How to POUR concrete footings

[moconnell]

I have a garden room that I am about to build that is on a minor slope. I want a small brick wall to about knee height on to which I will put a wooden structure. I have a square of 4 Trenchs 18 inch wide each approx 5 m long. I want to have a have good enough foundations and have been advised a foot deep concrete foundations should be good enough. My plot is at the end of a 100ft garden my question is what concrete approach should I take? I have a 120l concrete mixer. Could I do this in sections using this? Or should I pay for 'readymix' given I will have to Wheel barrow it down the garden 100ft+ each time?

 

[23vc]

What thickness of concrete? Highly likely you can use your mixer

 

[noseall]

what concrete approach should I take?

Readymix and pump it.

 

[moconnell]

What thickness of concrete? Highly likely you can use your mixer

Foot deep at the lowest just to keep costs down but want it to be stable..

 

[moconnell]

Readymix and pump it.

Not sure if they can pump 50+ m but I guess I can ask..

 

[noseall]

Not sure if they can pump 50+ m but I guess I can ask..

Lol. They've probably got enough hose to go around your house three times. Just tell them the distance. The trick is with a distant pour is calculating how much is left in the hopper and hoses so that you don't end up with too much.

 

[^woody^]

225mm concrete will do. It needs to be done as one pour.

Use one of those firms that mix it on site and a chap barrows it.

 

[dontbelieveawordofit]

readymix.

 

[Scarlet Pimpernel]

.. The trick is with a distant pour is calculating how much is left in the hopper and hoses so that you don't end up with too much.

Don't they clean the hose of remaining concrete at the end?
The trick is not stand in front of the hose when the ball comes out.

 

[noseall]

Don't they clean the hose of remaining concrete at the end?

Yes the conc gets pushed out with the foam ball and splatters everything within 50 yards. Its more about knowing when to ask the mixer guy when to stop feeding it into the pump hopper.

 

[moconnell]

I'm coming back to this as Ive tried to find local wheel barrow readymix but can't get anyone to do it (70 m trip from road) so I'm going to attempt to do this with my 120litre mixer. I am thinking about doing it in sections on lenth at a time (just going to wack some hard board in to block off the trenches to do it in batches).Hopefully this is doable, or should I try to do it in one pour? How bad is it to have a 5 mm gap between foundations pours or butting up to an older pour?

 

[mikeey84]

I'm pretty sure that won't work, as I understand you need the foundation to be one single bit, not a few separate parts.

I'm sure with some rebar you could make it work, but as said, you only need 225mm deep- have you worked out the volume needed? How many mixes in your mixer is it?

 

[moconnell]

Its about 1.8M3, I'm expecting my 120litre mixer can only really mix half its capacity at a time (I'm guessing I've never done this before) so dividing by .06 says 30 loads.
If it takes 5 mins a load shovelling in 7 shovels worth mixing and adding water, then decant in to wheelbarrow and then pour I'd give a conservative 5 mins each - which is 2.5hours. I think the concrete will start to go off before I'm done, but I'm not sure?

 

[mikeey84]

I'm not sure either to be honest, but I reckon that would be a better option than doing them separately

 

[moconnell]

I'm guess I'll do it in one then - I mean I only have to have 15cm deep really and I recokon I can mix 20 easily in the cut off point so if it starts hardening before I get to 225 mm - well its only a gloriified shed!