rock tonnage, are my calcs right?

Discussion in 'Landscape Architecture and Design' started by toxic man, Apr 13, 2005.

  1. toxic man

    toxic man LawnSite Member
    Messages: 90

    I am bidding an area which is 70 X 20. and I want to cover it in 3/4 inch rock, 3.5 inches deep.

    My calcs say 2.60 tons of rock, having to wheel barrel it 100 feet, spread by hand and rake.

    405 installed.

    Does that sound right?

  2. pjslawncare/landscap

    pjslawncare/landscap LawnSite Bronze Member
    Messages: 1,410

    What kind of rock? feild bed? 70' x 20'= 1,400 sf. should be much more than just 2.6 ton. Im figuring more like 7 to 9 tons
  3. dvmcmrhp52

    dvmcmrhp52 LawnSite Platinum Member
    from Pa.
    Messages: 4,205

    You'd be giving it away for free at $405.
    The stone calculator just came up with 20.4 tons.

    Your calculation may have missed a zero..........Rather than 2.6 tons it should maybe be 20.6 tons.
  4. toxic man

    toxic man LawnSite Member
    Messages: 90

    WOW where do you get one of those? I need one!

    20 tons that is alot of rock!

    I dont know if I wanna get into that.

    I have called areound today and got rock volume estimatesa between 4 and 32 tons, how could this be?

  5. dvmcmrhp52

    dvmcmrhp52 LawnSite Platinum Member
    from Pa.
    Messages: 4,205

    There is a link on this site.........Let me see if I can find it quick...................
  6. dvmcmrhp52

    dvmcmrhp52 LawnSite Platinum Member
    from Pa.
    Messages: 4,205

  7. yrdandgardenhandyman

    yrdandgardenhandyman LawnSite Senior Member
    from midwest
    Messages: 953

    I think it has a lot to do with the size of the stone. 1" stone takes up a lot more volume for weight than 1/2" stone because of the difference in air space.
    Type of stone makes a difference too. Marble would be much more dense than limestone.
  8. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Messages: 2,781

    OK, I'm doing the math and I like his 2 ton figure a lot better than 20 tons.
    70'x20'=1400sf at 4" (yes he said 3.5")=470cubic feet
    Even if you figured bagged rock at 2 cubic per bag and 50# bags, we are talking 250 bags to provide some fudge factor and you get 12,500# or 6.25 tons
    First reply was 7-9 tons? Sounds like good numbers to me.

    I would ask the quary or where ever the rock is coming from to convert the 17-18 cubic yards to tons for me.
  9. Popper357

    Popper357 LawnSite Member
    Messages: 217

    1400 sq ft at 3.5" is a lot of rock. River rock in my area covers 100 ft at 3" per ton, so you'd need more than 14 tons. And a bobcat.

    I'd be around $1500, maybe $1300 if good access and decent discount. That river rock costs $52/ ton retail around here.
  10. hosejockey2002

    hosejockey2002 LawnSite Bronze Member
    Messages: 1,195

    This is why they taught us to do story problems in school, fellas. Rounding things a bit, a cubic yard of material at 4 inches thick covers 80 square feet. Divide 80 into 1400 and you get 17.5 yards of material. A yard of 3/4 inch gravel around here weighs around 2700 lbs. 17.5 times 2700 is 47,250 lbs. I'd call it an even 24 tons. Always figure on the high side, you'll be better off.

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