# Using reciprocating saw to cut compacted dirt



## cchean (Oct 5, 2017)

I will have to dig 4 18" x 18" x 12" deep square holes in my crawlspace to build a small foundation for some steel shores. Since my CS is only 24" and the soil is somewhat compacted, would you think that using a reciprocating saw to cut at least the border of the hole will make it easier? Am I saying something stupid here? I know it will be messy.


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## MTN REMODEL LLC (Sep 11, 2010)

I don't know what your CS is....\

I'd never thought of a recip to do that.....but I have a spade bit for my bulldog hammer drill that I use all the time in digging.


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## SeniorSitizen (Sep 10, 2012)

I've never tried it but i've read of using a chain saw for trenching. Electric in a crawl space.



I don't see much advantage of just cutting a kerf unless it will allow chunks to be broken out.


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## ZZZZZ (Oct 1, 2014)

cchean said:


> I will have to dig 4 18" x 18" x 12" deep square holes in my crawlspace to build a small foundation for some steel shores. Since my CS is only 24" and the soil is somewhat compacted, would you think that using a reciprocating saw to cut at least the border of the hole will make it easier? Am I saying something stupid here? I know it will be messy.


Just don't use your best fine-toothed blade. :biggrin2:
.
.


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## Bud9051 (Nov 11, 2015)

I recently posted on another thread about using a reciprocating saw for stump removal. It cuts right through the soil and then gets the roots. My blade was a 3 TPI heavy duty. Shouldn't be a lot of mess as long as it isn't wet.

Bud


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## Nealtw (Jun 22, 2017)

What ever works is the right tool to use.


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## cchean (Oct 5, 2017)

SeniorSitizen said:


> I've never tried it but i've read of using a chain saw for trenching. Electric in a crawl space.
> 
> I don't see much advantage of just cutting a kerf unless it will allow chunks to be broken out.


I have a small electric chainsaw that I could use as well, just concerned that it might also throw a lot of dirt as it cuts through.


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## cchean (Oct 5, 2017)

MTN REMODEL LLC said:


> I don't know what your CS is....\
> 
> I'd never thought of a recip to do that.....but I have a spade bit for my bulldog hammer drill that I use all the time in digging.


How wide is that spade bit? You use as if you were drilling or hammering?


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## XSleeper (Sep 23, 2007)

For digging in hard compacted dirt, a rotary hammer set to chisel, and an sds clay spade would be far better than using a sawzall to try and cut dirt.


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## cchean (Oct 5, 2017)

XSleeper said:


> For digging in hard compacted dirt, a rotary hammer set to chisel, and an sds clay spade would be far better than using a sawzall to try and cut dirt.


Thanks! How deep can a clay spade go?


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## XSleeper (Sep 23, 2007)

Depends on the one you use, but most are 16" long. That and the drill itself would easily dig a hole 18" deep.


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## joecaption (Nov 30, 2011)

Trying to use a chain saw will destroy the blade and bar in seconds, even cutting to close to the ground when cutting a tree down will destroy it.
If you did use a carbide tipped pruning blade to cut out the outside shape, then what, your still stuck with a hole full of hard packed dirt.
A clay bit would work sort of work, but your going to have to come in at an angle and make a trench because there's no room for the bit and the hammer drill.
Just the bit would be at least 17" long.
Who says it needs to be 12" deep?


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## Bondo (Dec 8, 2007)

> holes in my crawlspace to build a small foundation for some steel shores.


Ayuh,....... Get some of These, 'n ya only gotta level an 18" circle,.....


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## MTN REMODEL LLC (Sep 11, 2010)

cchean said:


> How wide is that spade bit? You use as if you were drilling or hammering?





XSleeper said:


> For digging in hard compacted dirt, a rotary hammer set to chisel, and an sds clay spade would be far better than using a sawzall to try and cut dirt.





cchean said:


> Thanks! How deep can a clay spade go?


Oh...You just use it on hammer.....keep "shaving" the hole out....I have several chizels....w'o measureing maybe 2-4-6".

As to deep....a sds Bosch bulldog is not a wide tool, My chizels are not long per se....as you can use the tool as deep as you can reach. *I guess I've gone 48" deep.....using it to shave/cleanup trench forms.

I would guess you can buy longer chizels if you need them.

