How deep to make concete foundation for 1000l tank

books4nz, Oct 17, 8:39am
Building concrete base then concrete block structure for two 1000 litre tanks - the tanks with the grill around them. With the weight once they're full, how deep do I need to have the concrete foundation.

They'll be four concrete blocks high, then the tanks on that, reinforcing in the foundation, steel reinforcing vertically inside the blocks, which will be filled with concrete once finished.

Can someone post please with how deep I need to make the foundation concrete?

Thanks for help.
newtec1, Oct 17, 8:50am
It's not always the depth of the footing but the footprint to carry the load.We have put 10000 litres tanks on the ground with no conc and just 100mm of GAP7 metal.how big are the tanks,1000 ltres is not that big.1000 ltres = 1 ton.
books4nz, Oct 17, 8:56am
Hi. thanks for posting. the tanks are 1001mm x 1201mm x 1160mm high. I'll be setting them up side by side, making the length 2402mm.

adding. with the height, 4 concrete blocks high - 4 x 190mm = 760mm plus mortar, plus the height of the tank, making 1920mm high plus mortar.
newtec1, Oct 17, 9:12am
Make the footing wider than the depth.The reinforced block wall 800mm high and solid filled with reo bars will act as a load bearing structure.BTW,when calculating the height of blocks you always calculate them as 200mm including mortar. The footprint is the most important,we used to build block bases for houses on a 50 mm thick conc pad with no reo and rely on the block base as the structure. Not so now as we use a fully reinforced footing built to E/Q standard.400 wx 200d with 2 bars should be ample for your small project.
books4nz, Oct 17, 9:19am
Ok. thanks. sounds like what I've dug out for the base this afternoon will fit what's needed, have made it wider and longer than the concrete blocks need. 100mm deep sound ok? or deeper? - adding - just saw your suggestion of 200mm deep, make it as that?

Thanks for clarifying the 200mm for the block height too.
newtec1, Oct 17, 9:37am
Yep 200mm would be plenty with 2 12mm reo bars side by side.Some vert reo @ 600 centres with a bond beam @ the top with another horozontal bar.Don't forget to use a 90deg bend on the bott of the verts to tie to the footing steel.I hope that's not too complicated,but it's not rocket science,just common sense.
books4nz, Oct 17, 9:40am
Ok. hadn't thought about the horizontal bar. will do that, the rest is sorted. thanks for all your help Newtec.

I'm loving doing DIY things, bought myself a concrete mixer, and have built everything here since it was a bare section. women can do anything huh!

Have a great weekend. :-)
newtec1, Oct 17, 9:52am
Ahhh a woman.If i had known that i would have volunteered.I hope you take that the way it was intended,and yes it can be very satisfying building your own projects.I hope it turns out as planned.My mother always said she wished she could build a house for that reason.She was an apprentice at 14,but not in that trade. Out of curiosity,do you understand what a bond beam is,when you buy your blocks ask for them and they will show you.They are slightly diferent to standard which have the inside web knocked out to run a bar through the middle. Good luck.
books4nz, Oct 17, 10:01am
Hi. :-)
Yes, I have some of those from a previous project to use.

I know how your Mum felt. I designed, got that put into plans, contracted individually with builder, electrician, plumber/drainlayer, etc. myself, and project managed building my home, did all the wall gib, tiling, shelving that's half the height of the wall in my laundry, built kitchen cupboards and shelving, etc. doing all the work. quite a few projects to go outside, 790sqm section can fit quite a few!
newtec1, Oct 17, 10:05am
Crikey,do you want a job.
books4nz, Oct 17, 10:13am
Sure. :-)

I'd love to be building houses/homes for people. I'm 58, if I was young again and starting out I'd be working on something to do with building houses. this is my second build, most of the contractors have worked on both. love seeing it all come to how I picture it in my mind, how I can picture walking through, seeing different aspects of it.

When I bought my concrete mixer, I was chatting with my kids on Skype, the three of us linked. said, guess what I bought. a concrete mixer. That's our Mum, they both said! Then later an email from my son, what are you building now Mum. :-)

Are you a builder? Would be very cool to work in that field.
tintop, Oct 17, 7:22pm
I am not quite clear with what you are attempting.

Will the tanks sit on a slab of some sort surrounded by the block wall, or sitting on a platform that itself is supported by the block work?
newtec1, Oct 17, 8:13pm
Yes a builder,and yes it is a satisfying to see the finished product especially major alteration jobs that need some experience and initiative to change an old dunga into something special. But like everything in life can become monotonous after years of doing the same thing,but good to see a happy client move into a new house or refurbished existing.
tintop, Aug 29, 9:04am
Yes - very satisfying :) I retired early at 60, bought a section and built a large 4 bedroom house to sell. I did it all with the help of my son and a friend when needed, except the bricklaying and the tile roofing, and a sign off for the services from tradies I knew. :)