Filling a trench with concrete

[trevorbayliss]

Any ideas on length of time it will take to fill foundations which will probably need 10 cub meters of concrete.

The mixer truck would be positioned at the bottom of a small drive. So 15m run up the flattish drive round the back.

Need to fill 21m of trench.

The truck stops for 30mins and then after that charges. If i am doing this on my own i know it will take ages. So any idea on time frame for this ?

I am toying with the idea of making my own concrete as it will be easier for me if i am on own.

 

[tomfe]

WTF you're going to move 10 m3 of concrete on your own?
24tonnes!
You're having a laugh.

10m3 for 21m of trench seems quite a lot are you sure that's right?

 

[Morpheus Cane]

according to a website it says there are 25 builders wheel barrows full to move 1.0 metres of concrete times that by 10 going to take you a while if you don't collapse with exhaustion first

 

[stuart45]

How deep is your trench?

 

[trevorbayliss]

Well i have it as 21m x 800mm deep x 600mm width. So 10 cubic meters, which i thought was 20T

Your right 20 T is too much for 1 and probably too much for 2 peeps.

Which is why i was thinking about using 20T ballast and move it round the back and then start making the concrete slowly.

 

[Morpheus Cane]

if there is enough access you could hire a mini dumper truck and use that

 

[trevorbayliss]

That trench depth probably doesn't need to be all concrete though. I will need to see what BC say about how deep i dig down and the actual footing thickness.

So i think it maybe nearer 5 cubic meters

 

[trevorbayliss]

yes access is no issue really. Not for a small one.

 

[Ian H]

You need the truck (or 4 trucks) to get near enough so you can pour it in directly. Will it not fit up the driveway?

Ours was about 6mtrs away so I made a Shute out of timber and lined it with visqueen. It was hard enough tamping it with a rake once it was in the trench and that was only 6cubic mtrs over 12mtrs of trench.

To mix it yourself would take about 30 bulk bags if ballast? I think you need a pumped concrete service.

 

[trevorbayliss]

This is my worry about speed of the concrete going off.

The truck won't be able to get that close.

I do think i will need much less concrete now i have thought about it. The less i need means i will seriously be looking at mixing myself with a mixer.

If it is 5cubm, then that is 10 T ballast i think plus the cement. I think that is doable as i can shift the ballast from the drive to the back next to the foundation area and then mix the next day.

 

[stuart45]

You don't have to trench fill. It's normally done like that nowadays to save labour with the bricklayers working in the trench, but you can use less concrete and build up the footing yourself in blockwork.

 

[trevorbayliss]

Well i am the one doing all the work pretty much so any saving is my own.

If my trench is 800mm deep and the foundation is for a single storey ext, what is the likely depth of the concrete needed ? BC will advise when i get all the planning i am sure.

 

[stuart45]

Years ago 9 inches of concrete was standard for the footings.

 

[JohnD]

can you get a concrete pump? Saves a lot of work when access is difficult and labour is short.

 

[Morpheus Cane]

Depth depends on soil type, trees near by and stuff. Mine had to be 1.7 meters deep and 600mm wide as we are clay and had a tree close by