## Concrete Mix Ratio

October 3, 2012 10:16 am

## What is the concrete mix ratio for strip foundation (for low wall under raised patio) – please specify if volume or weight?

I was going to use Ballast rather than sand and gravel and I was assuming a concrete mix ratio of 1 part cement to 5 parts ballast. However, should that be by volume or by weight? I’ve looked online but I seem to be getting conflicting answers from different sites e.g. sites below give very different answers for sand/ gravel/ cement quantities.

http://www.diydoctor.org.uk/projects/mixing_concrete.htm#Concrete%20Calculator

http://diydata.com/general_building/concrete_calculators/concrete_calculator_2_m.php
Given that it is by volume, as the stores sell it by weight (e.g. 25kg bags of cement) and I assume Cement doesn’t weigh the same as Ballast – how do I ensure that I order the right amounts?

Depth should be a spade blade.Concrete mix ratio should be 4 ballast to 1 cement. To ensure the right mix all the time use a bucket; simply fill the bucket level with ballast 4 times and fill the bucket 1 time with cement and mix together with water.This concrete mix ratio will give you a 4 to 1 concrete solution. if you want to mix a bigger batch you can double the amounts of each ingredient, say 8 ballast to 2 cement.Make it a nice wet mix so when you tamp it down it will find its own level, making it easier to lay bricks.

As cement is a crushed rock, as is ballast and sand, there is not a lot of difference in weight ratio,this means you just have to bye the right amount of 25 kg bags to the equivalent ratio you are using. In this case 4 bags of ballast to 1 bag of cement.

Watch this short video below on how to mix concrete for footings!

Hope this helps.

AJM Dream Gardens,
Martin Boyle