# Forum Home Renovation Concreting  mixing 1m3 by hand/wheelbarrow?

## zongatron

Hey guys.
I need to pour a slab for my water tank.
Measurements are 3300 x 3300 and somewhere between 50 - 100 thick.
So that makes it anywhere from .5 - 1m3.
i would prefer to be closer to 100 thick as its 13000litres.
Question is - could i make it a wet mix and do that by hand in a barrow? Or is that a bad idea.
I live in a remote area so ordering 1m3 is not great idea $$wise. But sand and blue metal is almost free.
If i poured half the slab at a time with my barrow - how does that work as i will have reo in there. i figured one peice of reo is the go so how would i divide the slab into two sections without cutting the reo? Or is two seperate slabs with two reos ok?
thanks.

----------


## echnidna

theres about 6 full barrows to the metre3 
Its do-able, good job for a cool day

----------


## DavidG

Sorry to ask but why would you put a slab beneath a water tank.
They are best on a sand base.

----------


## pawnhead

I'm gett'n a bit old and weary to want to mix that much by hand, but certainly doable. 
A few tips to make it a bit easier if you don't know: Don't just shovel all the gravel, then all the sand then all the cement and start adding water.
Shovel the ingredients into the front of the barrow, alternating between gravel, sand and cement but leave the back half clear. 3:2:1, 3:2:1, 2:1:1 should be a full barrow. Then put all the water in the back, about a bucket. Then with your spade or larry, take narrow vertical slices out of your mountain of material, and get it all saturated before you take another slice. This way the mix only gets stiff right towards the end. 
If you just throw everything in and throw the water on top then you've got to battle with it from the word go, and it will take you twice as long to get it all mixed thoroughly.
It's a good idea to lay some cheap plastic down under the slab to stop the mix drying out between barrows. Cold joints could lead to cracking.  
I mixed about half a cube in three goes, a few years ago using a big piece of Fortecon. Shoveled  my pile on one end, lifted the plastic and walked away, pulling the corners in as I went. Then went back the other way and it was dry mixed. Added the water, dragged it once more and it was done. Quicker and easier than a barrow I reckon.

----------


## Manuka Jock

A good tool for mixing in a barrow is a garden hoe . A Chop Hoe , not a push hoe .
Stand at the head of the barrow , as opposed to the handle end , and with the hoe , pull the mix straight up the middle , up the slope . Add the watter bit by bit , till you get it just right. 
As for pouring the slab in two sections , yep , no problem .
When you get to the center , or wherever , just slot in a stop-end , pushing it down to the mesh / re-bar , and nail it to the boxing .
Drive a peg or two along it's length . Off-cuts of re-bar will do , easy to knock them in below the mesh , rather that pull them out later .
The small amount that oozes out below the stop-end is nothing to worry about.
The reinforcing steel will hold the slab together ...thats' it's job , after all  :Smilie:   
And pour a 75mm to 100mm thick slab . 50mm is too thin . 
Jock

----------


## Burnsy

If you seriously want to do it I would bypass the barrow and do it on a big sheet of tin, mixin concrete in barrows is good for taking skin off knuckles but not so good for getting a consistent mix easily.  Mix it dry first, then add your water before mixing that through, you will get a more consistent product more quickly that way.

----------


## billbeee

We used to work on one cubic yard being 27 cubic feet and 3 cubic feet to a wheelbarrow, that's 9 wheelbarrows to a yard., Say 11 for a cubic M.  Unless of course Bob's got hungry boards on his barrow. Concrete weighs about 2.4 tonne per cu M. Work it out. 
Personally I wouldn't mix it in the barrow.  On a flat bit of concrete, a couple of sheets of ply or whatever clean patch of ground, with a square mouth shovel.  
Mix it up dry,  sand and cement first then slowly add water to all the time turning it with the shovel. 
If you must do it in the barrow, the old plasterers used to use a thing like a hoe, with a hole in it, and that made it a lot easier that a shovel. I have used a mattock for the same, but only for the odd barrow or two. 
A sand bed sounds awfully temping eh? 
cheers 
Bill

----------


## journeyman Mick

> .........A sand bed sounds awfully temping eh?...........

  And it's actually the preferred base for a water tank. 
Mick

----------


## zongatron

Top response guys. Thanks for the input.
Re the sand bed, the tank is a bluescope tank which is basically sheets of moulded tin riveted/screwed together and then about 30 tubes of silicon to seal the gaps. I know it aint the best but its more than half the price of concrete, full plastic and even the better grade steel tanks which have bladders that can be replaced. All the above come in at round $4500 for 20 000 litres while the bluscope is $2000 for 17400 litres. 
I have two concrete tanks for house and this third is for the vegies + outdoor bath so... Also it has 20 year warranty the same as plastic tanks and the better steel ones.
I spoke to the bloke who builds them and he said concrete slab or timber base. he wont warranty it against anything else because any moovement at all and the silicon comes under stress etc and sand might settle too far or shift and he also said that when you are trying to place it it is difficult to put the tank in place without walking over the sand bed making holes etc...
I wanted a blue metal base boxed in but he said no to that too. 
Thanks again. Bloody quick too to get help here isnt it  :2thumbsup:

----------


## Bleedin Thumb

> Unless of course Bob's got hungry boards on his barrow.

