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Old 05-10-2010, 01:41 PM
 
Location: Grosse Ile Michigan
24,717 posts, read 59,563,864 times
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We have a pretty new basement (2006). We had them put in a drain system with drains on both sides of the foundation walls. The drains feed into two sump pits where the water is pumped out. We had them backfill with a couple of feet of gravel, then several feet of sand capped with about two feet of the natural clay (similar to pottery clay). For four years we had no problems. Now we suddenly have water coming in. We are working ont he cause, but it appears likley to be groundwater fessing up through the joint between the basement walls and floor.

THere are undoubtedly some people who know about this. I have several questions.


The contractor who is helping us wants to do thermal imaging. He says that this will unqeustionably show the source of the water intrusion. Is this accurate? Will it work if the water is coming from a broken pipe somewhere instead of groundwater?




If the problem is groundwater, what is the solution? We already have french drains under the slab and just outside the foundation wall. Would it work to jackhammer up part of the floor and install additional drains feeding into the sump pits? How difficult and costly will this be? The slab is reinforced with fiberglass mesh. I think that it is 4" thick.

trenching in from the top would be a nighmare. We would probably have to remove a concrete porch, a concrete deck, an ourdoor fireplace built on a block foundation that is about 4' deep. Removing the porch might require removal of the porch roof which is tied into the house roof. I think that getting at it from the outside is simply impractical.

Any ideas on where this water can suddenly be coming from? The area where the water is coming in has a concrete deck and is covered by a greenhouse like thing that keeps most of the rain out. It is near the pool, but the pool is not losing any water (except normal evaporation). The other part where the water may be coming from is covered by a concrete porch (slab on a block footing). I cannot understand how surface water is even getting into the ground unless it is flowing underground from some other location. If so, is there some way to find where the water flow is coming from and possibly intercept and drain that? (Ground Penetrating radar?).

The existing drain system is obviously working. The sump pits fill regularly and the pumps kick on several times a day except when it has been really dry. After a big storm, the water gushes into the pits and the pumps run almost constantly for several hours, then only occaisionally.

One other quesiton, what kind of expert/consultant do we need to find to come up with a good solution. Most of the water intrusion places seem to want to put a membrane inside or outside the basement which makes no sense. We need someone who will figure out how to get the water out of there. Making our basement into a big boat cannot possibly be the solution.
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Old 05-10-2010, 04:08 PM
 
Location: Somewhere in northern Alabama
16,838 posts, read 51,286,023 times
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You have done a fairly good job of describing the situation. Now it is a matter of applying logic.

Source of the water - I think you have effectively ruled out a broken pipe or the pool. If the water intrusion only occurs after a rain and dries up in between times, it is pretty rare to have a cold water pipe that breaks only during a rain. So we'll scratch those concerns off the list.

Your pumps are working. Where does the water from the pumps go? Does it go into a sanitary drain (unlikely) or a municipal storm drain, or is it just pumped out away from the house? Have you checked the other end of the pipe? Is the water coming out in a stream that matches the volume being put out by the pumps? If not, a joint may be disconnected or broken.

You can find out where the water comes from by using a dye. Stick some dye in the sump hole, then once it has been pumped out, watch to see if it comes back in. You may find pool stores have dye, or look online. The basic idea is covered here:

Dye tracing - Wikipedia, the free encyclopedia

My first guess is that water has found a return route from your leach field or sump emptying area back to the house storm drains and you are pumping the same water over and over. My second would be that the clay overlayer has been penetrated and water that used to be shed away from the house is now pooling near it (underground).

Is the water coming into the sump now muddy or clear? If it is muddy, you may have some underground voids or channels now.
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Old 05-10-2010, 04:29 PM
 
Location: Grosse Ile Michigan
24,717 posts, read 59,563,864 times
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We have not yet ruled out a broken pipe. We do nto see water running down the wall, but the block wall was damp in one location where I cut through the vapor barrier. However when I checked it later, it was dry. I am guessing that the dampness was caused by the block wicking water up from the floor, but maybe not.

WE cannot be sure that the water stops coming in when it does nto rain, because it never stops raining for long enough. It takes a few days for the sump pumps to slow back to "normal after a rain. Right now it is raining every few days, so it is hard to tell. If it was still cold , that might help. If the ground is frozen and no rain, but water still comes in, that would rule out surface water, and I expect leave a broken pipe or the sudden appearance of an underground stream.

