I have a client who wants to demo their slab in their basement and dig 6″-12″ down to gain more head room. The house is 100+ years old with a stone foundation that looks like it is sitting on dirt at the same level as the slab.
We are going to do some exploratory digging Monday and then have an engineer come out to look at it. Does anyone have any experience with this? I am sure I have let some important information out, but any info would be great.
Hopefully I can post some pictures Monday night.
Thanks again
Replies
You are probably right and the floor is the only thing keeping the dirt in place under the walls.
An engineer will probably come up with some crazy solution involving keeping the old foundation, but from our experience it's better to just replace the basement walls and be done with it.
Even to have a dirt retaining wall set inside the walls is expensive to do well.
We've had a potential client ask us to bid on a hair-brained idea involving something like 12 seperate pours and bolting the old foundation to a new poured wall just inside. We said you won't gain anything and passed on the job. He went ahead, and sure enough, with the material costs of a new foundation, he went from 6'6" headroom to 7'. The engineer screwed up the elevations and the contractor built it as designed. An expensive 6" gain.
Best of luck.
Beer was created so carpenters wouldn't rule the world.
Yes, more than once.
They need a budget for a whole new foundation.
You will also need to know where the water table lies
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Good 'over the winter' DIY job but dont see how anybody could do it well and safely and make anything unless you know you will have a few spare hours a week for awhile and drive right near the place often.
DIY I'd dig out 3 ft at a time around the foundation, pour a 1 ft wide shelf wall, do the next 3 ft 2 weeks later. After all the shelf walls in (eats up a foot around the perimeter, but one can build shelve over the step) then the floor is dug out and new floor poured.
Don't you have to pin them together?
Years ago, I was rehabbing houses in a neighborhood built in the late 1800's -- pretty much all the homes had either dirt basements or shallow basements with a rat slab. It was pretty standard procedure for folks to dig out the basement at a downward 45 degree angle from the base of the foundation, with a trench at the bottom, and then pour a concrete "retaining wall" inside the basement based in the trench and going to a height above the bottom of the old foundation. A new slab was then poured. This wound up creating a concrete "bench" around the basement, sometimes 18"-24" wide, but it seemed to get the job done.
Mike Hennessy
Pittsburgh, PA
That is what I was picturing in my mind. When I was looking in the IRC, the only thing I could find was placing a footing on a grade and it had the 45 degree angle solution.
The engineer agreed, if we go 12" down we have to dig 12" out from the wall. He also said we can pour a curb to keep the dirt back. But we are still waiting on the drawings from him so we have started digging away from the wall while we wait on the specs.
Nice to hear an engineer gave the concept the OK.
Mike HennessyPittsburgh, PA
raise the house..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Unless he has a chimney...
keep adding on to the chiney as the house elevates...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
and move the firebox as well?
now ya didn't say any thing about a fire box....
but of course...
move that too....
raise the house as a unit....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Easy to raise a chimney right along with the house
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
i did this alone... in a then 100plus year old cotton row warehouse when i was 19... 100ft long and 20 ft wide... went from 4- 6 ft dug to an even 8ft 9" then placed the concrete...
the walls were brick that got wider as i went down... building was about 23' wide inside on the 1st floor... i never got to the "bottom of the bricks" dug it by hand... with a troy built tiller break'n it up... me fill'n 5gal buckets (20 at a time) place'n them uner a hole in the floor.. and me on the first floor swing'n a rope with a hook to grab the handle... then pull'n em up dump'n dirt in cart... then dump'n cart on the sidewalk... guys work'n on the street at the time took most of the dirt away for me... if they weren't there i'd dump dirt in a trailer then haul it away... much better than going to the gym everyday...
i get tired just think'n about have'n done it...
p
We did the same thing "created a concrete "bench" around the basement, 8" wide, 36" high" on an old 1835 stone farm house 40 years ago and it has not move a speck. In hind sight, we should have had a deeper gravel base with a french drain to day light. We have to run sump during rainy springs and do not like to. Belive we could get away from it if we had the tile and a down hill escape route. We may still dig down from the out side and horizontally drill inside to the sump location - we may be able to minimize the pumping -- best of luck -- D
Solid Chat GPT copy pasta.