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Discussion Starter · #1 ·
Where does the drain tile go for a monolithic slab foundation?

My contractor built a 10 inch ledge on the exterior side of the foundation wall for some reason, and the drain tile was installed there. Now we have a big leak problem at the bottom of the wall, at slab level, and no where else. Is the position of the drain tile part of the problem?

Where is it supposed to go?


I thought it was supposed to be buried further down near the bottom of the mono slab. But the surprise ledge makes this problematic ....

Any one know?
 

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Water seeks it's own level.

The drain tile always goes below floor level. Your contractor, your architect, and your code enforcement officer should have picked up on this.

If you have a large quantity of good porous backfill, it will gather up LOTS of water and channel it right into your basement.
 

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Doh!

Somehow seal the foundation and slab joint, or dig out the outside foundation wall down to the footer and install drain tile and run it out to lower ground, or inside to a sump, or cut the perimeter of the slab and install drain tile and run to sump.

-any other ideas?
 

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J Hague said:
My contractor built a 10 inch ledge on the exterior side of the foundation wall for some reason, and the drain tile was installed there.
????? At what height, relative to the top of the floor slab, is the top of the 10" ledge? Does the drain tile lay on top of the ledge?

J Hague said:
thought it was supposed to be buried further down near the bottom of the mono slab.
At what depth, relatiive to the top of the mystery slab, is the botttom of the floor slab?

At this point, are you able to uncover the drain tile in its entirety?
 

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Discussion Starter · #5 · (Edited)
PipeGuy said:
????? At what height, relative to the top of the floor slab, is the top of the 10" ledge?

exactly the same.

>>Does the drain tile lay on top of the ledge?

Yes, that's what they tell me.

>>At what depth, relatiive to the top of the mystery slab, is the botttom of the floor slab?
Mystery slab...hmm... not sure what you mean ...
I am told by the w-proofer that there was a 10 inch ledge of concrete on the exterior side of the concrete block wall where they set their drain pipe. This probably was caused by an overly large shovel being used to scrape the foundation hole.

So... the ledge on the outside of the wall, is merely a continuation of the slab on the inside ... all the same elevation ...

And I don't mean to lead folks to an answer ...but it seems to me that the worst place to put the drain tile would be on that ledge ... that's like sucking the water to the vulnerable crack between block wall and mono slab foundation.


>>At this point, are you able to uncover the drain tile in its entirety?

Yes we can uncover this in its entirety.... well that is of course if I can get contractor and sub to agree to the remedial measure....

------------------

Another Q.... How many stories can I have on top of this kind of foundation, monolithic slab? I always thought these foundations were only good enough for one story ... like a garage ... but this is a stair tower...
 

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I've seen many drains installed as you describe without complication.

First off, the foundation drain needs to empty somewhere - preferably to daylight. It should be layed down so that water does not 'pond' inside the drain.

The fact that you have water penetrating the joint between the block and slab, while having a drain tile immediately adjacent to the joint, indicates that either the drain isn't emptying properly or the joint is exceptionally un-watertight. If the drain was working I doubt that water would penetrate an otherwise intact joint between the block and slab.
 

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Without being able to see your project in person it is impossible to say what is going on for sure. But I guarantee you one thing, the root of your problem is simply this: WATER SEEKS IT'S OWN LEVEL. Does your contractor have a problem with this concept?
 

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Discussion Starter · #8 ·
Shallow foundation adjacent deep causes leak?

Now they are saying that because there's an adjacent shallow foundation next to this 8 foot deep one, that the water is finding its way in.

Now let me try and give you a picture....
A 40x30 one story house was built with a full basement around 1940. Later on a front porch was added, with, of course, no basement, just a crawl space. After that, the front porch was enclosed to be part of the house. Now today in the next century, add a stairwell from original 1940 part of the house to the basement. Put it outside of the footprint of the house. In this case, put it on the right side of the house as you look from the street.

Slope the backfill from 2 feet below main floor of house down to back of daylight basement ... and voila ... you'll see about 4 foot deep of backfill on the stairwell.

That street side of the stairwell, is the upstream side of all water run off and underground pressure (we are last stop before the creek in the back yard, for underground water).

So now question the waterproofers theory that the water showing up between the block wall and slab, 4 foot below outside fill) ... is water which has found its way through the dirt to some -un water proofed surface to come into the stairwell.

Have I made a good picture? Does it make sense? What about their theory?

Thanks!
 

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...What about their theory?...
WATER SEEKS IT'S OWN LEVEL.

I guaran-freakin'-tee you that, regardless of where you are located on this planet, you can safely treat this "theory" as if it were a fact.

Hire someone who does.

Best regards,
 

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Discussion Starter · #10 ·
mikesewell said:
WATER SEEKS IT'S OWN LEVEL.

I guaran-freakin'-tee you that, regardless of where you are located on this planet, you can safely treat this "theory" as if it were a fact.

Hire someone who does.

Best regards,
Mike --
The upstream side of the 8foot deep foundation does not leak, and has not leaked. But the matching upstream side of the 8 foot deep foundation wall that they just built, does leak.

How can they say that it's because of the old foundation, that the new leaks? How can you say their "theory" is correct? The old one doesn't leak, and it is adjacent!
 

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Discussion Starter · #11 ·
mikesewell said:
Water seeks it's own level.

The drain tile always goes below floor level. Your contractor, your architect, and your code enforcement officer should have picked up on this.

