# how to dig out basement



## AustinDB

Looking at a job where the basement depth will be increased by 2' to make the basement 'useable'. New addition will be added and access will be easy, except for the low headroom of approximately 6'-6'6". No overhead lifting-but still a bobcat may not fit. I'm sure a Dingo would, but may take a considerable amount of time to remove 2'.


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## wyoming 1

What are your plans against the exsisting walls and footers?


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## concretemasonry

When you go from 6' deep to 8' deep you are not just adding 30% to the lateral load on the wall/footing, you are adding about 80%, which can easily cause a failure or movement. As Wyoming said, you must be concerned with lateral support while digging, during construction and when it is finished.

Also, you should not dig any closer to the existing footing than the depth you are blow the existing to pour a neww footing/curb.

There is nothing worse than having a problem that causes settlement or lateral movement and cracking all through the house (VERY BIG $$$s!!!!!) the walls are holding up.

You should have someone lokk at the situation before you run off and start digging. The equipment you use is a minor problem unless you use the "bigger the better" philosophy.

Do it section by section and then wall by wall. - While you are there, interior drain tile to a sump is a "dirt cheap" investment before you pour the floor.


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## AustinDB

thanks for the concern-the existing outer block walls are coming down, new footing going in and wall to top it out. If the bottom 4 four courses of block (then sill plate) were in good condition, I would consider underpinning in thirds. But as condition of subterrain block is poor, makes the most sense to start over. I've got this part licked-still looking for feedback on the original question


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## neolitic

Look through the excavation 
and demolition fora (forums).
There was a guy here from...
Cincinnati(?) who had equipment
made for this kind of work.
Can't remember a name, but it was
probably last winter/spring-ish?


Or you could do it the way my
Grandpa did.
Get DuPont to help! :laughing:
Good luck.


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## Aggie67

Ever use a Dingo TX? Not an excavator, more of a loader. Low height. I think I have pictures of us digging out aluminum fines from a separation pond with that thing. We had a problem with the support steel for the skimmer arms being low and all over the place, and we couldn't drive an excavator into the thing. It worked pretty well for a bulk of the material. But all it did for us was push the solids into a small dumpster, which we lifted out with a Lull. The pond was about 50 feet in diameter, 9 feet deep, shaped like a salad bowl. We took out 140 yards in a few days. Customer made a nice buck recycling that.

But I'm not sure that would work for you. The stuff we moved out was the consistency of wet sand, and it was easy to push around.


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## backhoe1

I did a job real similar this summer, bobcat 742b did every bit of it, machine is only about 6' dug down to grade and backed out. we dug out a 24x32 foot add'n roughly 4' deep in one day.


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## rbsremodeling

72chevy4x4 said:


> thanks for the concern-the existing outer block walls are coming down, new footing going in and wall to top it out. If the bottom 4 four courses of block (then sill plate) were in good condition, I would consider underpinning in thirds. But as condition of subterrain block is poor, makes the most sense to start over. * I've got this part licked-still looking for feedback on the original question *



WTF? is the question. You really did not ask a question? What is it that you want to know


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## plazaman

by hand, thats how we do it when the rare opportunity comes by


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## neolitic

Don't know if it helps, 
but this is the guy I was 
thinking of.
http://www.contractortalk.com/members/crete-buster-19433/
Maybe you'll get some ideas.
By hand is what I know, 
and I know I'd like a better way. :thumbsup:


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## Crete Buster

I am creating this post in response to Neolitic's post. I would not have created it otherwise. (as not to be self promoting) I am the guy from Cincinnati he is referring to. We have electric powered mini excavators that we have used in hospitals, food processing plants, pharmacies and any place where space may be limited and/or fumes can be dangerous. Check out http://www.cretebusters.com and http://mini-equipment.com for more info and let me know if I can be of help. We specialize in confined space excavation and demolition. I'm not sure if this will work or not, but I've attempted to embed a video of one of our recent projects. http://www.youtube.com/watch?v=66Aw__tE0m4


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## neolitic

Crete Buster said:


> I am creating this post in response to Neolitic's post. .........


So.....
You have "Auto-Notify" 
if your name is mentioned? :laughing:


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## Crete Buster

:laughing: Yeah I know. I had already started my reply before I saw that you had posted my info.


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## Crete Buster

There's not much "getting out" in Cincinnati right now thanks to the weather. So I've been in front of the computer most of the day.


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## neolitic

Crete Buster said:


> There's not much getting out in Cincinnati right now thanks to the weather. So I been in front of the computer most of the day.


*Tell* me about it.


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## AustinDB

rbsremodeling said:


> WTF? is the question. You really did not ask a question? What is it that you want to know


not sure what your problem is...the title of the post was the question and elaborated up in the body If you're complaining that it didn't have a question mark, well, that's just being picky  What's next, slamming me for run on sentences or ending a sentence with a preposition 

keep it lite baby!

someone posted about the Dingo-I was hoping to get feedback about that unit. I know they have tracks-how is the traction and load capacity? 

The mini-excavator looks pretty interesting. I'm guessing it's only used on concrete floors-what is the weight? Would be worried about the speed of the unit-scoop dirt, drive dirt to opening, return for another scoop...


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## LNG24

72,

I am kind of lost too. Let me know if I am wrong.

1) You are replacing the entire foundation
2) You want to dig the basement deeper
3) you are worried about getting equipment under the house?

If I am right, you would jack up the house and rest it on cribbing. You can put it as high as you need it to fit the equipment under there. We can usually get under there with a 30,000 - 40,000lb excavator and a little hand digging. 

I have found that its usually easier to leave the existing foundation (if its in good condition and up to todays codes) and simply lift the house up to where you want it. You can add a knee wall on top of the existing foundation or block it up higher.