Works great in clay and decomposed granite. Lot easier than a shovel or pick


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## Missouri Bound (Apr 9, 2011)

cchean said:


> Am I saying something stupid here? I know it will be messy.


No, you are being creative.
A chain saw will be a bit unwieldily in that narrow crawl space.
I would find a very rough blade, maybe a tree trimming blade for the job and pick up one of those old army shovels that are short and fold into a pick or a shovel.
No reason to ruin a chain saw and blade there and the reciprocal saw will handle it fine. 
Yes, there are other tools that would make the job easier and faster.
But with limited space you may find the reciprocal saw the handiest.
Once you cut the soil it should pry up without too much trouble.


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## huesmann (Aug 18, 2011)

You will quickly dull any sawzall or chainsaw blade by cutting soil, unless it's all organic topsoil. Soil is just tiny pieces of...rock.


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## HotRodx10 (Aug 24, 2017)

huesmann said:


> You will quickly dull any sawzall or chainsaw blade by cutting soil, unless it's all organic topsoil. Soil is just tiny pieces of...rock.


The chainsaw blade will dull very quickly, and dirt will hold the heat that's generated. I'm not sure how long it will continue to work, but you'll be throwing away the chain. Unless you cut a little and let it cool, you'll be replacing the bar, too.

I think a long, very coarse recip saw blade may still be the best idea, at least to cut around the perimeter. A wide scraper blade for the recip saw or demolition hammer to chip the soil out may help quite a bit, too.


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## DexterII (Jul 14, 2010)

If it turned into more than I could handle with a spade I would grab an ax or spud bar. Might be a little slower going, but could have it done by the time I messed around chasing anything else. If it's really that bad I'd go with a Bosch Bulldog and a spade bit. If you don't have and don't need one, head to your nearest HD or other tool rental. But I'd take that over a reciprocating saw. A reciprocating saw with a pruning blade would probably help, but it's not going to be in the same league as a spade bit, and it has a longer throw so if you happened to snag a root or any other unexpected object it could be a little hard on the body.


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## Missouri Bound (Apr 9, 2011)

Remember that the OP only has 24" to work in.
Swinging a pick just isn't going to happen.
A reciprocal saw and a short handled garden tool may be the best way to go.


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## ratherbefishing (Jan 13, 2011)

I'd try it. Recip blades are cheap. Chain saw bars and chains aren't.
It might even be worth picking up a scraper blade or two to break up the dirt.


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## ratherbefishing (Jan 13, 2011)

Bondo said:


> Ayuh,....... Get some of These, 'n ya only gotta level an 18" circle,.....


Hauling a few of those into a 24" crawl space looks like a good job for someone else.


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## HotRodx10 (Aug 24, 2017)

ratherbefishing said:


> Hauling a few of those into a 24" crawl space looks like a good job for someone else.


Yeah, I was thinking the same thing. However, 4 of the 4x8x16 concrete blocks might be more manageable to build a pier about that size.


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## Bondo (Dec 8, 2007)

ratherbefishing said:


> Hauling a few of those into a 24" crawl space looks like a good job for someone else.


Ayuh,..... They're round,...... ya roll 'em,......

Many precast places have the same thing, in 18" diameter,......


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## ratherbefishing (Jan 13, 2011)

Bondo said:


> Ayuh,..... They're round,...... ya roll 'em,......
> ,......


Good point. I wasn't thinking as smart as I shoulda. Thanks for reminding me.


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## Missouri Bound (Apr 9, 2011)

Bondo said:


> Ayuh,..... They're round,...... ya roll 'em,......
> 
> Many precast places have the same thing, in 18" diameter,......


But they weigh over 100#.
Just try rolling one of those while laying on your belly.


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## huesmann (Aug 18, 2011)

Here's an idea for "cutting" soil: how about a pressure washer? Messy, but might that work?


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## 3onthetree (Dec 7, 2018)

I'd back up a step. From your other thread, you're putting in Ellis screw shoring to lift up your sagging joists. These are overkill at $200-$500 a pop, and are better suited as _shoring_ a structure vs _lifting_ a few joists. You probably don't need to dig down and pour footings for a temporary jack at all. Use cribbing and bottle jack(s).


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## Bondo (Dec 8, 2007)

Missouri Bound said:


> But they weigh over 100#.
> Just try rolling one of those while laying on your belly.


