Grading a pad

Discussion in 'Heavy Equipment & Pavement' started by queen of spades, Mar 12, 2010.

  1. queen of spades

    queen of spades LawnSite Member
    Posts: 219

    I'm getting ready to grade a 32 x 24 pad for an outbuilding on my own property. The soil is red clay, and two weeks ago I grubbed 12 large pine stumps in the area.

    My question is what is the best way to ensure that the dirt is compacted for a concrete pad, and how (other than seat of the pants) do you check to make sure the pad is level? I was thinking of using a level and a long 2x4, to check as I went.

    I'll either use a RC-85, CL-35 or a mini-ex (NX-55). Any preference towards the mini ex vs. track loader? I'm leaning towards the NX55 since I also need to dig some french drains.

  2. Scag48

    Scag48 LawnSite Fanatic
    Posts: 6,067

    Grading a pad with a mini will be a disaster unless you're really confident in your ability to hold a grade, especially with a mini. They aren't the easiest pieces of equipment to grade with, can be done, but definately not preferred if a skid steer is an option. I recommend going the skid steer route.

    The easiest way for you to check grade is to get a laser or transit. Set it up, establish your grade and go from there. You could also set up a pair of stringlines for each axis, then run your 2X4 off the stringline elevation out into the grade and drive hubs into the ground across the pad. It's an odd way of doing it but would work if you're not able to score a transit and aren't familiar with using a pea gun.
  3. tmf lawn care

    tmf lawn care LawnSite Senior Member
    Posts: 323

    i would do the loader just take ur time with it
  4. queen of spades

    queen of spades LawnSite Member
    Posts: 219

    What steps need to be taken to compact the pad area? Is running over the dirt with machine's tracks in 6" layers enough?
  5. Junior M

    Junior M LawnSite Fanatic
    Posts: 13,552

    Personally, if I had more work to do that a trackhoe was needed for. I'd just get the trackhoe and do the whole job with it. Sure its a little harder to hold a grade with, but why rent 2 machines? Thats just more money going out..
  6. queen of spades

    queen of spades LawnSite Member
    Posts: 219

    Junior that is my thought process too. I have a small compact tractor with loader, so I can do light grading with it. Plus the NX-55 has a dozer blade for moving small amounts of dirt.. I was thinking of using the 3' dirt bucket for the excavation, then doze it as needed.

    The alternative is rent two machines as you say. I'll spend the same for a smaller mini-ex and CTL as i would the NX-55.
  7. Junior M

    Junior M LawnSite Fanatic
    Posts: 13,552

    Thats the way we do business right now..

    Except we rent a 5ton mini pretty much all the time..

    We've done plenty of jobs with a trackhoe that it woulda been nice to have a loader and trackhoe on. But the trackhoe got the job done.. I'll see if I can find a pic of that pad and swale we graded with a trackhoe cause it wasnt in the budget for a loader to come in and grade after removing the stumps..
  8. Danny Boy

    Danny Boy LawnSite Senior Member
    Posts: 255

    Do you intend to put the concrete slab directly on the clay?
    I would put four to six inches of clear crush gravel under the slab for drainage, extend it past the slab by at least 18 inches all round and level and compact it.
    CTL would be my choice for grading a pad this size:)
  9. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Posts: 4,276

    3 to 6 inch lifts will be fine. If you are going to pour a slab it is best to do a mono and dig the footers to virgin hard pan. If it is a portable building just compact well.

    The skid will be the fastest but the mini x will work .

    For level you can use anything or just rent a laser from where you get the equipment. They usually charge about 45 a day for them.

    One problem you will have is where the stumps where the soil will need to be removed and all roots gone. Usually you just window the area down to you get to clean virgin soil.
  10. flairland

    flairland LawnSite Senior Member
    Posts: 640

    I think it depends on your skill level. If it were up to me, a mini ex would be my first choice. If you have never ran one, its a tough job to learn on. Use whatever you feel most confident on, because if you're not dead on grade, you could be spending a lot of extra money on concrete... and that gets expensive quickly. Also, I'd never lay a pad down on virgin soil, I always put at least 6" of gravel down, plus compact w/ a compactor, any track machine does not have near enough psi.

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