Concrete Fill? how much

[mrbg07546]

Hi,

I am going to dig and fill a trench for a new porch. following this i need to fill with concrete.

After this i will let the bricky do his thing.

I have access to a cement mixer should i need.

The footing will be 1 meter deep(as advised by architect) and 600mm wide.

Now how much concrete should i put in. I know it has to be minimun 200mmish. Should i just fill it quite high up? around 90cm?

should i fill it a bit less and have 1 course of engineering block?

should i just fill it about 300 and thats it?

what are your thoughtss

In addition per m3 cube how much jumbo bags of balast(850kg) and normal size bags of cement should i use?

Cost is a important factor here for me.

 

[theprinceofdarkness]

I would fill it 300mm then use foundation blocks to just under ground level. Work out the length of your trench then multiply it by 300mm, this will give you the volume. As I have said before 850 Kg is great for a counterweight, you need its volume, I think its about .7 cu m.
Frank

 

[stuart45]

You need to know what your DPC level is and then work down from that. If you are having face brickwork, make sure it will work out in brick courses from the top of the blockwork.

 

[noseall]

A couple of block courses (450mm) down from DPC will afford you enough room to fit a bottle gully should you need to.
You can set the concrete as high as you dare as long as there are no interferences and ground levels do not differ significantly across the site. The highest we have set the foundation level (also for a porch) is 300mm down from DPC. You will need to show engineering brick above ground level. Three courses is usually enough.