French drain not working so good?

[BeachyT]

My 50 yr old basement has 2 modifications to it in order to prevent water seaping in. 1) a pipe system. 2) What appears to be a cut in the floor about 12 inches from the wall.
The pipe system consists of a 1/2 black or copper pipe around the perimeter of the basement. Every 6 to 8 feet the pipe extends into the basement wall, don't know how far. The pipe then runs to a sub pump and is evacuated to the outside away from the house. The system looks old and still works to some degree.
The cut in the floor is something else... I don't know if some other type of drain is in place, BUT this is where the water is seaping into the basement FROM THE CUT.
Any suggestions on how to repair or improve the system(s) to elevate the water problem TOM

 

[Focht3]

Someone tried to install a "french drain" after the basement was built - hence the floor cut. (It's really a sub-floor drain.) And the sub-floor drain isn't working. The only way to fix it will be to figure out why it failed. There are no pat answers.

Does the floor cut lead to your sump? Can you see a pipe entering the sump from below slab level? Is it "making water"? Do yo have sand/silt/clay in the bottom of the sump?

We need much more information if we are to offer you anything really useful -



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.

 

[BeachyT]

The floor cut does NOT lead to the sump, which is in the middle of the basement. I can't see any pipes entering the sump below the surface. No build up of sand/silt/clay.

1) Maybe they never completed the sub-floor drain?
2) The water that is pushing up through the floor... could it be under preasure?
3) If I excavate a small area would this relieve the pressure in other parts of the floor?
4) The sump is old...are they perferated?
5) Would replacing the sump help?

 

[Focht3]

I assumed the cut went all the way around the basement - is this correct?

I wouldn't break into the slab just yet - you may create a REALLY big problem that way....

Replacing the sump will only help if the sub-floor drain leads to it, and the sump isn't taking the sub-floor drain's flow.

Do you get much discharge from the 1/2 inch copper lines?



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.

 

[BeachyT]

The cut in the floor defintely goes around 3/4 of the basement... the other 1/4 is a little hard to see,,,but i'm going to check

The 1/2 pipe does discharge ... i'll guess half gallon/min
during a heavy rain, but thats relative to the amount of rain that I get... I'm not sure if the pipe is clogged somewhere along the line.

It seems to me that my first option would be to replace the pipe with PVC. Not sure if I should increase the diameter. The part that goes into the basement wall,, should it be increased?... is it perferated?

 

[Focht3]

Have you quizzed the previous owner? Talked to any of your neighbors? I'd explore as many avenues as possible before I started tearing stuff up. That is, unless something is about to fail...



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.

 

[BeachyT]

Previous owners wherabouts unkown. I going to investigate replacing the pipe.

Do you believe I will create a bigger problem if i remove a 1 by 1 ft section to see whats below?

 

[Focht3]

That's very risky...



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.

 

[BeachyT]

Can you suggest any concrete patching material that I should use?