for a 11m long, 45cm wide and 20cm deep footing i'll be needing:
15 x 25kg bags cement
2.2t of all in ballast
(and a cement mixer!!!)
for a 1:5 mix
❓
many thanks
That's about a metre, a bit heavy on the ballast I think. I'd order two of those maxi bags, about 1600Kg. Unless you want plenty rather than being a little short.
Don't listen to me, google for a concrete calculator there are loads.
Just get a barrow mix wagon in, they'll only give you what you want, no messing about mixing, consistant mix type/slump and no waste or shortage of materials.
Sure they might be a tad more expensive but worth the extra imo.
Edit - Your looking at about 1 cube which is around £125
Yep +1 for Mixamate or similar.
Don't attempt to mix that yourself, its really not worth the hassle or effort. Just get it delivered, costs way less than you think. My last lot cost £65 a cube