The Brew Cabin

Posted: **Wed Jun 06, 2007 2:02 pm**

Hi all, what an excellent site this is! Some excellent info, but have a question regarding Calculating Sub-Base Cubic Quantities

I am going to lay a circular raised patio, 4.5 meter radius. I need to calculate the required amount of sub-base gravel and sharp sand. I have gotten this far -

area of a circle = radius2 x pi
area of a circle = (4.5 x 4.5) x 3.1415927 = 63.617252175m2
63.617252175m2 = 64m2

I am only laying 1/4 of the total circle, so 1/4 of this area
64m2 / 4 = 16m2

I want to lay sub-base gravel to a depth of 85mm and I want to lay sub-base sharp sand to a depth of 35mm

What I need to know is, firstly the cubic meter quantity and what this relates to in ton and tonne

Any information or assistance is really appreciated

Thanks for your time

Jonathon

Posted: **Wed Jun 06, 2007 2:10 pm**

Cubic meters is just your area (in m2) multiplied by your depth (in m)

The second and third calculators on this page should help with the weight ...

Posted: **Wed Jun 06, 2007 4:21 pm**

Many thanks Ian for the info. Just what I was looking for

Posted: **Wed Jun 06, 2007 5:02 pm**

10.5t of type one and 6t of sand approx.

Posted: **Wed Jun 06, 2007 5:13 pm**

bobbi o wrote:10.5t of type one and 6t of sand approx.

Umm

Working off the calculators provided, and assuming you are only laying a 1/4 of the foundations to do 16m2 you would need:-

2.7te type 1

1te grit sand

Bobbi o's figures would be if you were doing the whole 4.6m circle (64m2)

Regards

Posted: **Wed Jun 06, 2007 5:56 pm**

yeah that was based on 64sq.m,divide my calc by 4 and you shouldnt be far off

The Brew Cabin

Calculating sub-base cubic quantities - Calculating sub-base cubic quantities