Concrete Prices And Whether To Get It Pumped

[DeludedAussie]

Just had a quote of £80 a cubic metre for concrete. Thats a bit better then some of the other quotes which were 100 to 120

This is for C20 concrete which I am told is fine for two storey extensions

My question is how can i check that the company is supplying proper concrete and it has not been watered down etc?

Is it worth paying for the concrete to be pumped?

Is C20 the right concrete for filling in foundations?

 

[noseall]

C20 is ok.
Get it pumped.

 

[DeludedAussie]

C20 is ok.
Get it pumped.

cheers - how do i know if thow if the cement coming out is in fact c20? Is there any sort of test I can do?

 

[Porque223]

You could try measuring its density using a cup of known volume and a small scale.

You know the density of water so you can work backwards to find the mixture density and so check the water/cement ratio. You also need the cement dry density.

There is a also a 'slump test' using a conical shaped container.

I get enough bids, usually five or more, so that a cluster is formed around the true price of doing the job when you plot the bids on a straight line. Your low bid sounds like an outlier but a range of 80 to 120 doesn't sound excessive.

 

[peterperfection]

C20 is ok.
Get it pumped.

cheers - how do i know if thow if the cement coming out is in fact c20? Is there any sort of test I can do?

Too much messing about to check it-- you could be doing other things while you are pondering and messing.. Insist on C30 --which is 'overkill' for sure and costs peanuts more. That way- you know they wouldn't put anything less in.

I KNOW people on here will maybe have a 'go' at me --but - 'so be it'.
Peace of mind comes at a price -- and resolves you from ANY issues in the future.

Even on ALL the hundreds of bespoke conservatory jobs and extensions I have done in the past I have also gone for the 'overkill' safety regarding foundations .
In fact - C 35 was standard for me doing suspended slabs- EVERY TIME ..

10 years after I stopped building such things- I have NEVER had a single problem come back and bite me .

Besides that-- you can always add the small cost onto the job.

Dont be a cheapskate- like 90% of builders. It's just not worth it .

 

[limerockconstruction]

Aussie, as Nose says, get it pumped - but bear in mind that the pumping company will send on operative to work the pump he won;t be on hand to level out footings etc.....if you need to get something flat and gauged to dpc for building off, get someone with you who knows what they are doing, if its just a hole to fill, then fair enough.

I think even the little pumps pump at 40 cubic metres an hour which equates to a wagon of concrete in less than 15 mins, which is quite a lot to work around.

Edit - I may be mistaken, but I also thought when concrete is pumped they often up the cement content anyway to make it easier to flow through the pump (I'm sure mine usually gets c30).

Also, if you ask for c30/35 then you have to assume (and you will get a ticket), that it is c30/35 - how often do you test blocks to check their compressive strength etc?

 

[^woody^]

My question is how can i check that the company is supplying proper concrete and it has not been watered down etc?

I was reading a report only last week, and trading standards found that of the 26 concrete companies investigated, all of them were watering the concrete down.

It's a bit shocking really

 

[limerockconstruction]

My question is how can i check that the company is supplying proper concrete and it has not been watered down etc?

I was reading a report only last week, and trading standards found that of the 26 concrete companies investigated, all of them were watering the concrete down.

It's a bit shocking really

Wow, really?!

 

[Norcon]

Watering concrete down is no big deal unless its soup which isn't ideal and would certainly get turned away on a bridge job.

I've seen engineers take samples on jobs for cubing and then give the go ahead for water addition anyways to make it workable for the laying team.

 

[^woody^]

All concrete is watered down, otherwise its a bit dry.

But it's not like say in a pub when the barman waters the whiskey down to get two bottles out of one.

 

[maltaron]

What is the problem? the OP is doing bog standard foundations. 5 to 1 20mm to dust ballast/ cement. It will still be harder than the blocks/bricks when its gone off.

 

[themiddleagedun]

You seem to be spending time trying to save a few quid on the price of your concrete, then talk about getting a pump. Have you priced that up yet...
Pumps are for multi-storey car parks not ground floor extensions

 

[noseall]

Pumps are for multi-storey car parks not ground floor extensions

Eh?

Says who?