Treated timber is approved for in ground use and has a reasonable service life, however block retaining walls and concrete sleeper retaining walls are more durable having a greater life expectancy. This is based on suitable footings & good drainage. Both Blocks and concrete sleepers come in a wide range of colours, sizes and styles to create a more aesthetic landscape. Common styles of retainers walls to consider are timber sleep retaining walls, link wall or link block retaining walls and concrete sleeper walls