Ayuh,....... Been there,..... Done that,..... Ruined my t-shirt,.....

16 of 'em,......


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## HotRodx10 (Aug 24, 2017)

Bondo said:


> Ayuh,....... Been there,..... Done that,..... Ruined my t-shirt,.....
> 
> 16 of 'em,......


16 blocks or 16 t-shirts?:wink:


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## Bondo (Dec 8, 2007)

HotRodx10 said:


> 16 blocks or 16 t-shirts?:wink:


Ayuh,...... Blocks,.......

I noticed that after I posted,........


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## ron45 (Feb 25, 2014)

This is a proven tool.


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## gthomson (Nov 13, 2016)

I wouldn't use a sawzall - I tried cutting some major offshots of a stump that were still in the ground with one - maybe 4" diameter. It was doing fine with the roots, but any time it hit a rock on the other side, the sawzall would kick back at me, and another blade bit the dust.
It might work, but it wouldn't be my first pick for trying to dig a hole in dirt.

I think I'd try a garden auger drill bit, possibly on a hammer drill if available.


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## Highlander86 (Aug 14, 2017)

For the tight confines of a crawl space, an old hatchet or a prospector's hammer should work well. Just wear safety glasses and hand protection. When I was cutting out tree roots from a tree that was removed, I did use a reciprocating saw and a heavy kerf Diablo blade with 3 teeth per inch. It was designed for pruning but I used it to cut roots after reading many reviews on Amazon. Freud DS0903CP Diablo 9" Carbide Pruning Reciprocating Blade. Work Safe!


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## A Squared (Dec 19, 2005)

Maybe something like this for the recip saw? 

https://www.tiletools.com/product/hammerhead-super-scraper-reciprocating-saws/

That would be more like a rotary hammer with a chisel bit than "sawing" the soil with a saw blade. 
.


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## ratherbefishing (Jan 13, 2011)

A Squared said:


> Maybe something like this for the recip saw?
> 
> https://www.tiletools.com/product/hammerhead-super-scraper-reciprocating-saws/
> .


Oh Yeah! That's what I'm talking about. Whose gonna post that one in here:
https://www.diychatroom.com/f29/tool-you-want-most-687555/

And I don't even need it (yet.)


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## carpdad (Oct 11, 2010)

A sawsall is expensive enough so I woudn't push the tool too much. It uses gears inside to move the blade as such and those gears have limits.


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## Katya (Dec 11, 2020)

cchean said:


> I will have to dig 4 18" x 18" x 12" deep square holes in my crawlspace to build a small foundation for some steel shores. Since my CS is only 24" and the soil is somewhat compacted, would you think that using a reciprocating saw to cut at least the border of the hole will make it easier? Am I saying something stupid here? I know it will be messy.


How did it work for you? I want to carve out space for a retaining wall. I've done the major digging, now I just want it flat and level. Soil has very few rocks and a couple of roots. It looks as if some of the pricier blades would work for this. How did it go for you? Thanks.


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## Badgerstate (Oct 19, 2020)

It will work, its just going to destroy a blade quickly, especially if you have sandy soil. Earlier this year, my wife and I bought a house and it had all kinds of old stumps and tree roots in the yard.
In the front, I had quite a few roots growing up out of the ground from trees that wont be removed until next year and they posed a danger to my lawn mower, so I cut them out with the sawzall. I just pointed the blade into the ground and cut out the parts that were sticking up too high. It worked but I had some Diablo and Makita blades and it chewed them up. The Milwaukee blades that I bought after that seemed to last a bit longer but it still destroys any blade.
A previous poster mentioned maybe using an electric chainsaw. I personally wouldnt use a chainsaw because cutting through dirt really destroys a chain and replacing a sawzall blade is much cheaper and easier than replacing/resharpening a chain.


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## jeffnc (Apr 1, 2011)

Chainsaw is a non-starter. Pressure washer - lol, a Three Stooges episode. I recipro saw will work - it's not the blade I'd be worried about as they aren't that expensive. I'd be worried about hitting a rock with the tip down and hammering that saw. That can be rough. A scraper blade on the saw will probably work better, but you have the same "jamming" issue if you hit something hard. The demo hammer with the clay blade is a good bet. So is using a good old fashioned hammer and cold chisel.


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