Concrete amount??

[Greenie9657]

good evening all,

I know this is a proper basic question but I can't seem to find a decent calculator online. Im quite handy with most job but I have never messed with concrete so looking for some help. I have an 8ft x 10ft shed which I want to make a concrete floor for. I'm happy building the timber frame (although unsure what is the best wood) to pour the concrete in but how much do I need to order of rough sand, cement and aggregate? I'll probably do the frame 10x12.(1 foot extra all the way round for the wife to decorate with plants) and around 4 inches deep.

Regards

 

[HERTS P&D]

Is this any good?

http://www.concrete2you.com/Concrete-Calculator/

Andy

 

[Greenie9657]

Good morning Andy,

It came up at 1.13m3, doesn't sound a lot. What do you think? Also it doesn't say how big of a bag indeed of each.

Sorry for the questions but like I said, I'm completely new to laying concrete!!

Regards

 

[noseall]

You will need two tonne bags of ballast and 13 x 25kg bags of cement for a 100mm thick base of that size.

 

[Greenie9657]

Noseall,

That's great, thanks. But....what's ballast? Lol Is that sand and aggregate mixed?

What mixing ratio do you recommend? I was thinking 4 to 1 but once again, not really sure.

 

[WabbitPoo]

Google is a marvellous tool.........http://source4me.co.uk/calculate_concrete_mix.php

 

[Greenie9657]

Google is a marvellous tool.........http://source4me.co.uk/calculate_concrete_mix.php

I do sometimes use google for ideas but I'd rather speak to someone who has experience in doing it for advise.

Great website though.

 

[Footsoldier888]

Is 4 inches deemed to be the standard for a timber shed base of the OP's size?

Is it a good idea to add reinforcement mesh atall???

On Amazing Spaces I saw a guy place his posts in buckets of cement instead of a slab, the buckets being in the ground. I think he used six in all. Thought it was a clever solution, anyone done that???

 

[Greenie9657]

Foot,

Is that bucket thing on the Internet to have a look at? I was just in the garden planning the frame work to pour into. I'm open for any other ideas.

 

[noseall]

Mix it 6:1. Standard mix. Ballast is sand and gravel mixed.

 

[Footsoldier888]

Foot,

Is that bucket thing on the Internet to have a look at? I was just in the garden planning the frame work to pour into. I'm open for any other ideas.

http://www.channel4.com/programmes/george-clarkes-amazing-spaces/on-demand/60244-001

I think it was on this one, the summary is a bit brief. It was an outbuilding a chap built for his gran and had model boats in. The guy was a newly qualified architect.

 

[Greenie9657]

Do I use this with just cement? 6:1 ratio. Do I need pva or plastasiser like when you build a wall?

 

[noseall]

No need for any plasticiser or admixture. All you need is water.

 

[Greenie9657]

Is the 20mm ballast ok?

 

[noseall]

Is the 20mm ballast ok?

Yes, perfect.