[rossfingal]

Hi All!

We're digging out and waterproofing a foundation wall (3 1/2 to 4 feet down).
We discovered no drain-tile on the back of the building, so we're going to
add it (with gravel).
We have to tunnel under a 3 ft. to 4 ft. stoop/sidewalk, just replaced last
year - so we would rather not bust it out!
We're going through clay (luckily, few stones).
I've done this before for electrical runs (that was fun!) - but, this is 6 inch
drain tile!
Advice, suggestions!?! (Condolences!).

Regards!

rossfingal

 

[rjniles]

Personally I would cut a slot thru the concrete a wide enough to use a small backhoe to dig the trench. digging down 4 feet in clay by hand would not be an option for me.

If you are adamant of not breaking up concrete, dig a pit on either side and dig under the sidewalk with a hard-bar and a trenching shovel. Keep the hole as small as possible so the concrete doesn't cave in.

 

[gregzoll]

The only way around it, is to cut the concrete at the expansion joints, remove that section, then do the digging. Be careful, even at 4 feet, you can have a cave in from the dirt sidewalls.

 

[rossfingal]

Thanks to both of you (rjniles) and (gregzoll) for your responses!
The slab we would have to take out is about 4. ft by 3 1/2 ft. - I took out
the old slab and put in new "crete" last year - (along with all the sidewalks - 250 to 300 bags, 60 lbs./bag).
If it was up to me - I would take out the slab - big deal: some sledge-hammer work, and bags of sakrete - no problem!)

I'm not the one who determines how the money is spent!
(If you can get my "drift")

We've already dug out some of the building - not much chance of a
"cave-in" - (of course, thanks for the warning!).
(I've had the "pleasurable", experience of excavating - 14 ft. down, bad soil - install sewer mains, manholes {2} - now that's fun -
nice Thanksgiving celebration!!)
Thanks again!!

rossfingal

 

[rossfingal]

Okay, how about this idea!?
A friend of mine suggested - renting a "two-man" auger, and using it for
initial excavation.
To, kind of, open things up, and make the hand-digging easier.
Any thoughts?
(I know, we'll have to angle it)
Thanks!

rossfingal

 

[linuxrunner]

We used this method when we installed our water main under our sidewalk, obviously a different size pipe, but i would be willing to bet it would still work.

dig your trench on either side of the walkway. Start with a 1-2in steel pipe and began hammering it through from one trench to the other (under the walkway). Anytime it seems like it just won't go any further stop and put in a metal pipe with a hose attached to the other end, leave it in there and really soak the soil.

You can then go back to the sledge and the 1-2in steel pipe. Once you are through to the other side, step up the pipe diamater and go again (the first is the worst).

It's slow and takes a lot of effort, but i know its possible. :yes:

 

[rossfingal]

Thanks "linuxrunner"!
That's how I've run electrical!
I was just hoping somebody had "tips or tricks" to make it a lot easier!
(I wish it wasn't 6 inches wide - Ouch!)
Thanks again!

rossfingal
(Sounds like - "digging are us")

 

[jcrack_corn]

dude...clay...really? are you sure? clay (in the south) is something you hit with a very heavy shovel and get a couple of pebbles to break loose...the stuff to break a mans will.

i woudnt even consider this...rent a mini-ex and do the whole job in an hour. for real.

repouring 16sqft of concrete is not even a consideration....you can do that in the afternoon. (what, 4" thick slab? thats 6 cuft with waste, thats like nine 80 pound bags.. or 30 bucks.


(and ive rounded everything up!).

am i missing something?

 

[rossfingal]

"jcrack corn"

No, Mr. "Corn" - you're not missing a thing!
I know, I know - I don't specify - I just implement!
(Well, I do specify - but, everything is taken into consideration)
Apparently, and this was brought up; renting a machine, is not an option!
Oh well!
Besides - nothing like "getting down and dirty"!!!
Thanks for the response!

rossfingal

(Oh Boy - I've been watching the weather reports - looks like, tomorrow -
"Tunneling R Us" - Whoopie!!)

 

[jcrack_corn]

i know "she" (i'm assuming) said no money to rent. I would consider telling her to GTFO. You time needs to be assigned a value. It could potentially take you a day or two of back breaking hell to get this done, vs an hour or two sitting in a machine.

More costs than just monetary should be taken into consideration (destruction of body, destruction of a mans will, declining quality of work due to fatigue, corner cutting due to fatigue, danger of sitting in a trench).

It cost 164 bucks for 24 hours for the mini-ex at my local big box. if you make 20 bucks an hour at work, then it would seem the mini-ex for 7 hours of work is a good deal as it will at least save you that amount of time (plus you can lay your drainage and then backfill with the mini-ex saving more time).

I know you said no rentals, but i am trying to sway you because I see it just as "non-debatable" as you do!

if you do this by hand I insist on pictures and updates, use this thread as a blog. I will help cheer you on, and frankly it will inspire me if you hand tunnel through 4 feet of clay.