Safe to dig beside foundation for drain tile placement 2

[Lawrence P]

Helping a relative install drain tile beside a leaking basement (and partial crawl). Intention is to dig directly beside the wall, cover in a waterproof membrane then place a French drain beside the footer. I'm a bit concerned (for them) about soil compaction and shifting once we disturb the soil near the footer. Looking for any insight.

 

[Lawrence P]

 

[Lawrence P]

 

[Lawrence P]

So water comes off the tracks in droves (second picture) due to water that flows onto the tracks from the street. The local municipality isnt cooperating as far as putting in storm runoff drains (this would fix the entire issue). The 1st picture is the bottom of the hill about 20 yards down from the tracks.

Our initial thoughts were a retaining wall with a french drain behind, a curtain drain (this is red line on the markup) and then a french drain inside basement-crawl.

We are likely going to put in a large swale right next to the tracks to divert water from that erosion point to a storm runoff area on the property. I'm thinking that the curtain drain may not be needed then as that the drain behind a retaining wall should now catch most of the water coming down the hill.

 

[oldestguy]

This the first time I have seen any info on "the tracks". Now we see there is substantial surface water problem, perhaps the main culprit after all. You might not even need basement footing drains if the surface water thing can be corrected. Perhaps walls and drains might be needed, but the main job is changing the surface grades to divert surface water WAY away from the building. Look into the possibility of having a small trench at the location of that yellow line, at the base of a bank and hopefully it is within he property limits. Paving the surface with asphalt "pavement" will divert a lot. If necessary a ground surface left there can be waterproofed using a clay layer and I mean real clay. Elsewhere in these forums I have explained on how to waterproof that surface with a natural volcanic clay bentonite. It has to be done very carefully or a real mess results.

Then after sufficient outside grade is changed a cut-off drain can be installed next to the basement. Follow with grading the surface and placing that sloped paving, etc.

This post should have been done about when the original question was asked, but missing important information really has wasted a lot of time here.

 

[Lawrence P]

Sorry by a "Cut Off Drain" next to the basement do you mean something sub-surface or are you talking about gutter drainage. And sorry I didnt mean to waste anyones time, I figured whether the water that was coming from the hill was exasperated by the track water or just natural water flow from the hill that there was still water subsurface that needed to be drained away.

 

[JGard1985]

@oldestguy


But then we wouldn't have a true Back of The Envelope Sketch.


Some great points raised by all!



Jeff
Pipe Stress Analysis
Finite Element Analysis

http://www.xceed-eng.com

 

[oldestguy]

My definition of Cut-off drain is a perforated pipe in a pervious fill in a former trench that collects seepage water from one direction in soil, so as to keep it from going in the other direction in soil. In this case the collected water that otherwise gets in the basement from nearby soil. That cut off trench (filled) is what I detailed with the drawing posted showing some protection for footing support soil.

 

[Lawrence P]

Thank you all for the help.