Concrete shed base

5500

Hi Guys
I've ordered a 3x3 meter steel shed and in need of a base. The seller said I've 3 options, lay on blocks over grass that's there, lay on 804 and fill the inside, or build a slab to leave asmall overhang without having to infill

The seller supplied a contractor number and they are looking for 1k to do a 4inch slab, that's over half the cost of the shed and at that id like to give it a go myself, but I'm just looking for some pointers.

A calculator works it out at just under a cubic meter and calls for

13 bag(s) of cement
720 kg of sand
1080 kg of aggregate

For starters I can get a loan of a mixer, but should I just be looking at getting a pour of 1cube concrete and barrowing in?

Or pour aside, am I right as follows,
dig out topsoil to 6inch depth
Make 4x2 frame of base,
Fill in with 804 stone compacted level to 2inch
Lay damp proof layer
Mix and pour concrete - do I have any other option here than 1T bag sand,1T bag of aggregate eg this https://tjomahony.ie/178008-1.html, and if so what does the mix ratio work out at then with cement and water

Any pointers greatly appreciated!

Explosive_Cornflake

1k seems an okay quote, maybe a bit cheap even?

Who's getting rid on the topsoil?

What's going in the shed? Would you insulate the slab?

5500

I'd to get rid of topsoil myself, price was the slab only, it's purely for garden bits and bobs/tools so wasn't going to go down the insulation road

finbarrk

I did one of those. A 3 inch depth of concrete is plenty. We had readymix coming in for another job so we didn't have to mix it ourselves.

Fine Cheers

Price the ready mix and that might make up your mind. You might get stung for an additional charge. Having done exact same job a few weeks ago, its the ready mix option for me but I was piggy backing a friend pouring paths up the road. 2 lads barrowed it in and all done in 45 mins. 100mm slab on dpm. Good solid ground underneath and actually sat on part foundations of adjoining boundary wall. No 804, steel or insulation. I did the digging out and formwork. I was waiting a while and did contemplate borrowing a mixer but thankfully my mate came up trumps. The feedback here to similar posts was to avoid diy mixing if at all possible.

hesker

Try to find a supplier with a small readymix truck. I paid about €250 for a 2.5T delivery a few years back when I needed 2.2T

Even paying €300 when you only need 1T is well worth it when you consider the price you’ll pay for materials and mixer hire and then labour

5500

Thanks guys, will price 1cube tomorrow and see how it fairs off

vicwatson

5500 wrote: »

Thanks guys, will price 1cube tomorrow and see how it fairs off

Don’t use 804, no need, a pain to shift if you are barrowing it in, go for 1” down, same job for this job and much easier to work with

5500

Got a price of 220 for the cube delivered so looks to be the way to go rather than mixing by hand. I got started digging some of it yesterday and it's tough enough ground, I'm half wondering if I'd get away without the sub-base or to just keep at it and do it right so to speak

Fine Cheers

I was happy to poor 100mm+ concrete slab on dpm on existing subsoil. No 804 used. My area was smallish 3m x 2m and I ensured ground was well compacted with sledge and no soft spots. Mesh probably overkill but might give you peace of mind. I didn't use mesh.

5500

vicwatson wrote: »

Don’t use 804, no need, a pain to shift if you are barrowing it in, go for 1” down, same job for this job and much easier to work with

Just to bump this, I was ordering stone to get the subbase done this weekend and when I rang a providers and asked for 1 Inch down he was referring to it as drainage pebble or bandon stone 25mm and less. I told him what it was being used for and he said get 804

So as I'm on the same page is 1inch down the same as the 25mm drainage/bandon stone or do I need to ring a different builders providers?

garv123

the pebble stone wont compact, it can be used for drainage because the water flows in the gaps

804 is about 3" down to dust limestone, and it all compacts well.

you could get 1 inch down which is 1" lime stone.

I never found any issues shovelling 804.