If you have a large quantity of good porous backfill, it will gather up LOTS of water and channel it right into your basement.
My archi, did .... but the dear contractor did not build what was designed.... he wanted to save money by doing the small pour of fdn and slab all at once , you see, and did not ask .........

then somehow, when the inspector came around ... he said there were no drawings...so he just "inspected" whatever was in place .... How did he do that? How did he manage to inspect a monolith slab below grade and make it pass????? And where did he think the drain tile was supposed to go?

And then why is it that subsequently the proper inspection for the drain tile was omitted and no one is blowing a whistle? and the inspector is not now making the contractor uncover what was put in place ..especially now that it is leaking ...

??? But how did the inspector manage to skip the drawings which I had just put in the box again for him 30 min before he was there? I kept finding the drawings not in the box that day ...so I would find them and go put them in the box again..... grrrrrrrrrrrrrrrrr

and d*it...why didn't he ring the doorbell?? I stayed at home that day for the inspection .... I worked in the adjacent room all the day before and 3 hours that morning to see what happened....then for 1.5 hours I worked at the other end of the house ... had to ....... and neither contractor nor inspector let me know the inspection was on ,,, and that the pour was happening ....

Contractors wonder why owners hover on their shoulders ...... this is WHY!
 

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J Hague said:
...How can you say their "theory" is correct?...
THIS theory is correct:
WATER SEEKS IT'S OWN LEVEL.

To a competent excavator, contractor, engineer, architect, or building inspector, this makes everything else about the job CHILD'S PLAY. This is KINDERGARTEN ENGINEERING. Collect the freakin' water and put it someplace. End of Story. If any of the above named people spend more than about 2 micro-seconds thinking about how to handle this situation on a residential job, have them executed by firing squad immediately before they pollute the gene pool.
 

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inproper installation

I no what your talking about. Your talking about a perimeter draining system which is located around fondation wall under the soil. The whole purpose of this is to drain excessive water away from the foundation to keep basement nice and dry. The contractor must have installed it incorrectly MAKE HIM FIX IT. Get a independent second oppion. You should have never allowed him to cut corners especially when it comes to something a serious as foundation and perimeter draining system. As norm abrahams of this old house would say "keep the water away from the house and it will last indefinately. :Thumbs: I just watched then meaning this old house install a perimeter drainage system on there new project. Its all in the preparation. Something your contractor failed to realize. LET ME SAY THIS AGAIN GET A INDEPENDENT SECOND OPPION AND MAKE HIM FIX IT!!!!!!!!! :Thumbs:
 

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747 said:
...MAKE HIM FIX IT...
Nein, nein, nein! Don't let him touch that, or anything else. See #1!

The water in your basement is proof beyond a reasonable doubt that your contractor doesn't understand that WATER SEEKS IT'S OWN LEVEL. Hire someone who does.
 

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747 said:
The contractor must have installed it incorrectly MAKE HIM FIX IT.
I'd go one step farther by saying that if the contractor as much as blinks about fixing it I'd just go ahead and 'make him bear the cost' of having someone else fix it. I tend to agree with Mike that he may noy be qualified to fix the problem if, in the first place, he didn't understand the concept of head pressure.


747 said:
You should have never allowed him to cut corners especially when it comes to something a serious as foundation and perimeter draining system.
I must have missed the part that indicated the owner's complicity in the corner cutting. In a job like this it's not the owner's responsibility to assure the application of proper means and methods for construction.

I still think, based on what's been said, that this problem is as much a construction joint issue as it is a drainage issue.
 

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you guys are correct

I didn't read carefully the first post. I would like to add however on this old house current project when they installed the perimeter drainage system around foundation they had Roger Cook their landscapping contractor install it. I absolutely agree. I wouldn't let the contractor who originally put it in try to fix it. :Thumbs:
 

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747 said:
...I wouldn't let the contractor who originally put it in try to fix it...
I agree. It just doesn't work. Get a competent contractor in there.


Pipe said:
...In a job like this it's not the owner's responsibility to assure the application of proper means and methods for construction...
You are absolutely right. It is however, the owner's responsibility to select a responsible contractor in the first place. :eek:

Pipe said:
I still think, based on what's been said, that this problem is as much a construction joint issue as it is a drainage issue.
Without being on site, I can't agree or disagree with you on this point, but I will say that a bad construction joint shouldn't be allowing too much water to pass, unless there is some other problem as well.
 

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J Hague said:
Where does the drain tile go for a monolithic slab foundation?
Mike Finley said:
Somehow seal the foundation and slab joint, or dig out the outside foundation wall down to the footer
J Hague said:
Now they are saying that because there's an adjacent shallow foundation next to this 8 foot deep one
J Hague said:
a front porch was added, with, of course, no basement, just a crawl space.
747 said:
Any person who is thinking about going with a monolithic foundation should really check this company out.
Not being a builder, I'd like to have a better understanding of how some building terms are used in this post and what they describe. Will you guys be kind enough to clue me in?

In the first post I see the term "monolithic slab foundation".
Subsequently I see the terms "foundation and slab joint" and "foundation wall".
The original poster also goes on to describe an "adjacent shallow foundation" next to the "8 foot deep one".
I also learn that the porch is on a "crawl space"
Lastly I get info on a precast "monolithic foundation" system.

Here are my questions:
Is a 'slab' foundation the same as a below grade structural slab?
If a structure has a slab foundation, does it also have foundation walls?
How is the slab foundation 8 feet deep (next to the shallow foundation)?
Is a crawl space a type of foundation?
Is an assembled precast panel system considered a 'monolithic' system?

I was under the impression that a 'foundation' wall was a wall that had no adjoining occupiable space - that it was entirely below the inhabitable structure. What is it that puts the 'foundation' into a foundation wall?
 
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