until we buried it all up again and tore down more of the wall that was saw the waste pipe going through the wall. And YES there are signs of water coming through the wall where the waste pipe goes through!

Also, I can't say for certain that we were able to get the water pipe (which is maybe a foot lower than the waste pipe) to be perfectly sealed.

So water can be getting into the cement block hollows and leaking out the cold joint on the other (very nearby )wall? If so, what/how do you recommend sealing the waste pipe? Should/could it be done from inside? Should I call a plumber?

I don't think it is a leaky water main. During this summer's dry spell, the water in my basement dried up.

Hamm,

sure sounds like that could be it, i`d find a good/honest plumber.

We have had several homeowners have a leak on the floor right at the cold joint, coming from only 1 area where the wall `n floor meet. Turned out that where the sump pump pipe went through the wall to outside had a hole in it, hole being inside the blcok wall, so it continually dripped 'inside' the cells of wall and only came out at cold jt. Water lines too!