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## dakzaag

LNG24 said:


> 72,
> 
> 
> If I am right, you would jack up the house and rest it on cribbing. You can put it as high as you need it to fit the equipment under there. We can usually get under there with a 30,000 - 40,000lb excavator and a little hand digging.
> 
> 
> I have found that its usually easier to leave the existing foundation (if its in good condition and up to todays codes) and simply lift the house up to where you want it. You can add a knee wall on top of the existing foundation or block it up higher.


laid 6 courses of tens under one just like LNG24 described this summer, the owner had a house mover lift it.:thumbsup:

I think the OP said the foundation wasn't so good:w00t:

I would think the bobcat would work the best, Is there concrete down there or is it a crawl space?


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## LNG24

@dakzaag; Yeah, I kind of got that too, but I am not sure if he was talking the entire foundation. 


@72 Still having trouble determining the question, but if it is simply; Will a Skid Steer fit thats easy enough to figure out.

According to the Bobcat website: http://www.bobcat.com/loaders/product_lines/track/t250

T250 Track Steer is 80.9" high:whistling(close)

S205 Skid Steer is 76.3" high so either would fit. :thumbsup:

However, 2' of soil is not that much to dig by hand. That being said, you won't find me doing it:no: but you will find my guys doing it.:notworthy Of course they will be like


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## AustinDB

I'm sorry for the lack of detail guys. 

The goal is to use a machine to increase the depth of the crudely laid conrete floor by approximately 2'. Not looking for info on the outer wall dig-that can be done w/ a mini-excavator. The existing floor is broken and somewhat crumbling concrete-likely not laid on a solid base cracked throughout (for easy breaking). It sounds as if a T180 would do the job, digging the additional depth while working toward the interior.


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## MBS

72chevy4x4 said:


> I'm sorry for the lack of detail guys.
> 
> The goal is to use a machine to increase the depth of the crudely laid conrete floor by approximately 2'. Not looking for info on the outer wall dig-that can be done w/ a mini-excavator. The existing floor is broken and somewhat crumbling concrete-likely not laid on a solid base cracked throughout (for easy breaking). It sounds as if a T180 would do the job, digging the additional depth while working toward the interior.


If you're going to be digging under a house with a skidsteer, hire a pro. Putting anyone in there without thousands of hours of experience running a skidsteer under those conditions could easily result in death or serious injury. You have to know the machine you're running. By that I mean, the size, where its top, tail, and outer corners are, the precise handling attributes, power, everything must be known by the operator. The operator must know that machine intimately, because there is no room for error, not even once.

All it takes is raising the boom a few inches too high, or turning and having the tail hit the cribbing, or digging too close to the cribbing, and you have a disaster on your hands. There is virtually no room down there for a skidsteer of any size. 

A T180 is 7 foot high, 12 feet long with the bucket on it, and 6 foot wide. It needs room to maneuver under the house. When it makes a sharp turn, the wheels skid sideways, plowing up the dirt as much as 9 inches high, which then must be driven over. Will that operator instinctively know this and act accordingly? That is only one example of what an operator must know. 

Hiring a pro will get it done much faster, safer, and better, and he can tell you what it would take to dig out the basement and concrete properly. If I wasn't so far away, I'd come by and take a look for you.


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## dakzaag

Drive in back out, repeat 2000 times or so... Not exactly rocket science.

the best way to tell if the operator knows what he is doing is to listen to 
the engine RPM. anything above 2/3 throttle = different operator.

Send pics when done, sounds interesting. Saw this done 10 years ago. The guy used a farm loader tractor (no cab) with the roll bar and exhaust removed. I thought he was nuts, but he just went slow and steady and 2 days later they were pouring footings.


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## monkey

No answer to your ? but I have a story some of you might enjoy hearing.
A guy I worked with brought me over to his fathers house once(an old bricklayer-the kind of guy who could out work all the kids with a cig hanging out of his mouth). He showed me the basement. The guy had cut out the floor in a closet grabbed a shovel and 5 gl. bucket and went to work.. a steep staircase went down to a full basement with pooltable and walkout slider.I don't think a building inspector ever saw it....
I think originally it was a 2 ft. crawlspace


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## Tom M

Dick, Have you ever done one or know how it gets dug deeper? The slab is supposed to resist any inward pressure from the soil on the side wall just the the floor braces the top half of the wall. So if you dug deeper inside the basement that would require under pinning & doweling to transfer the loads to the new slab? Is that right? I thought I remembered and old episode on TOH where they dug out a crawl space to put a garage under the house. I dont remember new footings.


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## Ed the Roofer

greenfin said:


> Thanks for telling me. I ll' try to act upon your advice.


What type of contracting trade, is "Not A HomeOwner"?

Ed


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## AustinDB

did we miss somethingi Ed-where is Greenfin and why are you up at 2:30 in the morning? That sure IS dedication to CT!


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## SLSTech

72chevy4x4 said:


> did we miss somethingi Ed-where is Greenfin and why are you up at 2:30 in the morning? That sure IS dedication to CT!


First to the Mods & Nathan - Thanks for keeping the site up & clean

72 - a greenfin was probably a 12 year old with a little to much time on his hands - he had joined about 10:30 & by 1:30 he had 17 replies just like the one shown & was still going strong


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## AustinDB

I haven't stopped to think about it in more than two years, but this site is quite a bit cleaner w/ less arguing than when I joined. You're right, the mods do a great job of keeping bad traffic off the site-thanks guys!


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## Willie T

I did this same thing with a bobcat. Had to remove the basement personnel door casing and the scoop bucket to get the bobcat inside. Then I just kept some teenagers busy with a "bucket brigade" of wheelbarrows. They filled up just inside the basement door. Plan for some forced ventilation. A basement isn't designed to have a bobcat running inside it... a fair amount of fumes.


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