Recommendation for proper equipment for digging a foundation on hill

[Richard Zimmerman]

So I'm a newbie. I've done some work with a skidsteer and a mini-ex when I was redoing my backyard. Couple days with a rental unit, but I'm a newbie (I did pop my "crashed into the house with a skidsteer" cherry though...)

Anyway, the wife and I are building a Guest House. Here in Tucson that's generally slab on grade, but we live on the side of a mountain, so I'm estimating there's going to be about 300 yards of dirt that need to move around (along with a bunch of mesquite trees that need to be pulled up). There's some 3-4k pound boulders that'll need dragging/moving. Plus there's a 30' long 4' deep trench that needs to be dug for a drainage culvert. I'm actually considering just purchasing a used piece of equipment from Craigslist, drive it around for a few weeks/months, and then try to resell it. Having a heavy piece of equipment around during construction would be nice. I've got a budget of about $15k.

So, I'm wondering a few things. First, am I crazy? Next, what piece of equipment should I get? I initially thought of a small 42" bucket skid steer , (a guy here locally is selling a S630 for $12k) but I guess I'm not sure about how well a standard bucket without forks is at digging virgin dirt with lots of rocks. Would I need a mini-ex to break up the ground? Plus I'd end up having to dig the trench by hand. Not really that big a deal, but still.

Then I thought about maybe a tractor/baby backhoe. A guy I know will sell me a Kubota L48 for $11K. That would seem to be versatile, but a lot more unwieldy up on the hill as it's so much longer than a skid steer and it just looks less stable, and I don't think its bucket capacities would be as great.

Anyway, just looking for some advice. Incidentally, time is something I've got some of, so if the project takes me 2 months of weekends, that's OK.

 

[AzIron]

I do believe the foothills in Tucson are similar to north scottsdale so I will suggest for that job nothing short of 12000 lbs machine 16000 lbs would be better

You can find rock buried in that's common size is 2 foot minus or bigger a skid steer is not going to take that on very easy and a mini backhoe or mini ex wont fair a whole lot better unless you plan on like 6 months of Saturdays

Do you have retaining walls for the pad if you do and there over 3 foot tall your footings for the wall will be bigger than what a mini ex can effectively do

How deep is your cut there is a good chance you will find solid rock before you get grade then the real work starts you need hydralic hammers and machines a lot bigger than a mini or a skid steer hammer.

The material you dig up will likely have to be screened down to 6 inch minus so when you can get enough compaction to certify the pad (big rocks dont compact very well) so if you do screen then you need a screen and now haul off the rejects as well

At 15000 bucks your not going to find a machine up to the task more like 25 to 30 thousand if you want it running when you get done

If you were in fluffy flat ground dirt it would be easy but on hill it's a 2 to 3 times the work and if its granite good luck

 

[Richard Zimmerman]

Cut about 6' in one area. The rest is around 3-4'. All of that will have to be retained (essentially we end up with a walk out basement on the first floor). I had a pool dug last year about 30' from where I'm planning the guest house and there were shockingly few rocks. Shockingly because when I dig in the yard I inevitably find lots of rip-rap sized rocks so I fully expected a lot of rock, but apparently once they got below the surface all they hit was sand. I'm hoping that 30' to the north I'll hit the same geology.

Regardless of what happens, if I hit a ledge I'm done. That's for the experts. As for compaction I actually don't think I'll need to build over any fill. Gauging from my current plan and what the existing elevations tell me I think I just need to cut. The spoils will end up dumped farther down the hill but won't be built on. I might have them trucked away if I don't like how things are turning out.

My thinking here is that if I get a relatively OK deal on a piece of equipment, should I run into nasty trouble I can always just hire the job out and sell the equipment at nearly the same cost I bought it for. Maybe I'm crazy (at least that's the impression I'm getting from your message). So you think I'm just pissing away time and money trying to do this with a skidsteer or a 7800lb Kubota L48? I'd be better off buying something far more expensive (which is likely going to push me beyond my comfort range) or else just hiring the whole job out. That's unfortunate. I was really looking forward to doing some real digging...

 

[AzIron]

Not crazy

The geology here can change in 10 feet or 100

My comment above is based on my experience to make a best educated guess at a job I will never put an eyeball on

If ther is not really any rock in the ground a skid steer might do a reasonable job just slow

Your not crazy but you may not know what you dont know in the last year I have done 2 jobs like this for home owner builders and turned down 4 or 5 of them most have no clue of what the job is and what it will take and they think we are robbing them blind when they get a price especially after a portion of it is done and has to be fixed because it was not done right

Your at least asking questions to go into this somewhat open minded

 

[Jeckyl1920]

You could rent a backhoe and likely do this job in a week with a moderately skilled operator and a labor, so long as you can check grade as you go and don't make too much of a mess of it.

If everything is planned properly, and you dont run into big rocks, it could be less. It could take longer as well. Experience plays a big part in how long things like this take.

