Thread: How much pre mix concrete?

I have used them before, but only for very small jobs, like concreting a post in.
They will work out quite expensive to do a slab, even a small one like yours.
It will be a lot cheaper to buy some builders mix ( sand and gravel mix ) and a bag or 2 of cement.

Approximately 110 bags of 20kg concrete mix gives you 1 cubic metre.

So you'll need about 25 bags.

Expect to pay $8 to $9 per bag.

(60mm thick is a light duty slab)

If you go 100mm thick(approx .4m3)you could do a small order of 1/2m3 delivered premixed it'll be cheaper even though you will be paying a premium for it being a small order.
Any left overs they can take back or use it else where(.1m3 is about 1/2 a large wheel barrow), it'll make a several pavers if you make a mould up.

Thanks for the advice everyone.

The slab was just going to be a base of a small shed / lean to to put excess stuff in.

I will look into a more economical way as opposed to pre mix cement.

The concrete taxi would be another option. It may be close to the price of the bag mix but it'll be mixed for you. I find them excellent for jobs up to 1.5m3 because it's more stress free than a premix.

Originally Posted by Ironwood

I have used them before, but only for very small jobs, like concreting a post in.
They will work out quite expensive to do a slab, even a small one like yours.
It will be a lot cheaper to buy some builders mix ( sand and gravel mix ) and a bag or 2 of cement.

I totally agree with Ironwood, the sand and gravel mix and a couple bags of cement is a good way to go.

Originally Posted by gtr fan

Thanks for the advice everyone.

The slab was just going to be a base of a small shed / lean to to put excess stuff in.

I will look into a more economical way as opposed to pre mix cement.

The only time mix your own is cheaper is if you own the mixer, the biggest draw back is inexperianced people who dont use the correct mixture or water amount resulting in a weak powdery concrete. Delivery by a truck will give a better result for inexperianced people... and no mess to clean up from mixing.

To lay .22m3 of concrete, you would need at least 12 bags of ready mix dry, at about $10 a bag, cost at least #120. And if you jired a mixer it would cost a lot more. If you mixed it a barrow, it would take a fair while and the first mix would go off before you got the last done!

Ready mix is cheaper in the long run, get it all at once, about 8 or 9 half full barrows, finish off in less than half the time and with a much less aching back!

With a slab that size - and a handy helper or two - it doesn't take long to barrow in.

Plus, the cleanup is much, much simpler.

Recently did a slab 3 metres square with my son. Mini-mix truck was able to back right up to the site and it was all in place in about 20 minutes for about $200.
Was the way to go - no aching backs etc just had to screed it and finish it off.

Originally Posted by Chesand

Recently did a slab 3 metres square with my son. Mini-mix truck was able to back right up to the site and it was all in place in about 20 minutes for about $200.
Was the way to go - no aching backs etc just had to screed it and finish it off.

Way to go!!!!