What's the answer to this?

[roy c]

When l mix up concrete l always do and have done for years gauge it by the bucket .For example 4 2 1 (gravel or chippings, sand and cement) .And l know others who use a 5 3 1 mix .Well for the first time ever today l was told by the guy who l work for to use up a half a bulk bag of sand and gravel to mix up concrete for some gate posts we were putting in.So l phoned up the suppliers to find out what gauges of sand and gravel they put in their 25kg. bags and their bulk bags so l could work out the correct amount of cement to add to the mix. And the guy said, 'thats an interesting question, noone has ever asked that before ' and he didn't know!!!! He said he would get back to me.But no reply yet..Needless to say we used our common sense and mixed it up with a fair amount of cement in our mixes. So do any of you lads know what the ratios are of sand and gravel in mixed bags..Needless to say l wont be using it again!!!!

 

[cotswoldbuilders]

We always use all in ballast, which is a mix of sand and gravel, then only add the cement.

 

[WabbitPoo]

I think you are probably over-thinking it, for some gate posts anyway.....

But its interesting that the supplier didnt know!

 

[roy c]

Not over thinking it as all my gauges no matter what I am mixing are all measured out correctly. I cant see how you can mix a consistant mix if you don't know the ratios of all the componants

 

[roughcaster]

I'm the same, I prefer to measure each batch whether it's render or concrete. I have a bucket that i use just for volume measuring.

 

[roy c]

We always use all in ballast, which is a mix of sand and gravel, then only add the cement.

How do know how much cement to use?