  He must also have muscles in places I don't. :Biggrin:   I usually go 8 barrows per cube out of a premixed truck but if your mixing it yourself it would be easily 11.  I wouldn't even think about it without a mixer.. because mixing up in a barrow is about as thrilling as digging holes by hand in clay. :Tongue:

----------


## zongatron

Also guys - while on topic.
How clean does my metal have to be?
I have almost enough laying out on my driveway which  i need to shift as im putting a slab there one day. Its very clayey, loads of small sticks and small loose bark. Will that be fine to shovel up and use? Or should i go some fresh stuff?
And what qulity sand? Good sharp brickies sand or as its only a water tank base can i use some au natural grainy river sand off the side of the road and maybe giving it a light sift.
Im sure your getting my modus operandi here. Dont mind the labour mixing in a barrow. Dont mind the labour loading up the trailer with sand, dont mind the labour scraping up about a metre of mertal. 
bear in mind i live aways outta town and its far easier to drive down the road and load up the trailer than it is to drive into town and get them to dump a load onto my trailer.

----------


## Terrian

> We used to work on one cubic yard being 27 cubic feet and 3 cubic feet to a wheelbarrow, that's 9 wheelbarrows to a yard., Say 11 for a cubic M.  Unless of course Bob's got hungry boards on his barrow. Concrete weighs about 2.4 tonne per cu M. Work it out.

  
always worked it to be about 12 barrows to the m3, more than 1/2 a barrow load of  concrete is too much for me to be moving too far these days  :Redface: )

----------


## Terrian

> He must also have muscles in places I don't.  I usually go 8 barrows per cube out of a premixed truck but if your mixing it yourself it would be easily 11.  I wouldn't even think about it without a mixer.. because mixing up in a barrow is about as thrilling as digging holes by hand in clay.

  next time I need to dig a hole in clay then fill it with concrete I will remember to get you over here, I'll dig the clay  :Redface: )

----------


## Terrian

> And it's actually the preferred base for a water tank. 
> Mick

  yep, as the tank fills it makes an impression in the sand, that helps the whole bottom to support the weight.
(edit, seeing as how it is a metal tank, I would use a timber base with a small gap between the boards, like decking, rather than concrete or sand base)

----------


## speedy

I've mixed concrete in a barrow and it's hard work, i'm not sure where you live but I would forget the barrow and hire a cement mixer. The hire charge wouldn't be that much and you would only need it for one day and your back will be most greatful. :2thumbsup:

----------


## Bleedin Thumb

> next time I need to dig a hole in clay then fill it with concrete I will remember to get you over here, I'll dig the clay )

  
Not sure where Kilsyth is but I think the float on the excavator might prove to be a bit prohibitive. :Biggrin:

----------


## mick101

I just finished mine today...2000mm x 2000mm & 340mm at one end & 120mm at the other. Sloping block & its a long story as to why i couldnt dig it level. 
I ordered 1 x MT3 & it took a cats whisker under that (one shovel full under actually) ..anyway i asked the driver how many builders barrows in a MT3 & he said about 15. 
I had considered doing it myself but after that no way in hell would i have done it myself.

----------


## atregent

I only needed 0.8m3 for my shed base, and getting it pre-mixed and delivered was one of the best decisions I've made.  
The bloke turned up at 8am, poured it all into the formwork (I was lucky that he could back the truck right up to where I wanted it poured), and I was kicking back with a coffee by quarter to nine, admiring my new slab. 
I got mine from Boral, the guy I dealt with when I was ordering it was very helpful. I had no idea there was so many variables with concrete. 
I reckon if I did it by hand, I would have still been going by tea time.

----------


## echnidna

theres 35 cubic feet in a cubic metre so the truck driver must be used to using ladies garden barrows.

----------


## Bleedin Thumb

You always have to order extra, I usually order 0.2 cu.m extra _minumum._ 
I'm with you re the ladies barrows Bob. If you leave it to the truck driver to fill the barrows you get about 6 per cu.m ...but don't make waves. :Shock:   
For every nice helpfull driver out there there seems to be one that wants to make your pour as difficult and rushed as possible. These are usually the same ones that result in the big time penalties. :Annoyed:

----------


## manoftalent

Mate....why kill yaself doing it the hard way ??.....to hire a cement mixer only cost me $30 for the weekend ....there must be places like that around you, I think even bunnies hire em out ...pour it all in one, and mixed correctly first time .......save ya a lot of headaches mate .. :2thumbsup:

----------


## Terrian

> Not sure where Kilsyth is but I think the float on the excavator might prove to be a bit prohibitive.