 

[Grady]

I agree with AzIron that your machine choice is too small for that job. What about renting a full size TLB for a day just to try it out and see if you feel comfortable enough with it. Running a machine on a slope presents it's own challenge and dangers.

What Jeckyl said, too.

 

[Richard Zimmerman]

Thank you all for your suggestions. They've been very helpful. I'm hesitant to rent just because my schedule doesn't really allow me the luxury of spending full days (let alone full weeks) on a project, and when you're on the clock with a $400/day machine rental you don't want to be pausing to run watch a kids soccer game. Furthermore, I've never taken on a project this large by myself before so I'm sure I'm going to run into snags here and there and want to post to this forum or else change my plans, re-shoot grades, etc. Again, it's hard to do all that when you've got an expensive rental machine sitting there. Plus if I had a piece of equipment here I could use it to move rocks, or clear brush, or lift building equipment onto the roof, or move a huge pile of A-B from the end of the driveway onto where my pad is, or backfill behind the foundation walls once they're built, etc. etc. Again, hard to do that when you've got to run to the rental center for each task.

With the idea of "a picture being worth a thousand words" I figured I'd throw over a quick album of photos of what I'm looking at. Here ya go: https://imgur.com/a/vz8izb5

 

[Grady]

I'm not sure if it was clear enough or not but I was suggesting renting a machine for a day to see if it's something you think you are comfortable with enough to buy one. After viewing your pics, I still think you need a bigger machine. I don't consider a skid steer as a machine for excavation of virgin soil - except at the beach. I know that some people will disagree. I also don't think you should use the bucket on a full size TLB for the same reason - it's too hard on the machine and it wasn't made for that. Dig with the hoe and load or move material with the bucket. Maybe sub out the major excavation and get a skid steer for the finishing touches, cleanup and landscaping? Looks like a nice place.

 

[Richard Zimmerman]

So let me see if if this makes sense. Rent the big heavy machine to do the heavy digging (with the hoe). Start with 1 day to see how I feel on it and then add days in as necessary to complete the job. Still purchase something little to move the spoils around and do general around the jobsite stuff (e.g. moving A-B, backfilling behind trench, etc. Does that make sense?

If that does make sense, would the S630 skidsteer or the small Kubota L48 tractor/backhoe be a better choice (or maybe something else). They seem to be roughly the same price ($12k).

 

[Grady]

Or buy a used TLB if you like it and it works for what you need to do. It's hard to say what is best for someone else. Small machines are nice for around buildings. I've seen small excavators do a lot of work but you have no loader and a skid steer has no hoe. If you get all the major digging and trench work done, you wouldn't need the hoe anymore. So... Your last idea sounds plausible. At least you can try it out before making a major purchase or deciding to sub it out. There is a learning curve that shouldn't be overlooked. I'd rather learn on a rented machine as they are expensive to fix as well as dangerous to operate on a slope. Have a plan before the machine arrives as to where to start, where to put the diggings, etc. It multiplies in volume when excavated [as you probably already know from your pool] so leave plenty of room.

 

[AzIron]

A skid steer wont touch that stuff with out huge amounts of time or lots of aggravation

A full size backhoe will do that job without pushing it your ground is not overly steep the trick is to keep a level spot to work and have room to shovel your material to as you chew the face build a pile after a while use the front end and haul it to were your dumping your spoils but there is no less than 2 weeks of work there for one machine

I did a pad earlier this year granted it was 16 foot cut and 4500 yards of material but I had 1 20 ton excavator and 1 14 ton excavator there for 2 months

Like grady's said that stuff has a fluff factor of no less than 1.5 maybe 1.75

As for buying or renting to get a good backhoe you will have 25000 dollars into it a decent skid steer is 12 to 14 thousand

I have never run a mini backhoe but as far as a chore machine I personally would get one of those before I get a skid steer it wont do anything fast and it's got no power but you can dig holes and carry dirt with it at half the investment of a mini ex and a skid steer to be able to do the same

Just my 2 cents

 

[ianjoub]

Beautiful work on the pool, though no constructive advice from me on your dilemma.

 

[ianjoub]

I don't consider a skid steer as a machine for excavation of virgin soil - except at the beach. I know that some people will disagree.

LOL

I don't disagree. I live in FL and the whole state, even inland is a beach (all sand). I have dug HUGE holes with my skid steer, but as you have said, I am at a beach. It is all sand. I have to buy rocks if I want them.

 

[Grady]

ianjoub, I'll give you as many rocks as you want for free - here in the granite state. ; )

Richard, for that one job, I'd just rent a backhoe. If you have a lot of land and other major projects - that's another story. One of the many benefits of renting is you get to run a new or newer machine than your budget would allow you to buy. No costly maintenance or repairs. While it's not impossible to buy, use, and resell - It doesn't always work out. You could end up losing way more money than the cost of renting. You'll make the call but try to imagine what can go wrong because it many times does esp. with limited experience - no offense. As far as buying, a smaller piece that will be useful after the initial dig seems more practical to me - from here, anyway.

