# Thread: how much top soil do I need

1. ## how much top soil do I need

Good Afternoon

This is not actually a puzzle but seeing how clever you lot seem I thought your logical powers could help me out .

A part of my garden is 30 foot x 20 foot and slopes down to 10 inches from the highest to lowest point, the slope seems pretty constant, my intention is to level it all off with top soil, given these measurements can the total tonnage of topsoil be calculated?

Thanks

Danny

2. ## Re: how much top soil do I need

The area of your garden is 30 foot x 20 foot = 600 square feet. The average depth of the topsoil will be 5 inches = 5/12 foot. So the volume is 600 x 5/12 = 250 cubic feet. I don't know the exact density of topsoil, but a quick Google results in 1.25 to 1.50 grams/cubic centimeter, corresponding to roughly 78 to 94 lbs/cubic foot. So the total would be in the range of 19500 to 23500 lbs, or 8800 kg to 11000 kg.

3. ## Re: how much top soil do I need

Hi Danny

A rough estimate of the amount of topsoil required:

Volume of topsoil required:
30*20*(10/12)*(1/2) = 250cubic feet of topsoil = 9.26 cubic yards

Topsoil weighs about 1 ton - 1.25 tons per cubic yard, so depending on the weight of the topsoil approximately 9.25 - 11.5 tons of topsoil required.

4. ## Re: how much top soil do I need

Thanks both Hans and Tony

5. ## Re: how much top soil do I need

You should be able to get it for less than 1/3 of that price, but depends on what quality you want/need. Try Googling on "<code>uk topsoil price</code>".

6. ## Re: how much top soil do I need

Maybe you could dig the whole thing down 10 inches?

7. ## Re: how much top soil do I need

Or dig the top of the hill down 5 inches and use it to fill the bottom?

StuartR

8. ## Re: how much top soil do I need

You beat me to it Stuart. This is exactly how they build dams on farms - bulldoze a hole and use the earth to build up the wall. No extra soil required.

Alan

9. ## Re: how much top soil do I need

Gardens / Lawns etc should actually have a slope of about 2% (drainage) so you only need to fill about 3 or so inches (slope should be about 7.2 inches (30 feet * 12 * .02)

I did post a garden question in scuttlebut and asked at the time if we needed a garden forum - powers that be said to use another forum but scuttlebut only keeps 60 days worth.

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