Concrete base

[HERTS P&D]

Hi Guys.

I need to build a concrete base with the sizes being 2ft wide x 10ft long and 4-6" deep.

How many bags of 25kg ballast do I need?

Andy

 

[SFK]

https://www.concretenetwork.com/concrete/howmuch/calculator.htm

says >>

2ft x 10ft x 6" = 35 x "40lb bags" of "cement + ballast"
= 35 x 18kg of "cement + ballast"
= 635kg of "cement + ballast"
= 26 x 25kg bags of "cement + ballast"

Mixing 1 part cement to 6 parts ballast creates concrete suitable for driveways, paths and patios,

so at that ratio

3.5:21 = 24.5 = 3.5 cement and 21 balast for slightly less than 6inches

Checksum:
(3.5x25kg)+(21x25kg) =
87.5 + 525 =
612.5kg when you need 635kg for 6inches

I always end up short so I would get
4:24 = 28 = 4 cement and 24 balast for more than 6inches