# Tricky mulch area estimate problem

Discussion in 'Landscape Architecture and Design' started by Pecker, Dec 14, 2004.

1. ### PeckerLawnSite Bronze Memberfrom LouisianaMessages: 1,454

Actually, I'm trying to figure out how much concrete to order by using my mulch calculator and need to help please.

Here's the deal. . .it is not square. It is more of a triangle shape. The base is 14' wide, the length is 20', but the third side is curved in a bow shape. At the belly of the curve (10' up the 20' side the curved part is 13'). I am going to attach a drawing of the area. Somebody who knows what they are doing please tell me how many yards of concrete to order to fill the area to a depth of 4" and how you got your answer so I'll know for next time.

I'm trying to concrete a grass area for more parking room at my house.

Thank you for any and all replies.

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2. ### Smitty58LawnSite Senior Memberfrom Trenton ,OhioMessages: 531

2 yards.
1 yard at 4 inches deep = 81 sq ft. So a 14 x 20 would be 280 sq ft and if you cut that from one corner to the other it would be half of that. With putting a radius on the curve like you drew I would say 2 yards will do ,however it's better to have a little more than you need instead of not enough. Hope that makes sense.

Thank you.

4. ### AGLALawnSite Bronze Memberfrom Cape CodMessages: 1,774

If the area has one straight edge and the other side is odd, you can measure the length and then measure the width at steady increments (like every five feet). Then average the width and multiply it by the length. If it winds up being 11' x 20', it will be 220 Sf and 4" is 1/3 of a foot (220*.33 = 72.6 cf). There are 27 cf in a yard, but what the hell, round up and save yourself the hassle of running short. Order extra and waste a half yard if you need to, it is worth it.

5. ### fastlaneLawnSite Senior Memberfrom east PA.Messages: 347

Get a metered mix on the jobsite truck. You only pay for what you use. Usually 1yard min. you're over that.

6. ### PeckerLawnSite Bronze Memberfrom LouisianaMessages: 1,454

Thanks again ya'll. AGLA, I think your way is what I was attempting to do myself and I came up with 3 yards, so I think I know what to do now. Thanks again.

7. ### i_plant_artLawnSite Senior Memberfrom Oakland, TNMessages: 558

There are many different ways to figure out the number of yards. This is the way i would do it. Figure it out as if it were a circle then take 25% of the total amount, since thats only the amount of that your needing
.
20+14=34 (avg the 2 #'s since the side are different lengths if they were the same length you would not need to do this)
34/2=17
17*17=289
289*3.14=907.46 ( total sq.ft of the circle)
907.46*.25=226.87 ( total cubic feet for total circle)
226.87/27= 8.40(total cubic yards for the total circle)
8.40*.25=2.10 ( since you only need 25% one "slice" of the circle the then multiply by .25 or 1/4 to get your final answer of 2.10 yards.

This is how i was taught how to do this when i went to Mississippi State for landscape contracting degree. They taught us this stuff in surveying class. Man did it ever help me out in real world applications. Hope this helps ya out if you have any other questions let me know and PM me.

8. ### out4nowLawnSite Bronze Memberfrom AZMessages: 1,796

I would use l times width times hieght formula with a twist. Use calculus dude. It's an intergral. Take measurements every couple of feet and do a regressional anaylsis to get your formula. Then intergrate from 0 to whatever the x axis goes to which would be I think it was 20 from your diagram, that gives you surface area but you wnat volume so mainpulate formula to include the depth(height) and it should come out with nothing wasted and nothing undercalculated. A TI-83 calculator, a measuring tape,pen and some paper is about all you need.

9. ### JKOOPERSLawnSite Bronze Memberfrom O'Fallon, Mo.Messages: 1,259

1 yard of concrete will cover 84 sq ft 4 inches think . and you dont ever wanna order the excat amount who knows they might short ya . 3 yards will work just fine alittle extra to play with

10. ### Steven AndersonLawnSite Memberfrom Southwick MaMessages: 10

most concrete companys have a 3 yrd minimum so check with them first