What's the weight of 0.62m³ of 10mm ballast?

[DaveFix]

I'm having a go at PIC concrete garden paths and patio. I've measured the areas and calculated the total volume as being 0.611m³ (cubic meters).

I went to the builder's yard and asked for a quote for 10 bags of cement and a 0.62m³ (rounded up for margin of error) bag of 10mm ballast. Unfortunately they were unable to quote for the ballast unless I somehow guessed the weight!

According to the interweb I need to know the density of the 10mm ballast to work this out, and no idea how wet their ballast is.

Any suggestions?

 

[DaveFix]

According to noseall's post here:

Cement: Ballast by volume of weight?

hi there, When pouring my footings I ran out 2/3 of the way through. Something was up with my calcultations. Footings 600x 200x3500 (3.5x0.6x0.2) which I worked out was 0.42 m3 I think my mistake came when I assumed a cubic metere bag was just that and thatit weighed a tonne. (I...

www.diynot.com

1.9 tonnes of ballast (+ cement and water) will make 1m³ of concrete.

(I'm not sure his calculations to take account of the weight of the water?)

Since I need 0.62m³ which is about 38% less than 1m³, I assume this means I need 1.16 tonnes of 10mm ballast.

Does that sound right?

 

[Alec_t]

Does that sound right?

Yes. Google says about 1.8 tonnes/cu m, which works out at 1.12 tonnes for 0.62 cu m.

 

[DaveFix]

Went back to the builder's yard thinking I could get it all sorted today, but they threw a spanner in the works and said they don't do 10mm ballast.

I'm not that experienced with concrete.

Not sure if 20mm ballast would give as good a finish with PIC as 10mm would.

Also I would have to bring this all through the house bucket by bucket, and I've found 10mm is very easy to scoop, 20mm much more hard work.

They said I could buy 10mm gravel in 25kg bags and a 1 tonne bag of sharp sand but mix them myself, and I would need to work out the ratio and tell them how much I want.

Ideally I would have everything in 25kg bags (sand, cement, 10mm gravel) and it would be easier and far quicker to carry through the house.

However, having things in 25kg bags would of course be far more expensive. (For example, they quoted £38+VAT for a 1 tonne bag of 20mm ballast, but if supplied in 25kg bags then it would cost £132.40+VAT).

I'm not sure what to do.

Starting to think I just have to accept buying 20mm ballast in a 1 tonne bag, plus buy an empty bag for the back garden and spend a few days moving it through the house.

 

[lostinthelight]

20mm is as easy to shovel as 10mm if you slit the bag and let it fall onto hard smooth standing or even a sheet of board. 1.8 tonne m³ is equivalent to 1.8kgs per ltr

 

[Charlie George]

Went back to the builder's yard thinking I could get it all sorted today, but they threw a spanner in the works and said they don't do 10mm ballast.

I'm not that experienced with concrete.

Not sure if 20mm ballast would give as good a finish with PIC as 10mm would.

Also I would have to bring this all through the house bucket by bucket, and I've found 10mm is very easy to scoop, 20mm much more hard work.

They said I could buy 10mm gravel in 25kg bags and a 1 tonne bag of sharp sand but mix them myself, and I would need to work out the ratio and tell them how much I want.

Ideally I would have everything in 25kg bags (sand, cement, 10mm gravel) and it would be easier and far quicker to carry through the house.

However, having things in 25kg bags would of course be far more expensive. (For example, they quoted £38+VAT for a 1 tonne bag of 20mm ballast, but if supplied in 25kg bags then it would cost £132.40+VAT).

I'm not sure what to do.

Starting to think I just have to accept buying 20mm ballast in a 1 tonne bag, plus buy an empty bag for the back garden and spend a few days moving it through the house.

Check with them regarding the bags, most merchants sell in bulk bags which weigh around 800kg, but still commonly called tonne bags, you may need to top up with 25kg bags.

 

[DaveFix]

20mm is as easy to shovel as 10mm if you slit the bag and let it fall onto hard smooth standing or even a sheet of board. 1.8 tonne m³ is equivalent to 1.8kgs per ltr

Good point about using the board.

Anyway, I've been shovelling the new ballast delivery and it's not very difficult getting the spade in at all. My previous bad experience was with a bag that had stood for several years, so I think it was only difficult because it had become compacted.