anyone try to dig a basement under House?

[rockinmywaypa]

Did it here back when I was younger and more ambitious. I too had a low cellar and wanted to jack the house up. Got it up about a foot off the walls and then started getting nervous.We poured cement caps on top of walls and then sloped down from about 25 ft away into the basement. I ended up using my 65 hp loader tractor[2130 jd] to scoop out another ft and a half. Had to have a long chain hooked to another tracter to pull me up the slope when backing out due to weight on loader. Made for a good father/son day of teamwork. There's more to this story about rain washing out walls before new buttresses were poured but long story short it can be done and I don't ever want to have to do it again.

 

[scout180]

My Dad dug a basement under our old farm house in 1949. He had a tractor w/loader dig a ramp outside the wall, then used shovel and slip scoop pulled up the ramp with the Farmall M. He first put a steel beam under the house frame sill. After digging, he poured a solid concrete wall - still sound today but has always leaked after heavy rain. Be sure to use new state-of-the art sealants on your wall.

Like others, I'd hire it done today! /forums/images/graemlins/crazy.gif

 

[ScottAR]

There's a thread around here with Hoeman's account of his basement job. He has/had a large JD backhoe and a goodly sized JD skidsteer for the heavy dirt moving. As I recall, he had some housemover folks raise the house off the old foundation on I beams, dug around the outside with the backhoe and spent 8-9hrs under the house with the skidsteer.

Big Job.

What ever happened to Hoeman anyway?

 

[ronjhall]

Here is a thread with pictures.
Digging out the basement

 

[MossRoad]

PowerTrom425 over on the Power Trac board is doing that right now. I believe he excavated under his house with his PT425, jacked it up 4 feet and layed a foundation. You may want to contact him for details.

 

[em14]

I had a conversation with a contractor in Northern Virginia 4 or 5 years ago who does this often. The process he uses sounds good. He jacks the house up to get it off the existing foundation and then using skid steer he digs the basement, installs the footing, the foundation wall, the basement floor and then lowers the house on to the new foundation wall. Now while this is basically simple there are many things to be concerned about in addition to supporting the house.
Leo

 

[Dutch445]

I did such a thing with a Skid Steer 3 years ago. The house was a small ranch, on a lake, with quite a grade, so the foundation was laid accordingly. Uphill foundation was about 7 course of block, downhill side was about 12 or so to the footer. The gable ends of the foundation were stepped in a couple places. My project was to go in the gable end, and set grade for 7'-6" cellar under half the house. That grade would also be the grade for the new addition which was added afterwards. It made for a nice walkout lower level, and under the existing house was converted into laundry, bathroom, storage. The uphill half of the basement I didn't excavate fully, due to the footer not being that deep. I put a 30" high cement retaining wall to hold back the earth as it sloped up to that higher wall and covered it with thick plastic vapor barrier. Then put in a nice cement floor in the excavated part of the celler. When the addition went up, the opening I had made to get in with the skid steer became a doorway into the laundry area, framed with 2x6 and a header.
There were anxious moments, as the old supports under the house were just sitting on big rocks, no real piers. When I laid the floor I put in 3 piers for the now long supports that I buried in a wall.
The skid steer worked great, and took all of the fill to the top of the lot to create a driveway/parking area.
I can't imagine doing it with a small tractor, my timeframe wouldn't have allowed me to, but i'm sure with enough time it could be done.. although I think a tractor with fel is a lot longer than a skid steer.
/forums/images/graemlins/cool.gif

 

[jim_wilson]

It has been done before - there are contractors that do complete basement replacements as well as adding foundations in where none existed before. For some good information on how you might be able to do this check out Journal of Light Construction Online . There are tons of articles in there about all sorts of construction topics. I found one article that I will try to attach - search thru their articles - I know there are at least 2 or 3 more that deal with foundation replacement or installation.

Sorry file will not attach - go to the website and search for Foundation Replacement and Retrofitting Basements and you will find some articles.

 

[PILOON]

Brings back memories!

About 12 yrs ago a buddy got a quote of $32,000 to raise dig/blast as necessary and pour a foundation.
House was about 24x40.
Brave me said "Let me do it at a guaranteed not to excede $30,000. price.
Being a good buddy I got the contract (on a handshake).
We raised the house about 9ft to allow equipment in.
I used a local sub that did that sort of thing.
Then came the blasters, Oh, I forgot to mention that the house was 3/4 on solid bedrock!
They drilled and blasted for about 2 1/2 days and we remouved all the rock with a shovel and filled in the low spots on his lot with it.
The powershovel was also needed to move the blasting matts.
Some places they drilled down 9 ft.
Then we poured footings, 8" walls and the floor.
Rebar was installed in appropriate locations (over windows doorways etc). Also used foam boards where I knew there would be inadaquate backfill.
Total of about 2 1/2 wks later the house was sitting on the new foundation and there even was new sod laid over the rubble field.
The project cost him approx $24,000. and I made very decent $$$ for my time and efforts in co-ordinating the job.

Only problems was the city that decided that we should have a 'certificate of localization' halfway into the project.
They also decided that he had an illegal view on one side in that there was an existing window closer than 6ft from that property line.
That required a notary to draw up deeds signed by the neighbor accepting that 'illegal view'.
Her house was, in effect, set back from his by some 500 ft.
Go figure.
And, oh yes, the only problems were a few 'shrinkage cracks in the concrete floor.

From my experience, a must is french drains below the footing levels if you want a dry basement.
To do that one must almost remouve the old foundations as you cant dig lower on the inside as well as the outside without a disaster.

Raising is not hard at all.
Just a lot of 6 x 6 or 8 x 8 3-4' stock to build up cribs and one good hydraulic jack.(more is better) as you essentially only raise one corner at a time by a mere inch or so.

This way you can get equipment in to do the dirty work and you end up with a far surerior result.
It actually only took a day to raise that house to 16" higher than the projected finished foundation
In our case we rented 2 (12 x 12 30') BC fir timbers so that our cribs were on the outside of the foundation.

 

[kuby]

Anyone know what the weight of a 1000 sq feet single level would be?