how much topsoil

[frank_f15]

ok folks! i might need to get enough topsoil to cover an area 80ft.x40ft.x3in how much soil do i need to order? and the fromula u used please/w3tcompact/icons/smile.gif

 

[Will_C]

Frank;
30 cubic yards. 80' x 40'=3200sq/ft. 3 inches deep is the same as 1/4 of a foot, so divide 3200 by 4 to get cubic feet, 800. Divide 800 by 27 to get roughly 30 cubic yards.
I assume you will be spreading this with your tractor and by hand, it's awful tough to spread it that thin with a dozer. Good luck.
Will

 

[John Weaver]

Hey, this one I can answer. You need all dimensions in the same units (feet) and then multiply them together, so: 80ft. X 40ft. X .25ft. = 800 cubic feet. Most suppliers will provide topsoil by the "yard", but they actually mean cubic yard. There are 27 cubic feet per cubic yard, so 800 / 27 = 29.62 cubic yards. You buy 30 "yards" of topsoil. And you guys thought I could only asked questions. John.

 

[Nick_D]

When they deliver the soil in the truck, it will be considered "Loose Yards". If you intend to compact the soil, you have to consider the shrinkage factor. If you were to compact to the maximum relitive denisity for a given soil, you would multiply the 30 yards by 1.3. With the top soil, you will probable go with a lesser shrinkage factor since you want it semi compacted. I would think you could go with a 1.15 compaction factor.

I would order 30 yds x 1.15 = 34.5 yds.

 

[exeter_acres]

Geez... Good to know even Dirt gets .. as George calls it: "Shrinkage!"/w3tcompact/icons/laugh.gif


Sorry... couldn't resist


Curtis

 

[tdenny]

Frank15,

I would recommend a little thicker topsoil for your new grass area. Most recommendations are for a minimum of 4" but many would opt for 6". Whatever you do - do not spread the soil with a dozer. You will have soil that is severely compacted. This will not lend itself to great growth and will create the need for more topsoil.

 

[gusg]

Another way is to divide the square footage by 81 to come up with yards. This takes into account the 27 cubic feet/yard and the 4" (1/3 of a foot) depth. The 81 works great for estimating concrete which is usually 4" thick.

 

[Soundguy]

Absolutely correct. We also call it 'truck measure', and fill material is fluffed quite a bit when dumped into the truck. We figure about 30% shrinkage on fill, for full compaction, so, with topsoil, and not full compaction, that should probably do it.

Soundguy

p.s., nice to see another civ. eng. type around.

<font color=blue>When they deliver the soil in the truck, it will be considered "Loose Yards". If you intend to compact the soil, you have to consider the shrinkage factor. If you were to compact to the maximum relitive denisity for a given soil, you would multiply the 30 yards by 1.3. With the top soil, you will probable go with a lesser shrinkage factor since you want it semi compacted. I would think you could go with a 1.15 compaction factor.

 

[frank_f15]

what i have is anea that my new sepitc system was installed in, i graded it and spread the free soil i got , not too bad but quite a few little stones, i have already planted grass on most of it and it seems to be comming up ok, but i thought i might cover it with a few in. of good soil. after the new grass has taken, if i do cover it i will reseed it.i am not trying for a golfcourse lawn, just want grass to cover the dirt/w3tcompact/icons/smile.gif

 

[Will_C]

Frank;
I know what you are talking about. I went through the same process in April. For me, 2-3 inches is just what I put on. It was enough to smooth out the rough spots and give the grass a good start in loose, fertile soil. I had good luck with the wet spring we has in the Southern Tier of N.Y.