  outer eastern suburbs of melbourne, maybe I should just get the 20tonner cat from work then   :Smilie:

----------


## Terrian

> theres 35 cubic feet in a cubic metre so the truck driver must be used to using ladies garden barrows.

  wheeling 1/2 barrows (builders barrow) of 70 slump concrete over rough ground is my limit  :Smilie:

----------


## Terrian

> You always have to order extra, I usually order 0.2 cu.m extra _minumum._ 
> I'm with you re the ladies barrows Bob. If you leave it to the truck driver to fill the barrows you get about 6 per cu.m ...but don't make waves.  
> For every nice helpfull driver out there there seems to be one that wants to make your pour as difficult and rushed as possible. These are usually the same ones that result in the big time penalties.

  there is normally about a 20 minute limit onsite for mini mix, after that there is extra costs. 
3 of us on barrows took about 25 minutes to empty a maxi with 5.5m3. 
I always try (tried) to get the truck right to the job (85 - 90 slump, easier to screed  :Smilie:   )

----------


## mick101

> You always have to order extra, I usually order 0.2 cu.m extra _minumum._ 
> I'm with you re the ladies barrows Bob. If you leave it to the truck driver to fill the barrows you get about 6 per cu.m ...but don't make waves.  
> For every nice helpfull driver out there there seems to be one that wants to make your pour as difficult and rushed as possible. These are usually the same ones that result in the big time penalties.

  Yeah i got a good driver which really helped for someone like me whom has never laid a slab before. He got in & showed me how to work it into everywhere & not get air pockets. I had some wobbly ground so he spared me with smaller barrow loads. Man the stuff is heavy for its quantity !!

----------


## zongatron

Just in petrol it would cost me about $50 to go and pick up a mixer. I think ill just mix it up on some ply and shovel it into the barrow. I still have to wheel it about 30 meters uphill no matter what as the ground is too uneven to mix by the formwork. Even if i got a delivery i would have to barrow it all up the hill..It is a possibility one of the nearby farms has a mixer. Might drop in on them...
thanks boys

----------


## catbuilder

Ask one of the farmers if they've got a PTO mixer for their tractor, 1) you'll mix a larger batch at a time, 2) you can reverse the tractor up the hill to your formwork, 3) it would probably cost a slab. 
We've done silo bases here in no time.  Also done a dairy yard extension a few years ago, a lot of concrete all mixed on site in a day. 
Only way to go, not every farmer has one, but theres bound to one that does. 
Regards 
Matt

----------


## ian

> Re the sand bed, the tank is a bluescope tank which is basically sheets of moulded tin riveted/screwed together and then about 30 tubes of silicon to seal the gaps. I know it aint the best but its more than half the price of concrete, full plastic and even the better grade steel tanks which have bladders that can be replaced. All the above come in at round $4500 for 20 000 litres while the bluscope is $2000 for 17400 litres.  
> I have two concrete tanks for house and this third is for the vegies + outdoor bath so... Also it has 20 year warranty the same as plastic tanks and the better steel ones. 
> I spoke to the bloke who builds them and he said concrete slab or timber base. he wont warranty it against anything else because any moovement at all and the silicon comes under stress etc and sand might settle too far or shift and he also said that when you are trying to place it it is difficult to put the tank in place without walking over the sand bed making holes etc... 
> I wanted a blue metal base boxed in but he said no to that too.

   

> Also guys - How clean does my metal have to be? 
> I have almost enough laying out on my driveway which i need to shift as im putting a slab there one day. Its very clayey, loads of small sticks and small loose bark. Will that be fine to shovel up and use? Or should i go some fresh stuff? 
> And what qulity sand? Good sharp brickies sand or as its only a water tank base can i use some au natural grainy river sand off the side of the road and maybe giving it a light sift. 
> Im sure your getting my modus operandi here. Dont mind the labour mixing in a barrow. Dont mind the labour loading up the trailer with sand, dont mind the labour scraping up about a metre of mertal.  
> bear in mind i live aways outta town and its far easier to drive down the road and load up the trailer than it is to drive into town and get them to dump a load onto my trailer.

   

> Just in petrol it would cost me about $50 to go and pick up a mixer. I think ill just mix it up on some ply and shovel it into the barrow. I still have to wheel it about 30 meters uphill no matter what as the ground is too uneven to mix by the formwork. Even if i got a delivery i would have to barrow it all up the hill..It is a possibility one of the nearby farms has a mixer. Might drop in on them...

  As you can see I've gone back over this thread. 
from your info I'd strongly advise you to forget the concrete and go with a substantial timber or steel base. 
Based on what you have said, your tank supplier is recommending a 20MPa or concrete slab.  You will not achieve anything like this strength using found (dirty) gravel and sand, especially if you're mixing it in a barrow and pouring it in very small blobs on very uneven ground.   
The likely outcome is several largely independent lumps of concrete that over time will move leading to failure of your tank.  
ian

----------

