When built with attention to style and proper engineering, retaining walls can become an attractive part of any landscape design. Whether for landscape grading, defining spaces around fire pits or pool areas, or simply to accentuate raised beds, retaining walls can add depth, dimension, and visual appeal to any lawn.
Here are seven steps to consider when working with clients to design and install retaining walls.
1. Use the proper material for the job.
Some small retaining walls are primarily aesthetic, while other, tall walls have to be strong enough to support an entire slope of dirt and turf. Aaron Gunter, chief operating officer at Willow Branch Landscapes in Brentwood, Tennessee, typically turns to budget-friendly segmental block as the firm’s go-to retaining wall material.
This past summer, the crews at Landscape Consultants in New Cambria, Kansas, worked on many retaining wall rebuild projects, says Dan Fiorillo, the company’s lead designer and salesperson. “We’ve had a lot of work repairing and redoing walls (installed by others) that have failed recently,” Fiorillo says. “It’s proof that you have to choose your stone correctly. Some stones are not meant to be put in the ground or near the ground because of how much moisture they can retain.”
2. Visit the site during planning and design.
It’s important to visit your clients’ sites in person to determine the lay of the land and scope of the project. “We meet at the client’s house so we can walk out into the yard and walk through the actual layout of the space with them,” says Chris Geryak, designer and project manager for MG Landscape and Irrigation Contractors in Indianapolis.
Fiorillo suggests bringing your crew foreman along on the site visit to draw him or her into the design discussions. “Getting the foreman involved on the design end of it lets you get input on ways he might see to cut costs and streamline the installation,” Fiorillo says.
3. Build a visual catalog of your past work.
Creating a visual catalog of your firms’ past retraining wall projects is worth the effort since it helps future clients see the wall styles and materials available to them – and visualize the look they want for their own home or business.
Geryak typically carries a tablet with digital photos of completed wall projects that he can email to clients for their consideration. Fiorillo has found that showcasing a past project catalog not only helps ease the design process with new client, but it also serves as a marketing tool of sorts.
4. Be open to new methods, styles and products.
Some clients simply prefer the look of natural stone. In Fiorillo’s Kansas market, many clients lean toward either dry-stacked or mortared natural stone retaining walls, rather than segmented blocks, he says. For those clients needing a less expensive option, segmented block manufacturers are increasingly offering designs and product lines that mimic the natural stone look. “Going into the higher end market, there are (segmented) products that mimic that natural stone look versus just a typical split face block,” Gunter says.
In addition to natural stone walls and dry stack walls – which also remain popular in Gunter’s Tennessee market – Willow Branch crews sometimes use a thin veneer over traditional concrete masonry unit wall blocks to achieve a natural stone look. At other times, Gunter’s team has strategically placed large natural stones – some as much as 5,000 pounds each – to create bolder-stacked walls.
“We meet at the client’s house so we can walk out into the yard and walk through the actual space with them.” Chris Geryak, MG Landscape and Irrigation Contractors
5. Get plans approved by an engineer.
To help ensure that the retaining wall is being designed and built properly, both structurally and to match the lay and quality of the soil where it will stand, it’s a good idea to have your build reviewed and approved by a structural engineer. This will add a significant cost – perhaps $1,500 to $3,000 or more – to your overall bid, but firms who adopt this approach feel it’s worth it.
“We don’t build any wall without an engineer’s stamp,” Gunter says. “Every site and every soil around here is different, and there’s always a different challenge at each site, especially when you get into the larger walls.”
6. Prep the site properly.
Like Fiorillo, in recent years, Geryak has seen an increase in jobs to repair or rebuild failed retaining walls built by others. The root cause of many of those failures: poor site preparation. “They were not done with proper backfill of the soil underneath,” Geryak says. To ensure that new wall installs last, take the time to use quality draining and backfill material rather than just filling in with whatever is already on site.
“Using good clean rock and the best draining base material that you can means the less callbacks you’re going to have down the road,” Fiorillo says. “We use a lot of crushed concrete (for base material) and behind the wall we like to use clean washed crushed rock, because the water percolates through it better. Going those extra steps makes a big difference in the long run.”
7. Add finishing touches.
Attention to finishing details can transform a purely functional wall into a landscape showpiece. Rather than rigid straight lines, Gunter prefers to design walls with long, sweeping curves, surrounded by landscaping. Additionally, to avoid abrupt wall edges, he typically prefers to curve the ends back into a graded bank or lawn line, he says. For the top accent, the Willow Branch team always installs a cap of some type, whether a natural stone cap or one provided by the manufacturer.
Above all, it’s important to talk with your clients through every aspect of the design so that they’re happy with the end result.
“You want to visit the site with them to imagine the site lines from across the whole home and yard,” Gunter says. “Will they see the walls every day outside of their kitchen window, or is it going to be something hidden below a hillside? Those factors play into helping your client choose the right look and the right building product.”