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Help with french drain against foundation, negative slope

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andyl9063

Computer
Jan 9, 2020
13
I had some water intrusion issue.
Plan is :
1. 2 layers of waterproof membrane
2. 1 Drainage dimple mat
3. Mat sits on drainage pipe
4. Cover pipe with 2 layers of sock, then fill with sand on top
5. Backfill rest with clay soil.
The issue I'm running into is the last part of foundation has a 12 inch drop so drainage pipe has a 12 inch drop. The red circle is day-light that I could drain out to, but its 12 inch up hill.
I know there will be a way for water to go out, but would it struggle uphill and water sitting there near foundation with perforated holes.
Is there another solution? Or I was thinking of a catch basin with a lower inlet and higher outlet that drains out to daylight? Will that work ?
Capture_newhev.jpg
 
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I'm not sure why the 'overkill' on drainage. If done properly, a single layer of waterproofing is sufficient, and a good product should be used. Drainage 'dimple mat' is excellent, and I've used it numerous times. A single sock, provides adequate coverage, and I would suggest that your backfill over it should be clean 1" crush or something similar, isolated from native soil with a geotechnical membrane. Add proper slope to drainage outlet.

You don't need to 'double up', you need to do it properly. [pipe]

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
Hi,
This is my 2nd time doing it. I want it to be bulletproof and never have to touch it again.
The issue is my drainage outlet. It drops at the end about 12 inches and has to go back up hill for daylight.
 
The real secret is to do it correctly the first time. Are those tree roots? That can be a real trouble maker. I don't usually refer to that as a French drain... just a foundation wall drainage. It's tricky to get water to run uphill; another method has to be considered. This may require a sump pit and sump pump if you have lots of water.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
No, that is just rose bush. I'm trying to avoid a pump so is there another solution?
What about a pit, if it goes to the pit and gets full, will it go back through the perforated pipe?
 
If you have that much water, then the pit will likely fill without any help from the drain. Once the pit is full, the water will maintain that same 'full' level through the entire system. It is likely that to do this correctly, you will need a sump and a pump. If ground water then you have little choice. If surface run-off, you can try to lessen the water going into the system by means of drainage and impervious soil.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
We need some comments from others that are more involved with site work and remediation. I occasionally do this work, but it's not my main engineering stuff.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
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