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Things to know about building a segmental retaining wall

image of several tiers in a segmented retaining wallSegmental retaining walls have been steadily growing in popularity for a wide range of residential and commercial uses as the variety and quality of building materials has improved over the years.

Their popularity is due in large part to the fact that segmental retaining walls are less expensive than poured-in-place concrete walls and more durable than timber retaining walls. The systems are also easy to install and they don’t require mortar or concrete footings.

If you’re new to masonry products and construction, you may be asking “what is a segmental retaining wall?” Segmental retaining walls consist of modular concrete blocks that interlock with each other. They’re used to hold back a sloping face of soil to provide a solid, vertical front. Without adequate retention, slopes can cave, slump or slide. With the unique construction of segmental retaining walls, higher and steeper walls can be constructed with the ability to retain the force of lateral earth pressure created by the backfill soil.

Segmental retaining walls can be installed in a wide variety of colors, sizes, and textures. They can incorporate straight or curved lines, steps, and corners. They’re ideal for not only slope support, but also for widening areas that would otherwise be unusable due to the natural slope of the land. Retaining walls are often used for grade changes, and for other functional reasons such as widening driveways, walkways, or creating more space in a recreational outdoor area.

Of course, soil composition is a critical factor in how and where a segmental retaining wall can be built. The soil should drain well so that it will not hold water. Water tends to be the one thing that will cause problems and negatively affect the structure. For example, there may be a water source getting in behind the wall that may loosen up the compacted base, causing settling and shifting. Once winter sets in, if the water is still present behind the wall it will freeze and expand, causing the wall to buckle and shift over the course of a couple years.

Once you’ve determined that you have the right soil and topography to successfully install a segmental retaining wall, it’s important to do the appropriate prep work prior to starting construction.

The National Concrete Masonry Association recommends that you do the following:

  • Contact local utility services to identify location of underground pipelines, conduits and utility lines.
  • Check with local building officials or residential inspection services to determine any requirements for construction certificates or inspections needed. This is often a requirement when retaining walls exceed four feet.
  • Coordinate delivery and storage of materials to ensure unobstructed access to the work area and materials.
  • Review the supplier’s recommended installation and structural requirements.

If you know your environment and do your homework up front before you start your retaining wall project, it’ll help ensure that you’ll have an attractive, functional, and reliable segmental retaining wall that will provide years of service.