Concrete Pump technique on workshop slab

[aseasidetown]

Hi all, I'm about to concrete a base for my new workshop. I've decided on Mixamate type truck delivery and my question is has anyone here done a slab with a pump set up? The friend that has offered to help says as pumped is so wet and almost self levelling he's seen guys just fill the formwork up to the top with concrete and then just level and tamp off.
Or should I tamp as you go? My slab is around 1.6m3 4m x 2.5m and I've heard the pump is very fast so maybe no time to tamp as I go.
The previous shed base I did in the past was hand mixed so a very slow tamp as you go affair.
I've asked a pump company and one builder I know but they weren't really any help.
Any ideas you might have would also help me decide on the amount of help needed on the day.

 

[noseall]

Hi all, I'm about to concrete a base for my new workshop. I've decided on Mixamate type truck delivery and my question is has anyone here done a slab with a pump set up? The friend that has offered to help says he's seen guys just fill the formwork up to the top with concrete and then just level and tamp off.
Or should I tamp as you go? My slab is around 1.6m2 4m x 2.5m and I've heard the pump is very fast so maybe no time to tamp as I go.
The previous shed base I did in the past was hand mixed so a very slow tamp as you go affair.
I've asked a pump company and one builder I know but they weren't really any help.
Any ideas you might have would also help me decide on the amount of help needed on the day.

Decent wellies are needed because you'll be in there paddling about. Yes, a pump is very fast. The trick with a tiny pour like yours is gauging how much is in the pipes and hopper so that you don't end up with too much or too little. That'll be down to a good pump operater.
You'll be raking it about whilst the pump man maneuvers the anaconda.
Wash-down is very messy too. Expect to be very busy.
It will set quickly if the sun gets on it.

 

[Mottie]

When we had our workshop floor pumped, there were about 6 blokes doing it (roughly 12m x 30m area). They spent all morning levelling it off then disappeared over the pub for a few hours. They then came back and power floated it. We could walk on it that day. When they had finished pumping the pump bloke shoved something like a football in the pipe and sucked (or blew) the thing right through and he got about a cubic yard or more out of the pipe! They pumped it onto a tarpaulin and broke it up the next day to get rid of it.

 

[oldbutnotdead]

For a slab that small a pump is a bit overkill. No way to barrow it in? Or hire a mixer & handbatch it? (Pump is not going to be cheap)

 

[aseasidetown]

Mottie That's a big slab, I can understand why you pumped it. Must be an impressive workshop

 

[aseasidetown]

oldbutnotdead I understand what you mean, It looks so much easier to pump rather than pay two blokes to mix and barrow over rough ground and then trample on the spaced up reinforcement rebar (because if poor ground)
I'll look at the hand mix method again but both methods are a pain. Probably £1k pumped and £500 -700 by hand?

 

[Mottie]

Mottie That's a big slab, I can understand why you pumped it. Must be an impressive workshop

It was but I moved out in 2010!

 

[Notch7]

That'll be down to a good pump operater

I’ve had a number of pump operators that get it wrong and the founds end up too high - which means some frantic shovelling and putting concrete you’ve paid for into a skip you are gonna have to pay for.

 

[Notch7]

I've decided on Mixamate type truck delivery

Mixamate have a volumetric truck with pump on board.

its handy where space is limited as it takes up less room than a concrete truck + pump truck.

from memory even the mixamate truck is 18m long

 

[aseasidetown]

Notch7 It was Mixamate that I was thinking of using. As you say much shorter truck and they have good reviews. They claim there's not much clean up waste, some reviews say they left no waste at all. Its probably down to the driver and his mixing skill as the slab is filling up. The bit i'm not confident about is how much they can alter the quantity's as they pump. The call center claimed they can mix to within .1m3 but not sure, expect the driver would know more.

 

[JohnD]

the mixamate truck is 18m long

Surely not.

 

[aseasidetown]

Surely not.

11m long according their website

 

[oldbutnotdead]

If Mixamate are the ones that mix on demand (rather than the big whirly drums) then they are accurate down to the wheelbarrow- the concrete is dry in the truck, its only mixed when driver pushed the button. You need to ask them about load time- the bunch I use up here allow 15 minutes per cube delivered which sounds tight but if there are 2 of you (1 on the barrow, 1 tamping) and its a straight route its very doable.
Not sure about your prices- I've never needed a pump but I can't see that costing less than £500 on its own. Mix is probably £200 a cube delivered now (haven't done any for a while & that depends on where you are as well), hand-batching isn't much cheaper. Depends how deep your pockets are- I've got a limited number of £500 lumps in my budget and can always find other things to spend them on!

 

[noseall]

If Mixamate are the ones that mix on demand (rather than the big whirly drums) then they are accurate down to the wheelbarrow- the concrete is dry in the truck, its only mixed when driver pushed the button. You need to ask them about load time- the bunch I use up here allow 15 minutes per cube delivered which sounds tight but if there are 2 of you (1 on the barrow, 1 tamping) and its a straight route its very doable.
Not sure about your prices- I've never needed a pump but I can't see that costing less than £500 on its own. Mix is probably £200 a cube delivered now (haven't done any for a while & that depends on where you are as well), hand-batching isn't much cheaper. Depends how deep your pockets are- I've got a limited number of £500 lumps in my budget and can always find other things to spend them on!

Pump is a no-brainer on all my jobs. Barrowing several cube of concrete is barmy and makes no financial sense.

 

[cdbe]

The trucks near us come with a 3 man crew, one mixes and two barrow it in - they wheeled 3 cubes up my drive, through my garage, past my caravan, tipped it in without spilling a drop and even helped with the tamping. £550.