I like that dye idea. One of the sump pumps discharges into a ditch 110 feet away from the house. The other discharges only about eight to ten feet away from the side of the house. That one would be the most likley cuplrit if there is a leak. That sump is near the water area and seems to run constantly, or at least more often that the other one. However part of the reason is that it is a different pump. It pumps a little out and then the float thingy stops it before the pit is empty. a few inches of water runs in and gets pumped out, and then it repeats. The other pump is a better brand and pumps the pit almost dry before it stops, so it runs less often. Thus it is hard to say which one is really pumping more water.


One other thing occurred to me. There is a slab ouside the carriage house that is about 10 feet from the corner of the house where the water seems to come from. When they dug out the footings for the slab, there was always a lot of water there. It would collect there after a rain and just never go away. (our ground is really really dense clay). They just dug out about three feet and filled the area with lots of gravel and then poured the slab. I wonder if water collecting in the gravel could somehow be migrating into the basement. the slab has a few cracks and shows signs of minor movement, but nothing substantial. The one thing that makes me think this has nothing to do with it is that there was a trench for utilities that goes right to that area and I would expect the water to follow that trench whcih goes to a different part of the basement where it is totally dry.

Last edited by Coldjensens; 05-10-2010 at 04:37 PM..
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Old 05-10-2010, 05:00 PM
 
Location: Dallas/Ft. Worth, TX
1,855 posts, read 5,670,655 times
Reputation: 3060
Quote:
Originally Posted by Coldjensens View Post
We have a pretty new basement (2006). We had them put in a drain system with drains on both sides of the foundation walls. The drains feed into two sump pits where the water is pumped out. We had them backfill with a couple of feet of gravel, then several feet of sand capped with about two feet of the natural clay (similar to pottery clay). For four years we had no problems. Now we suddenly have water coming in. We are working ont he cause, but it appears likley to be groundwater fessing up through the joint between the basement walls and floor.

It has been working well for four years and just now running heavily during rains. It is possible you have shifting underground streams that are now coming closer to the home.

THere are undoubtedly some people who know about this. I have several questions.


The contractor who is helping us wants to do thermal imaging. He says that this will unqeustionably show the source of the water intrusion. Is this accurate? Will it work if the water is coming from a broken pipe somewhere instead of groundwater?

Thermal imaging can potentially show where the water is entering the basement, and if there are excessively wet sections of concrete. However beyond that would take quite a bit of time to properly run thermal imaging to even guess what the actual source of the water is. It is useful but difficult to control under the circumstances of basement scanning. To find where it is entering, and if sections of the wall are saturated, should not take much scanning. After that then you would still need to perform some amount of destructive, or other, testing to find the actual source.


If the problem is groundwater, what is the solution? We already have french drains under the slab and just outside the foundation wall. Would it work to jackhammer up part of the floor and install additional drains feeding into the sump pits? How difficult and costly will this be? The slab is reinforced with fiberglass mesh. I think that it is 4" thick.

trenching in from the top would be a nighmare. We would probably have to remove a concrete porch, a concrete deck, an ourdoor fireplace built on a block foundation that is about 4' deep. Removing the porch might require removal of the porch roof which is tied into the house roof. I think that getting at it from the outside is simply impractical.

Any ideas on where this water can suddenly be coming from? The area where the water is coming in has a concrete deck and is covered by a greenhouse like thing that keeps most of the rain out. It is near the pool, but the pool is not losing any water (except normal evaporation). The other part where the water may be coming from is covered by a concrete porch (slab on a block footing). I cannot understand how surface water is even getting into the ground unless it is flowing underground from some other location. If so, is there some way to find where the water flow is coming from and possibly intercept and drain that? (Ground Penetrating radar?).

Ground penetrating radar (GPR) would be a better choice to start with both inside on the floor slab and walls, and outside around the home. Inside it can potentially tell if there are voids and water running under the concrete floor. GPR can potentially map anomalies behind the walls as well. Outside you can use it to map if any streams are running through your property. GPR is not cheap, but it would be my first choice under these circumstances, and I am a Thermographer but can't see the advantages over GPR for this problem.

