Retaining Walls

Segmental Block Walls in St. Louis, MO

Most of the newer walls around St. Louis are segmental block. You see them in every subdivision in St. Charles and west St. Louis County. The block itself rarely fails. When one of those walls goes wrong, the cause is almost always something behind or under it: a thin base, geogrid that's too short, or backfill of the native silt instead of clean stone. Built properly, block handles the small seasonal movement of clay and settles in with the ground.

Why Block Is the Default

Drive through any subdivision built in St. Charles or west St. Louis County since the 1990s and you'll see segmental block. The units are made in a plant, so each course is the same size, and each one sets back slightly from the one below. Because the courses are dry-stacked rather than mortared, a block wall can take the small seasonal movement of loess and clay without cracking the way a rigid wall would.

That doesn't mean it won't fail. It means that when a block wall fails, the cause is almost never the block itself.

What Makes a Block Wall Last

What we see in failed block walls around here: a leveling pad of a couple of inches of sand instead of compacted crushed stone, geogrid too short for the height, backfill of the native silt instead of clean stone, and a drain pipe that was capped or buried at the end so it never actually drained. We build ours with a compacted stone pad set below grade, geogrid layers at the spacing and length the height calls for, clean stone behind every course, fabric against the soil and an outlet you can see.

If an existing block wall is moving, we can usually reset it using the same block. For taller or heavily loaded walls we look at a full engineered build.

Where Block Makes Sense

Block covers most back-yard terraces in Ballwin, Chesterfield and O'Fallon, replaces timber walls in Oakville, and handles out-of-sight walls on wooded lots in Wildwood and Arnold.

Typical timeline Several days for a typical residential run, including base work and backfill.

Related Services

Work that usually goes with this one on a St. Louis job:

Free, No Obligation

Request a Free Wall Estimate

Tell us what the wall is doing and where it is. A side-on photo helps us figure out the problem before we arrive.

  • Free site visit, no obligation
  • Written scope and price before work starts
  • Drainage priced with the wall, not added later
  • A straight answer if a repair will do

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(557) 256-7261