cement straight onto soil?

[wayki]

hi,

i am building a small 4 inch wall type thing that will be arced - bit like a letter ' n ' - can i put the "quite dry and maliable" cement mix straight onto "hard soil / ground" or do i need gravel , compost etc.

the wall is really to seal-in and hide the edge of a a pool liner at the top of a small outdoor bath / pool. (in spain).

 

[r896neo]

All mortar walls no matter how small need some sort of stable foundation or the small movement will crack the joints.

Even a 4 inch thick strip of concrete would be plenty for your plans

 

[wayki]

All mortar walls no matter how small need some sort of stable foundation or the small movement will crack the joints.

by stable you mean i can place cement onto hard ground (spanish soil), or should i add some gravel / stones onto the hard ground first?

thanks

 

[r896neo]

No sorry if i wasn;t clear, you need a foundation. No matter how hard you think the ground is unless its solid rock its not stable enough.

Use a small concrete foundation as i suggested

 

[wayki]

No sorry if i wasn;t clear, you need a foundation. No matter how hard you think the ground is unless its solid rock its not stable enough.

Use a small concrete foundation as i suggested

forgive me, i am not too good at DIY, but if i use a "concrete foundation," then surely, how is that attached to the ground (hard soil) ? that itself would be cement onto the ground would it not?

 

[r896neo]

Firstly cement is nothing on its own Its merely part of concretes and mortars

You build bricks using mortar which is sand + cement

Concrete is used for a foundation which is sand + Stone + cement.

Mortar is not suitable as a foundation because it is to weak when used in a thickness above 30mm or so.