The existing drain system is obviously working. The sump pits fill regularly and the pumps kick on several times a day except when it has been really dry. After a big storm, the water gushes into the pits and the pumps run almost constantly for several hours, then only occaisionally.

I know you said it has been running satisfactorily for the last couple of years but do you have a gutter system on the roof? Are the downspouts draining on the surface or do they enter drain into pipes running under the surface? Has this past year rainfalls been higher than previous years? It's a stretch but I have seen gutters improperly tied into the drainage system.

One other quesiton, what kind of expert/consultant do we need to find to come up with a good solution. Most of the water intrusion places seem to want to put a membrane inside or outside the basement which makes no sense. We need someone who will figure out how to get the water out of there. Making our basement into a big boat cannot possibly be the solution.

If it was my home I would find a very good, licensed Civil Engineer, versed in drainage, grading and residential issues. Have the PE come in first before you start spending a lot of money on testing, locating, tearing out, etc. The PE might surprise you and identify a relatively inexpensive correction. If nothing else they can advise you, after inspecting the area, what course of testing to take (GPR, Thermal Imaging, straight to coring) to check for water flow, etc.

I put some thoughts above in blue italics.
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Old 05-12-2010, 08:56 AM
 
Location: Grosse Ile Michigan
24,717 posts, read 59,563,864 times
Reputation: 26822
Quote:
Originally Posted by escanlan View Post
I put some thoughts above in blue italics.

Thank you.

We do not have gutters. However the area where the water seems to be coming in is covered in concrete (deck) with a greenhouse thingy that sheds most of the surface water off to the sides. The other potetinal area is a covered poch (concrete slab).

This years rainfall seems pretty typical, but we get a lot of rain this time of year. It rains several times a week. SOmetimes heavy.

I cannot determine whether it only runs during rains. This is the rainy season and it rains constantly. I thinnk that we would need four or five days with no rain before the water has all drained away. Right now we have several inches of water sitting on any low spots ont he ground. It drains slowly due to the heavy clay. It may not drain at all, maybe it just evaporates.

We have not found ant wet walls yet. One wall in the downer seemed damp when I first looked at it (I had to cut through the vapor barrier), but now it is dry.

It is difficult because the water comes out from under the base plate of the interior wall. I cannto tell if it is coming in somewhere else and just running along the edge of the wall under the base plate, before it comes out. We are trying to avoid ripping out all of the interior walls. We are already looking at thousands of dollars in repair/replacment costs. Not even including fiding the source fo the problem. We removed the bottom 2' of drywall and the base moldings, carepting and subfloor along one side, however the water seems to be coming from the corner. We hope to avoid any further drywall removal that might prove to be unnecessary.

i will look for a civil engineer and check into GPR. They said that the thermal imaging will cost $250. I imagine GPR will be more than twice that.
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Old 05-12-2010, 10:35 AM
 
Location: Dallas/Ft. Worth, TX
1,855 posts, read 5,670,655 times
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Quote:
Originally Posted by Coldjensens View Post
Thank you.

We do not have gutters. However the area where the water seems to be coming in is covered in concrete (deck) with a greenhouse thingy that sheds most of the surface water off to the sides. The other potetinal area is a covered poch (concrete slab).

This years rainfall seems pretty typical, but we get a lot of rain this time of year. It rains several times a week. SOmetimes heavy.

I cannot determine whether it only runs during rains. This is the rainy season and it rains constantly. I thinnk that we would need four or five days with no rain before the water has all drained away. Right now we have several inches of water sitting on any low spots ont he ground. It drains slowly due to the heavy clay. It may not drain at all, maybe it just evaporates.

We have not found ant wet walls yet. One wall in the downer seemed damp when I first looked at it (I had to cut through the vapor barrier), but now it is dry.

It is difficult because the water comes out from under the base plate of the interior wall. I cannto tell if it is coming in somewhere else and just running along the edge of the wall under the base plate, before it comes out. We are trying to avoid ripping out all of the interior walls. We are already looking at thousands of dollars in repair/replacment costs. Not even including fiding the source fo the problem. We removed the bottom 2' of drywall and the base moldings, carepting and subfloor along one side, however the water seems to be coming from the corner. We hope to avoid any further drywall removal that might prove to be unnecessary.

i will look for a civil engineer and check into GPR. They said that the thermal imaging will cost $250. I imagine GPR will be more than twice that.
I wasn't aware that your basement was finished off. In that case thermal imaging might be the way to start. It can help localize an area to start removing finishes. But can you describe how your basement is finished off?

