Wall thickness

We are having a short section of wall built in solid concrete blocks to act as a sound screen around a garden seating area. It is L shaped in plan with lengths of 3.5m and 5m and a height of 2m (9 courses). If we have pillars half way along each section can the wall be a single thickness of 100mm or must it be two blocks thick? It will carry no load other than supporting the ends of some pergola cross pieces.

It will be OK. But you should have a pier at the ends too

Make sure the foundations are adequate to give it a stable base.

OK Thanks woody.