# rock tonnage, are my calcs right?

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

1. ### toxic manLawnSite Memberfrom Ontario CaliforniaMessages: 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?

Lou

2. ### pjslawncare/landscapLawnSite Bronze Memberfrom Southern IndianaMessages: 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. ### dvmcmrhp52LawnSite Platinum Memberfrom Pa.Messages: 4,205

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 manLawnSite Memberfrom Ontario CaliforniaMessages: 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?

Lou

5. ### dvmcmrhp52LawnSite Platinum Memberfrom Pa.Messages: 4,205

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

7. ### yrdandgardenhandymanLawnSite Senior Memberfrom midwestMessages: 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. ### bicmudpuppyLawnSite Silver Memberfrom Aztec, NMMessages: 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. ### Popper357LawnSite Memberfrom Kansas City MOMessages: 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. ### hosejockey2002LawnSite Bronze Memberfrom Auburn, WAMessages: 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.