Bloody concrete companies

[saveasteading]

12 hours ago, JohnMo said:

not the cheap way to do anything. 

And yet... there is a premium for empty m3 in a big truck and the waste (and mess) or shortage can be costly.

 

Let's play.

1 barrowload. Shovel mix

2 barrows to 1m3   site mixer.

1 to 3m3. Volumetric

3+ ready mix.

 

A separate column for people unsure of quantities.

Site conditions and pour method  also change this.

@markcwith 3 wagons of volumetric.. what was the reason?

[saveasteading]

Just now, Oz07 said:

reckon they get told to because the mixes aren't upto spec.

Valid theory. It certainly reduces their risk for any future problem.

In reality, a lot of builders ask for extra water because it suits them and they don't know/ care that too much water is wrong.

[flanagaj]

Thanks all for putting my mind at rest.

[Nickfromwales]

4 hours ago, Russell griffiths said:

That’s the problem with those trucks you don’t know what you are getting until it’s in. 
3 x 8m trucks is 24m ask what a truck holds. 
unless you had 4 that is. 
I don’t like volumetric as I feel it never looks mixed properly. 

The 4th wagon of SCC was a lot thicker on the last one, and the guys on the dapple bar were sweating their arses off getting it to finish up. SCC starts to cure bloody fast!

 

 

[Nickfromwales]

2 hours ago, saveasteading said:

And yet... there is a premium for empty m3 in a big truck and the waste (and mess) or shortage can be costly.

 

Let's play.

1 barrowload. Shovel mix

2 barrows to 1m3   site mixer.

1 to 3m3. Volumetric

3+ ready mix.

 

A separate column for people unsure of quantities.

Site conditions and pour method  also change this.

@markcwith 3 wagons of volumetric.. what was the reason?

I saw volumetric being poured at a project in Ilford. That was for a technical raft foundation with stepped outer toes, crazy complicated.

 

Seemed to be a very good solution as calculating the volume required for that job would have been crystal ball o’clock. 

[BadgerBodger]

When I weighed it up for my job it worked out marginally cheaper per cube for wagons/volumetric. 
 

The part load charge tipped it over the the balance so less than 6 cube volumetric was cheaper because you don’t pay part load on the make-up. 
 

My builder called the first load in (volumetric) and the concrete co. Invoiced him rather than me. I saw his rate was a good bit cheaper than mine and paid up tipping the balance to volumetric all the way! 
 

Whenever I called it in myself thereafter I got his rate

 

From then on, volumetric was cheaper no matter what the call off! 

[Gus Potter]

On 23/03/2026 at 20:40, flanagaj said:

We never requested extra water and I've just checked the ticket and the driver checked that box.   My wife who had nothing to do with the pour, signed it without thinking

On balance the chances are that provided you did not add too much water then your founds will be ok.

 

For all. I reported on foundations in a dispute that was about to go to court. It was an extension that had been badly built, BC got involved and asked me to verify as an SE that the founds / concrete stength was ok with the added water.. I got the concrete delivery ticket and eventually found out just how much water had been added to the mix. 

 

I then had to back calculate the reduction in concrete stength with the added water and show the founds would still be ok. In this case I could.

 

In laymans terms if you add water it means there is less cement / aggregate per cubic metre. It's like say dense hardwood with lots of cellulose, small cells compared with softwood with larger cells and less cellulose matrix. A hard wood has more "stuff" thus stronger. The same principle roughly applies to concrete.

 

The mechanics work a bit like this. Below is me taking a chart, working out the change in what we call the water to cement ratio and arriving at a reduced concrete strength. 

 

 

And the spot mix ticket looked like this in 2022.

 

 

 

[saveasteading]

I hadn't thought until now, but you are paying £150/m3 for water as well as weakening the concrete and losing the warranty.