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Discussion Starter · #1 ·
re: how long does it take to dig?

I'm going to be digging down to the foundation to replace some clay weeping tile, repair cracks, backfill, install some blueskin and a drainage mat, and create a cleanout.
I am going to hire some labour to help me out on this one.

I would have rented a backhoe, but there is not enough clearance to move it to where it needs to be.

The soil conditions have a higher concentration of clay, than silt or sand. Footing depth is only 5'.

I wanted to know approximately how much can a worker dig out in a day approximately with 2 people in a crew (including myself). I would consider getting a third person depending on the economics.
thanks
-a m
 

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Please be observant as to the the conditions of the trench wall, one of the biggest problems with doing this type of work with labor only is the spoils pile is placed too close to the edge of the excavated area. This increases the risk of cave in.

If you don't know the proper rules governing trench excavation it would be best advised that you consult someone who does know the rules and is a "Competent Person".

A few years ago in a town near me, a very similar job, and 2 men never went home.

https://www.osha.gov/dts/osta/otm/otm_v/otm_v_2.html
 

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Keeping the loose soil away from the hole is going to take longer than just digging a hole.

I dig and move the soil away for a 20X15 at the top, 20X3 at the bottom 12' deep in about 300-400 hours. Once you get down ~3', moving the dirt out takes a LOT of time.

Get a third person to wheelbarrow. Two can fill a wheel barrow about as fast as it will be moved, dumped, and brought back. Or go with two, and take turns digging so one gets a break. A low cart is even better than a wheelbarrow.
 

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What is the length of foundation wall to be exposed ?? That seems like a quite a bit of digging by hand. You can't get a mini excavator in there ?

One trick to loosen the soil so it is easier to dig is using an air compressor and a 3/4" pipe with a shut off valve. We use that when digging around utilities in tight areas.
 

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Lord help you in this area if you get up against some dry gumbo. I was helping a guy a few years ago and he was fighting for every slice with a mini-ex. If you were using a shovel, you would switch to a hammer & chisel.
 

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I'll bet you won't in middle tennessee.
Not even in lots of places. Ignoring ledge and boulders (they're everywhere) central Texas has some real crap to dig through. Sorry I missed out on middle Tennesee's crap - probably another place that's easier to put a sonotube up and fill around than dig a hole...
 

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Not even in lots of places. Ignoring ledge and boulders (they're everywhere) central Texas has some real crap to dig through. Sorry I missed out on middle Tennesee's crap - probably another place that's easier to put a sonotube up and fill around than dig a hole...
Yep, if elevation is optional.

We do a lot of blasting.:thumbup:
 

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thanks for the link. this is definitely worth reading.
Thank you, for taking the situation seriously enough to follow through and read up on the proper procedures. Please do read up on the regulations.

One of the biggest issues I see with digging up an existing foundation is that you have no way of knowing how much of the soil adjacent to the dig is virgin soil, and how much is fill, or imported material.

As stated a couple times above a mini ex will save you a lot of time and make the effort to create safe working conditions much easier.

I would consider getting a third person depending on the economics.
Economics should never enter into your thought process when doing this kind of work. You price the job to do it safely, there is no other option.
Of course we all want to "win" the project, but at what cost?
There is risk involved no matter what you do in the construction business, minimize your risk and make a fair buck is all most of us try to do.

If you find the customer's budget is not compatible with completing the job safely...move on.

Oh, Welcome to the site! :D
 

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Discussion Starter · #17 · (Edited)
thanks for all the comments!
the reason it is only 5', is because the basement has 2' clerestory windows below the joist with the grade slightly below that. If i measure the height of the soil, from the basement and taking account thickness to the slab, we are looking at only 5'-6' feet. I don't think i would attempt it if it was deeper due to the safety issue, of making it wider in a small space.

the soil in this city (toronto) is not very rocky, but there are unexpected boulders from time to time. in this type of construction they used to just backfilled the soil here after installing clay weeping tile and tar on the foundation wall, but it is probably compacted due to freeze thaw and soil hydrolics over 50 years.

Yeah, i wish i could rent an excavator, but as i said, there is not enough room to drive it where it needs to be. (fences are in the way).

If the dirt is dumped farther away as recommended, from the comments it seems as though i could do mabye 1 linear foot per hour with a two person team, and 2 linear feet with a 3 person team.

It is definitely worth thinking about giving this a pass due to the difficulty and safety.
thanks for all the tips. much appreciated.
-am
 

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Discussion Starter · #19 · (Edited)
You can always remove the fences and then reinstall when the project is completed
i wonder if it is worth the hassle.

Chain link yes, but wood? i am not sure that can be done without removing the posts from the soil It is a good idea though, definatley worth looking into.

I just read the OSHA document. Most interesting is the guidelines and drying for each type of soil and the methods for safe digging. I am thankful, that it is not near the lake, from what i was told a while ago, that soils are more silty there. Yeah for clay stability! doh for digging it.
 

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x2 what Tom said, safety should be your #1 concern. Get a small track hoe and you will get that done in no time and it will probably cost you less if you think about it, not to mention how much time you will save.

Something like this.
 

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