Multistack segmental retaining wall units where geogrid options are limited

In terms of cost, aesthetics and design flexibility, VERSA-LOK segmental retaining wall units could be your most effective solution the next time you find yourself in a tight spot.

Segmental retaining walls (SRWs) taller than 4 feet typically require soil reinforcement. The most cost-effective way to retain soil in these situations is with a geogrid-reinforced retaining wall—where grid is an option.

But where grid is not an option because of adjacent structures, property line easements, tree roots, or other site conditions, precast big-block walls sometimes are specified. Large precast units can retain soil with a slightly smaller footprint than a grid-reinforced wall, but unfortunately, they also can sacrifice aesthetics, limit design options and increase project costs.

Often, only a small area of a job site is too narrow for grid. Using large precast units the entire length of a wall, when only a small section is too narrow for grid, unnecessarily drives up the cost of the entire project.

An alternative that preserves the aesthetic options and design flexibility of smaller segmental units, such as VERSA-LOK Standard units, is to double or triple stack the units just at those places where space constraints prohibit grid. Double- or triple-stacking VERSA-LOK Standard units increases the thickness of the wall to 24 or 36 inches, respectively.

“It’s a proven solution that’s accepted by engineers across the U.S.,” says VERSA-LOK Engineering Manager Karen Nelson. “Multistacked SRWs provide a concrete mass that’s similar to big blocks, but with more design flexibility.”

Using double- or triple-stacked SRW units where grid is not an option, and single-stacking the rest of the wall, might be the most cost-effective way to accommodate space constraints on your next project. Behind the consistent face of the wall, multistacked units or grid can be used where appropriate to provide the most cost-effective solution. You retain the aesthetic appeal and design flexibility of a segmental wall, and no more material is used than is needed.

“Multistacking keeps the designer’s options open to use a weathered texture and/or a blended color for the facing units,” explains Jason Rexine, VERSA-LOK Contractor Sales Yard Division Manager in Minneapolis-St. Paul, MN. “The internal stacks should be built with inexpensive gray units to minimize cost.”

And the multistacking option can open new opportunities for SRW contractors, who can use the option to bid competitively on projects that otherwise might go to big-block installers.

So the next time you find yourself in a tight spot, call in “reinforcements.” SRWs, double- or triple-stacked, can get you out of that tight spot.

A library of detail illustrations in pdf, dwg and dxf formats is available on the VERSA-LOK website.