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View Full Version : rock tonnage, are my calcs right?


toxic man
04-13-2005, 11:15 PM
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

pjslawncare/landscap
04-13-2005, 11:39 PM
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

dvmcmrhp52
04-13-2005, 11:51 PM
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.

toxic man
04-14-2005, 12:31 AM
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

dvmcmrhp52
04-14-2005, 12:34 AM
There is a link on this site.........Let me see if I can find it quick...................

dvmcmrhp52
04-14-2005, 12:39 AM
www.atstecks.com/stone.htm



This is the link I have right now........It's a quick reference but it gives you an idea.........

yrdandgardenhandyman
04-14-2005, 01:19 AM
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


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.

bicmudpuppy
04-14-2005, 02:21 AM
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.

Popper357
04-14-2005, 12:36 PM
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.

hosejockey2002
04-14-2005, 04:47 PM
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.

DKinWA
04-14-2005, 08:53 PM
I actually liked math in school. Calculate how many cubic feet, convert to yards and then to tons.

20 x 70 x 0.29 (3.5 inches divided by 12 inches) = 406 cubic feet. Divide 406 / 27 (cubic feet per yard) = 15 cubic yards. Then multiply 15 x 1.5 tons (approximately 1.5 tons per yard) = 22.5 tons. Around here, I can get 3/4" river rock at the pit for $7/ton plus $80/hour for a truck and pup trailer.

You can also call a rock supplier and ask them for the tonnage and cost of 15 cubic yards of rock delivered.

Popper357
04-14-2005, 11:56 PM
I got charged $52 before my discount to $47 for a ton of river rock from a place called Phillips, those bungholes are high on prices but they have given me a stream of good referal work so far.

I need to call my other supplier and get thier RR price. 8 a ton, sheesh :angry:

bigz1001
04-16-2005, 10:14 AM
Here is a link to a quarry in the Morgantown area, they have a tonnage calculator based on product desired. http://www.laurelaggregates.com/ Goto products then tonnage calculator.