# Build a garage over existing basement hole



## bystry (Jan 14, 2011)

We took old home and its basement out.
The garage of the new home will have to go above where old basement was. So the hole needs to be backfilled.
Any ideas on the best and most economical way of handling it?
Gravel?
Clean Fill?
Precast top with steam walls?
Other?
Thank you


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## rino1494 (Jan 31, 2006)

Replace with clean fill and compact. Best way but not the cheapest, is to use modified stone base and compact.


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## tcleve4911 (Mar 26, 2006)

Why don't you keep the basement to the garage?
Garages are built with basements all the time.
That's free storage space. 
Put your dirt and fill money into the materials required to support a poured floor.
If you do it right, you could do your own oil changes from underneath like a Prompto or Oil n Go

Just an idea.........:shifty:


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## Williams Ex Co (Dec 25, 2007)

What tcleve said....


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## griz (Nov 26, 2009)

tcleve4911 said:


> Why don't you keep the basement to the garage?
> Garages are built with basements all the time.
> That's free storage space.
> Put your dirt and fill money into the materials required to support a poured floor.
> ...


That tcleve seems like a pretty fart smeller.:thumbsup::laughing:


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## cleveman (Dec 28, 2007)

I'd like to finalize the motion that t-cleve is a "genius, a wizard, a very clever man" (the Barber of Seville).


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## cleveman (Dec 28, 2007)

Furtermore, Frank, that barn design where you had a walk-out on both ends and a ramp going up and down on the other ends was a good design. Maybe this was used to dump silage in the basement, I don't know.


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## Tom Struble (Mar 2, 2007)

cleveman said:


> I'd like to finalize the motion that t-cleve is a "genius, a wizard, a very clever man" (the Barber of Seville).


 
i second your final...and you can put your name in too:drink:


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## bystry (Jan 14, 2011)

tcleve4911 said:


> Why don't you keep the basement to the garage?
> Garages are built with basements all the time.
> That's free storage space.
> Put your dirt and fill money into the materials required to support a poured floor.
> ...


New home footprint is different from the old home. The garage is over the basement but doesn't completly line up. Also existing home was 110 years old. So I have a hole under a big part of new garage and some driveway.


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## ElIngeniero (Feb 7, 2008)

Is there a nearby concrete plant? You may want to call and see if they need a place to dump their excess. If you're in no hurry with it, you may get a hole full of concrete for nothing. It's a long shot--but I've done it before:jester:.


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## oldfrt (Oct 10, 2007)

bystry said:


> New home footprint is different from the old home. *The garage is over the basement but doesn't completly line up. *Also existing home was 110 years old. So I have a hole under a big part of new garage and some driveway.


First off,
What part of the country are you in?
Do you need full frost walls?

You may have been able to use some of the old foundation
rubble to back fill that area once the foundation is set.
Cheap fill and already on sight.
Just have to be careful and fill in the voids with
some clean fill that would pack tightly by flooding 
the area with water and compaction.

I filled my garage with a lot of rocks dug up on site,
layered with clean gravel and let the rain compact it
till the house was built.
Once I had the house up,I set up a gutter system to
keep adding water,found the low spots,brought in more
fill and compacted.Saved a few $'s and had to get rid of
all these New England rocks somewhere.


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## bystry (Jan 14, 2011)

*thanks.*

it is very clever


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## jmacd (Jul 14, 2009)

OLdfrt, very smart. What compacts fill better than water. I do think nothing.:thumbup:


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## dayexco (Mar 4, 2006)

water is fine as long as it migrates away soon enough to firm the soil up by the time you need to build on it...and that your water doesn't wash away your clay fines from any aggregate that may be in the fill, into "pockets" and leave you with a permanent soft spot.


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## Upchuck (Apr 7, 2009)

In the old days we would backfill garages with clean fill but wouldn't compact. The client would then flood garage with water. We would then bring load of gravel & jumping jack grade for concrete guy.

The main builder we worked for didn't like this method. Mainly due to other subs complaining about flooded garage. I explained that I would have to charge more money because compacting in lifts was more time consuming. He agreed & we do this for all our clients now. 

That same builder told me that he read that flooding garage for compaction wasn't good because it still left voids in the soil. Does anyone know of any drawbacks for using water for compaction? Besides finding a electrician buried up to his knees in garage because he jumped in w/o looking.


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## Moxley-Kidwell (Jan 28, 2011)

Maybe its just me, but I wouldn't want to pour conc. over something that was full of soup. I'm sure you guys have forgotten more than I know, but I like my subgrade as tight as possible.

You could also try a local quarry, ours has a huge amount of dirty road base (GAB) that they sell cheap and it would still be pretty easy to work with and compact like a champ.


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## cexcavation (Apr 17, 2008)

Do it right the first time and you will save the money over time vs. up front. We would never get away with simple "fill" for backfilling anything structural. Everything would be proctored rock of some sort and brought up in lifts. Nuked every 6-7'. If it doesn't pass, dig it out and start over. Water is definately good, but not too much. You want enough to allow the fines to "float" and bind up. Vibrate it and go for it.


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## tcleve4911 (Mar 26, 2006)

Now THAT picture should get a "you know you're a ******* " award....:laughing:


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## JDavis21835 (Feb 27, 2009)

Upchuck said:


> That same builder told me that he read that flooding garage for compaction wasn't good because it still left voids in the soil. Does anyone know of any drawbacks for using water for compaction? Besides finding a electrician buried up to his knees in garage because he jumped in w/o looking.


Backfilled many trenches with sand, and then flooded them to compact the sand. Never had any problems with them. When I do parking lots with sand sub base, I throw as much water at the sand as possible. Last parking lot I did, I would spread the sand, and then pulling a small water wagon with our roller I would compact and water the sand at the same time. Once the area was wet, I would lose the water wagon and pack it once more. My numbers were all above the 95% compaction, with most being up around 98-99% and my moisture content was 11-12%

They key is having somewhere for the water to go. If it gets trapped, then you will have soup. Most of our parking lots have underdrains. Most of the time on trench lines the water will be picked up by the native ground around it. In the garage, as long as there are footing drains, it would be fine by me, but im not the big bad builder either.


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## Redneckpete (Feb 22, 2008)

Water works great to compact sand. Think about a beach. You want to walk along the water's edge because that's the only place the sand is compacted.

Pete


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