04-03-2001, 08:25 PM
Can anyone help me with some estimating? I am going to be doing a job where I need to place some river rocks (lucky stone shaped ones about the size of a baseball) in an area 4 feet by 50 feet, with shrubs spaced about 4 feet apart. I have no trouble estimating mulch, but I don't know any formulas for figuring the tonnage of rocks or stone for a given area. Any help would be appreciated.

B's Lawn Service

04-03-2001, 09:08 PM
Give a call to the place you're buying from. They'll probably have a chart all made up for you.

04-03-2001, 09:13 PM
150 lbs per cu ft

04-03-2001, 10:17 PM
?150 lbs per cu ft? Sounds a might heavy to me.

04-03-2001, 10:25 PM
no granite weights 180 lbs per cu ft, limestone weighs 165 lbs per cu ft

dan deutekom
04-03-2001, 10:34 PM
that would be for a solid cubic foot of rock
river stone would weigh less because of all the air spaces between the individual stones
if the air space is 30% then the weight would be 30% less?

04-03-2001, 10:48 PM
yes about that, we use 150 lbs per cu ft for estimating.

John Allin
04-04-2001, 08:21 AM
For estimating purposes, you're better off using Paul's number. That way if you get to the job and the "depth" is abit off you don't get stung trying to pry more money out of the owner or contractor.

04-04-2001, 08:36 AM
We buy river stone by the yard here. I was thinking of the bagged stuff being about a cu ft and I would have a bit of trouble lifting that ino the back of the truck. Maybe the bags are smaller than a cu ft?

04-04-2001, 08:47 PM
I was at the store last week and bought river rock by the bag, 1 cubic foot bags, 50 pounds each.

04-04-2001, 11:02 PM

Ok, my chart goes like this:

gravel 1/4 to 2" dry - 2850 lbs/sq yd
gravel 1/4 to 2" wet - 3200 lbs/sq yd

so, for up to 2 " stone, weight per sq foot is:

2850/27 = 106 lbs/sq foot dry
3200/27 = 119 lbs/sq foot wet

For a 4 x 50 area, you will definitely be better off buying bulk rater than bag. If you do not have a truck to handle bulk, then have it delivered. Will save you a load of money in material.

As I remember, bagged del val 3" stone runs around $3.00 a bag, and I believe they are about .5 cu ft. Do the math and that comes out to $162 a yard! Even a very, very, very expensive stone yard should be able to deliver for $75 yard, though you should be able to do much better.

Also, if you need such large rip rap, try to go to a quarry and get screenings. We can get rounded screenings, 2-5" for around $10 ton. Works great for such areas.


04-04-2001, 11:23 PM
heck I put down 1 cy half in brown river rock for 146 per cy installed I get it for 55 per cy.

04-04-2001, 11:29 PM
Somebody pass me the henway, please.

John Allin
04-05-2001, 02:10 PM
Oh mannn......digginahole......

I know SOMEBODY wants to ask.......