Small retaining walls are often DIY-able, but still require that you know what you’re doing. Even a 1-metre-tall wall might be subject to dozens of tons of pressure.
More often than not, a retaining wall needs to be designed by a professional geotechnical engineer. An engineer can create the right design for the size and stress and ensure that the wall has good drainage—both absolutely critical.
“The general rule of thumb in the construction world is that a retainer wall over four feet tall should be left to the experts,” says Shane Dutka, Founder & General Manager of Review Home Warranties. “Given how structurally important they are, and how expensive a mishap is, I advise going with a professional to plan and install your retainer wall. It’s worth the cost just from a safety standpoint.”