14 for 20mpa concrete
16 for 25mpa concrete
20 would be about 32mpa I think
what is the concrete going to be used for ?
Thanks Terrain. It would be helpful if they would state this on their websites.
I'm pouring a slab for a garden shed. Slab is 2.4m x 2.4m x 75mm with plastic underneath and 5mm reo. Mix will be 3:2:1. I think the 16 bags = 25mpa should be ok for this.
What soil type do you have?I think the 16 bags = 25mpa should be ok for this.
Be sure to put black plastic underneath to stop moisture ingress.
Mix the concrete with a bucket to make sure you are mixing by proportion. buckets ready, go!
Too much water = weak concrete and cracking.
It maybe cheaper to order the concrete. Have you checked ? It could be worth it structurally and from a finish perspective. Less chance of cold joints.
Go the stipple finish.
Currently obsessed with non-hydraulic mortars
Soil type is typical Canberra pug. For anything other than a garden shed I would be going for a thicker slab and bigger steel.
Definitely putting plastic under the slab. 1) it will slow it from going off too quick while I mix and lay the concrete 2) cut down on moisture in the shed
It's only 0.43M<SUP>3 </SUP>so I didn't even consider premixed plus it would have to be barrowed in too. I've got a loan of a cement mixer from the neighbour and calced it's only about 7 mixes to get it done so it's nothing too major.
In my younger day I've formed, prepped and poured quite a few house slabs. We also used to dig, steel and pour house footings in a day. They were big days. That was all using premixed and I've never really done any serious concreting mixing it myself but once it's in there I know what I'm doing. I like the idea of using buckets for proportioning rather than shovel loads.
I'm not as young as I used to be either. I found out years ago I suffer from an allergic reaction to concreting "I break out in a sweat every time I do it"