Key takeaways
- Drainage behind the wall is the most important detail.
- Footings need to be below frost depth and well compacted.
- Tall walls usually need engineering or a permit.
- Tiered walls are stronger than a single tall wall.
Why walls fail
Soil behind a wall gets very heavy when it is wet. If water cannot leave through drainage stone and a pipe, pressure builds and pushes the wall over. Tennessee's clay holds water, which makes drainage especially important.
The other common causes are shallow or uncompacted bases, walls built too tall for their design and missing reinforcement.
What a good wall includes
A buried base course on compacted stone, drainage stone behind the wall, a perforated pipe that carries water out, reinforcement such as geogrid for taller walls and a cap that sheds water. Natural stone, block and brick can all work if these pieces are in place.
For tall walls, we recommend tiers with space between them, which breaks the load into smaller steps.
Permits and planning
Many cities require permits or engineering for walls over about four feet, or walls that support driveways or buildings. We check the rules, work with engineers when needed and plan access for equipment before we start.
Related services
Quick answers
How long does a retaining wall last?
A well-built wall with good drainage can last fifty years or more. Neglected drainage is the most common reason walls fail early.
Can I build a retaining wall myself?
Low garden walls are possible for a careful homeowner. Anything holding back significant soil should be built or designed by a pro.
Ready to talk it through? Get a free estimate or call 615-431-3789.