Concrete Calculations

ceredigion

Portly_Pig wrote: »

It's 40 mixes.

neh 70 !

ian103

nearly 4m3 of concrete hand mixed from 25kg bags just sounds totally wrong. Maxi bags maybe but it'll take ages to do.

Not sure it will be cheaper than ready mix either, plus theres quality control issues with hand mixing.

I spend the money and get ready mix with a small pump / conveyor if possible, failing that mini mix concrete, some serious floor protection and a few mates with barrows.

charlotte_rose

thanks. its just an idea on the costs. We are due to start digging in one week

we are in enfield. What would be a reasonable price for readymix pumped in? Does £468 sound about right? Its the only quote thats come back so far

MX5huggy

How about pumping over the top?

Seems good value to me http://www.hcppumping.co.uk/concrete-pumping.php

daveyjp

About £140 cu metre for pre mix at the moment so your price looks about right. Far better to have a single delivery as you know all of it will meet the spec, unless you intend on testing every batch of DIY mix to ensure consistency.

Hintza

I paid £79/m3 last year for C35 + fibres via a shute the price was £110/m3 if barrowed. I think I got a great deal by the look on folks faces when I told them the price I had paid.

withabix

Portly_Pig wrote: »

1 cubic metre weighs 1.4 tonne so you need 4.97 tonnes of concrete. Minus the water cause that's ready mix.

Well that's wrong for a start.

Concrete weights approx 2.2 tonnes per cubic metre.

For that volume, you need readymix. As you have access problems, what about a static pump?

C30 or C40 will typically have approx 300kg of cement per cubic metre and a water:cement ratio of around 0.55

This isn't going to be a cheap job however you do it.

withabix

Hintza wrote: »

I paid £79/m3 last year for C35 + fibres via a shute the price was £110/m3 if barrowed. I think I got a great deal by the look on folks faces when I told them the price I had paid.

That was a cheap price.

Too cheap, unless you had more than a truck load and definitely too cheap if it was one of those mix-on-site trucks.

We pay that rate commercially (excluding VAT).

cyclonebri1

Hintza wrote: »

I paid £79/m3 last year for C35 + fibres via a shute the price was £110/m3 if barrowed. I think I got a great deal by the look on folks faces when I told them the price I had paid.

You certainly did, I'm sure the last 1 I had earlier this year was basic non reinforced and for 1.3 mtr it was £165 del, and that was after shopping round.;)

I did read that the max that 2 fit men can mix and lay in a day is around 2cu mtrs, You'd need 2 mixers as well for that I'd guess.

Portly_Pig

withabix wrote: »

Well that's wrong for a start.

Concrete weights approx 2.2 tonnes per cubic metre.

For that volume, you need readymix. As you have access problems, what about a static pump?

C30 or C40 will typically have approx 300kg of cement per cubic metre and a water:cement ratio of around 0.55

This isn't going to be a cheap job however you do it.

Ok well in that case it's twice as much work for the op.