You don't have gutters, you do have heavy clay soil naturally, you have standing water now and the water still comes in and the sump is running constantly. Is the grading around the home providing a sufficient slope away from the home to allow water to drain out? It is recommended that a 5% slope (6" drop in the first 10') for proper drainage.

We have heavy and expansive clay soil here as well. As long as the clay is compacted (undisturbed over the years) once it becomes saturated the rain just runs off quickly. I went back and read your original post and see you have 2' of gravel and 3' of sand below a 2' cap of local clay soil. What you might well be seeing is water making it down to that 5' of great water filtration material that just allows it to pass through to the drain below. If your grade around the home is not sufficient, and you have heavy runoff from the roof, you could have water standing near the foundation, passing through easily to the drain below. I would definitely speak to either a drainage professional and/or Civil Engineer specializing in drainage. I would also consider guttering, along with proper grading, to help keep water away from the home.

Last edited by escanlan; 05-12-2010 at 10:51 AM..
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Old 05-12-2010, 11:55 AM
 
5,019 posts, read 12,466,511 times
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No advice, just my deepest sympathies.

I just came up from the basement, and behold, your thread.

Guess what I was doing? Yep, shop-vac-ing, squeegee-ing and mopping the basement. For the second time in 24 hours. I don't think my basement floor has been this clean in 2 years.

Luckily (?) in our case the cause is obvious---we are under construction and all of our careful grading work is currently "un-graded".

Those "mystery water" problems are always the worst. Good luck.
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Old 05-12-2010, 03:30 PM
 
Location: Grosse Ile Michigan
24,717 posts, read 59,563,864 times
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The insurance company sent a plumber who performed a very scientific test. He tasted the water and declared it to be ground water.

Still waiting for the thermal imaging guy. Still looking for an engineer.
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Old 05-12-2010, 03:35 PM
 
Location: Grosse Ile Michigan
24,717 posts, read 59,563,864 times
Reputation: 26822
Quote:
Originally Posted by escanlan View Post
I wasn't aware that your basement was finished off. In that case thermal imaging might be the way to start. It can help localize an area to start removing finishes. But can you describe how your basement is finished off?

You don't have gutters, you do have heavy clay soil naturally, you have standing water now and the water still comes in and the sump is running constantly. Is the grading around the home providing a sufficient slope away from the home to allow water to drain out? It is recommended that a 5% slope (6" drop in the first 10') for proper drainage.

We have heavy and expansive clay soil here as well. As long as the clay is compacted (undisturbed over the years) once it becomes saturated the rain just runs off quickly. I went back and read your original post and see you have 2' of gravel and 3' of sand below a 2' cap of local clay soil. What you might well be seeing is water making it down to that 5' of great water filtration material that just allows it to pass through to the drain below. If your grade around the home is not sufficient, and you have heavy runoff from the roof, you could have water standing near the foundation, passing through easily to the drain below. I would definitely speak to either a drainage professional and/or Civil Engineer specializing in drainage. I would also consider guttering, along with proper grading, to help keep water away from the home.

It is finsihed just like any other part of a house, except we used modern materials. The room is one of my daughter's bedroom. 2x4 stud walls, fiberglass insulation, drywall. The wiring and heat are pretty much the same. THe floor is chipborad squares on plastic feet (from home depot) for subfloor with padding and carpeting. It is going to be expensive to replace. There is a bathroom nearby, but we ruled out any leaking form the bathroom. No plumbing pipes in the walls where the water is, but there might be some in the walls on the next floow. Thee is a hose spigot not too far away. But then the tast test determined that this is ground water.
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Old 05-12-2010, 05:20 PM
 
Location: Dallas/Ft. Worth, TX
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AAHHH, the highly techical "Taste Test" method. That is a really expensive test method too I would expect? That was funny!

Yes, Thermal Imaging might be a good place to start with the way the finishes are. Once the Thermographer narrows down the potential entry point area you can move on from there with removing that finish first.

Keep us posted on how this progresses as it is interesting, sad to say.
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