Concrete blocks in concrete mix

[MrDaveyBoy]

I'm about to build a small retaining wall 2 concrete blocks high 17" (430mm) that will have a patio going on top. My question is, can I bed the concrete blocks straight into the concrete foundation rather than using a layer of mortar? Also, I'm planning on having the foundation 4" (100mm) deep and 12" (300mm) wide - is this enough? TIA

 

[JerryM]

u could bed the blocks straight in the concrete - it's not normal practise - the mortar allows u to get the positioning right (line & level).

the foundation at 100 deep x 300 wide is fine. if anything i would go 6" on the foundation but only if u think it needs it.

 

[chessspy]

Hi, Davey boy,
It's kind of sloppy bad practice, and why not do it properly in the first place.
If a jobs worth doing badly, then it's worth doing well too.

 

[MrDaveyBoy]

Thank you for your replies, I have laid the foundations minus concrete blocks and will use mortar as is the norm.

Dave

 

[JerryM]

make sure u use a piece of string or line to keep them in line and level.

the line needs to be over the full length and taught/held (by bricks at each end) just above the coarse being laid.