Calculating how much cement

[olaf]

Afternoon all,

As I have said in some other threads I'm going to be building myself a new shed. Part of this is obviously laying a floor. The current plan is for brick on foundations round the edges which the wall will sit on, then a hardcore subsurface and concrete base for the shed, with a 'false' wooden floor, and insulation on top of it.

I need to work out a cost for getting this built, and using the useful info page I can get the mixture ratio for the concrete, but can't find any detail on how much volume a bag will fill....

All help appreciated

 

[noseall]

can't find any detail on how much volume a bag will fill....

Hand bag?

Shopping bag?

Rubble bag?

Tonne bag?

Sports bag?

Old bag?

No wonder you found it difficult.....

If you mean a trade tonne bag then this will do roughly half a cubic metre and would require about 6 or 7 x 25kg bags of cement (and water) mixed with it to produce concrete

 

[olaf]

Thanks. I think.

Never seen a handbag full onf concrete, but SWMBO's weighs enough so I could be wrong.

To add to my Query then:

In a mix for foundations what volume will a 25kg bag of cement mixed to form concrete fill?

In a mix for flooring use what volume will a 25kg bag of cement mixed to form concrete fill?

Think I have covered that. I should be able to work out the amount of ballast/sand etc needed from those answers and the ratios on the how to page.

Thanks.

 

[noseall]

In a mix for foundations what volume will a 25kg bag of cement mixed to form concrete fill?

In a mix for flooring use what volume will a 25kg bag of cement mixed to form concrete fill?

Crazy questions????

Concrete is generally mixed at 6 parts ballast (sand and gravel mixed) to 1 part cement. It can be made weaker or stronger if you wish. It can also be mixed sloppy or semi-dry so the filling capacity changes as does the depth of foundations and floor slab depths.

You would be better off giving a measurement of what needs filling and we will tell you quantities required. I suppose given that a ratio of 6:1 is a typical concrete mix, then a 25 kg bag of dust will produce 0.075m³ volume of concrete.