Estimating yards of dirt needed

Discussion in 'Starting a Lawn Care Business' started by dswinnerjr, Feb 4, 2007.

  1. dswinnerjr

    dswinnerjr LawnSite Member
    Posts: 29

    I have gotten myself in a delima, so I need some help.

    A project I am gonna start this week for a customer involves bringing in some select fill 60/40 mix of clay and sand to raise up his parking area, so that it is not a mud hole.

    The area to be raised is probably 30x40 and is about 3-4" maybe 5" below the level of the yard and he wants it about 2" inches above the level of the existing yard so that the rain will not run over the top and wash it away.

    So I order 12yds of this to be delivered Wednesday but am wondering weither that will not be enough.

    Any thoughts or advice
     
  2. freddyc

    freddyc LawnSite Senior Member
    Posts: 578

    to raise that area 6" you need approximately 22 yards of material. If you're 4-5 inches below grade and he wants it 2" above, then the 22 is close. In an area like that, you would need to add a fudge factor for uneven application, settling...etc. The are--- 30 x 40 x 6" is 600 cubic ft divided by 27 to get the 22 yards.

    I would be ordering at least 28 yards myself, or more, if you think you're already 5" below grade..

    In addition, if he's parking in there, putting a good base of gravel down might be in you favor instead of the mix you quoted. Just my $0.02. If the area is wet, he might be sinking like a stone.
     
  3. Tn Lawn Man

    Tn Lawn Man LawnSite Senior Member
    Posts: 479

    freddyc is correct. But, he forgot to write in one part of the equation so that you can repeat his numbers.

    30x40= 1200 sq ft

    1200x6= 7200 cu ft ( 6 is the number of inches deep you want it )

    7200/12= 600

    600/27= 22 cu yds
     
  4. freddyc

    freddyc LawnSite Senior Member
    Posts: 578

    yes Tnlawnman you are right...I didn't extrapolate the rest of the equation....


    I do it a little different than you though..

    30 x 40= 1200 square ft.

    1200 square ft x 0.5 = 600 cubic ft (the 0.5 references 1/2 ft deep -- 6/12)

    600 / 27 is the final cubic yard number of ~ 22.


    For a 6" depth the two calculations come out the same. I believe there will be a difference for other depths--say 4" deep.

    I think we would be 1 1/2 yds different on a 4" depth using the 2 calculation methods.

    the way you calculated it:

    30 x 40=1200
    1200*4=4800
    4800/12=400
    400/27=14.81 yards

    in comparison:

    30 x 40=1200
    1200*0.3=360
    360/27=13.33 yds.

    I believe the difference is converting the depth to a ft number vs doing it in the second part of the equation which adds a certain amount of error due to unequal units.
     
  5. dswinnerjr

    dswinnerjr LawnSite Member
    Posts: 29

    I really appreciate ya'lls help. The dirt guy I spoke to said that I did not need any gravel but to just add the same material that the ground is mostly composed of and if needed add some lime to areas of concern.

    After this area is to be raised, the customer wants crushed concrete added for a harder base.
     

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