 

[franklin2]

I am doing the sam

So I'm a newbie. I've done some work with a skidsteer and a mini-ex when I was redoing my backyard. Couple days with a rental unit, but I'm a newbie (I did pop my "crashed into the house with a skidsteer" cherry though...)

Anyway, the wife and I are building a Guest House. Here in Tucson that's generally slab on grade, but we live on the side of a mountain, so I'm estimating there's going to be about 300 yards of dirt that need to move around (along with a bunch of mesquite trees that need to be pulled up). There's some 3-4k pound boulders that'll need dragging/moving. Plus there's a 30' long 4' deep trench that needs to be dug for a drainage culvert. I'm actually considering just purchasing a used piece of equipment from Craigslist, drive it around for a few weeks/months, and then try to resell it. Having a heavy piece of equipment around during construction would be nice. I've got a budget of about $15k.

So, I'm wondering a few things. First, am I crazy? Next, what piece of equipment should I get? I initially thought of a small 42" bucket skid steer , (a guy here locally is selling a S630 for $12k) but I guess I'm not sure about how well a standard bucket without forks is at digging virgin dirt with lots of rocks. Would I need a mini-ex to break up the ground? Plus I'd end up having to dig the trench by hand. Not really that big a deal, but still.

Then I thought about maybe a tractor/baby backhoe. A guy I know will sell me a Kubota L48 for $11K. That would seem to be versatile, but a lot more unwieldy up on the hill as it's so much longer than a skid steer and it just looks less stable, and I don't think its bucket capacities would be as great.

Anyway, just looking for some advice. Incidentally, time is something I've got some of, so if the project takes me 2 months of weekends, that's OK.

I am in the middle of same scenario you want to do, but I spent a little less money on the equipment. Hopefully if you spend a little more, you won't have to work on it as much, but be prepared to do so. If you want to buy a piece of used equipment, and when it breaks get someone else to repair it, I would not do it, I would rent like the other guys mentioned. It's just too costly to pay someone for repairs.

I live at the bottom of a mountain, and had large amounts of water entering the basement of a house I bought. After thinking about it for awhile, I decided to buy a used backhoe and do the work myself. I bought a used Case 480C for 6500.

I knew I had some repairs going in, no brakes, some of the cylinders leaking, etc. I got the brakes going good enough to use the machine, and fixed the most obnoxious leaks. I was then able to use the machine off and on all summer, excavating around the back of the house to install a french drain and to re-grade the yard to slope away from the house.

It is nice to be able to work on it whenever time allows, but I found out some operations need to be done in a timely manner, like digging a deep trench, and then it rains and it starts caving in. So certain things you do you might need to skip your ball games and get er done before the weather or some other factor ruins it.

I have done a few minor things for neighbors also, some are not shy when they find out you have your own backhoe. I still have to dig out around one of my garages, the hill behind the back wall is pushing the back wall into the garage.

 

[ianjoub]

ianjoub, I'll give you as many rocks as you want for free - here in the granite state. ; )

If you will deliver to FL for free, I'll take every one you can get your hands on!

I lived in Manchester for a few summers. All that rock can make nice landscaping. Granite can be quite beautiful.

 

[Richard Zimmerman]

I’d do the repairs myself. I’ve got a full shop where I can pull engines if necessary. I’ve got a lathe and mill to make more intricate parts and a weld shop with lots of scrap for heavier repairs. I’ve actually considered purchasing something broken and fixing it up rather than something running tip top, but I’ve never worked on or owned a piece of equipment like this so I wouldn’t really be able to look and something and guess how much it would cost to bring up to working status. Plus I’ve been told that these hydraulic components can get pretty damn pricy.

 

[Grady]

You sound much better equipped to handle owning a piece of used equipment than most but it can still be very time consuming and expensive. That goes back to the idea about using and reselling. If you have a machine that you can use enough to justify that kind of investment - not just digging one hole - it makes more sense to me. - and everything is expensive, not just the hydraulics but you're right, the price of most hydraulics - except seals and o-rings will really get your attention. Most equipment doesn't allow for just pulling the engine or dropping the transmission or differential. It usually involves splitting the machine and though do-able is way more involved. Again, your time, your money, your call.

 

[Buckethead]

For excavating foundations or grading for floor slabs, I recommend hiring an excavating contractor. Those are not jobs for a beginner, as cutting too low will have to be filled in with concrete, and concrete is expensive. I don't know how steep the slopes are, but slopes are not really a good place for a green hand to break in. Digging the trench would be an easier task for a beginner, though.

 

[Dave Neubert]

I have been in the equipment repair business for close to 40 years and can't tell you how many times I have people cry because they bought cheep piece of equipment to do a job and then plan on reselling it after they are done. but in the mean time had a major failure the cost as much as they paid for the machine. So they can't afford to fix it and can only sell it for junk. So if you are going to do this buy a good machine 30,000- 50,000 dollar range and hope you don't break it. My advise is to hire it done and let them worry about it.