Retaining wall

longwalks1

I need to build a retaining wall approx 10m in length, by about 45cm high to support one edge of a patio area.  It will be rendered after its built.  What blocks will I need, and will it need to be double thickness?  It’s to hold the type 1 base in preparation for the patio

thank you in advance 

grumbler

I am no expert, but even a usual 10m wall, not retaining, I would build double and with extra intermediate supports.

longwalks1

Thanks grumbler, how would you add the intermediate supports? 

TELLIT01

A possible alternative, to avoid the need for intermediate supports, would be hollow concrete blocks with vertical reinforcing rods and filled with concrete.

grumbler

britishboy said:

 how would you add the intermediate supports? 

At least several perpendicular 'ribs', reliably linked to the main wall and going about 0.5m into/inside the patio. I am sure you'll find more professional ways if you search.

tonyh66

and don't forget the drainage to release water from behind the wall, oh and make sure the foundations are good and adequate.

stuart45

Use dense concrete blocks if going for solid blocks. Double bond them if laying them flat. 
Render isn't ideal for a retaining wall. Another issue with that length in blockwork is shrinkage cracking.