Tom Zakoski, from Burnsville, Minnesota, is an award-winning landscape designer with Villa Landscapes, a design/build division of Twin Cities’ do-it-yourself landscape retailer, Patio Town. He spoke with Total Landscape Care about the growing popularity of functional and fashionable retaining walls.
TLC: What are the hot trends in retaining wall design?
TZ: Demand is strong for the natural stone look using weathered-textured retaining wall block (the Versa-Lok brand is a good example). The use of multiple size blocks within the walls gives it a natural weathered look and is a popular choice. But the biggest trend is using retaining wall blocks to build freestanding walls that create courtyard sides, seat walls and benches. One of my most requested backyard items is a circular patio with a seat wall around it and a fire pit in the center. Another highly requested feature is for columns that we build into our walls or as a freestanding item. Color choices include specialty color blends and mixing colors to produce earth tones.
TLC: Are homeowners becoming more environmentally conscious with their landscape choices?
TZ: We are a very green industry to begin with but we are seeing more landscape elements such as retaining walls used to help control problems such as drainage and slope issues.
TLC: What kind of retaining wall design is the most popular choice?
TZ: A straight face block is the leading traditional choice of most consumers and designers. These blocks have a cleaner-line look which helps set off curved walls. The straight face block also maintains a sleeker appearance because of the lack of crevices in the tri-face block forms.
TLC: What are elements of good design for a retaining wall?
TZ: Good design avoids making the concrete wall a cold, austere, dominating focal point in the landscape. I try to soften the overall look by terracing my walls to help break up any massive height and allow for plants and a blended color block to create a harmonious effect.
TLC: What are some installation challenges?
TZ: The biggest challenge our firm runs into is access, since the majority of our work is renovation work. The other is managing the often-large staging areas required in the construction of a wall.
TLC: From a landscaper’s perspective, what’s involved in construction of a retaining wall?
TZ: Construction of a retaining wall involves many steps in construction and a very good schedule. The first challenge is always determining access to a site and the amount of space on the site to stage materials for the project. The first step in the construction process is to excavate for the base course in order to have soil coming out of the site, granular base going in to form the base pad. At the same time, the base course of block is being set. There’s a lot going on at one time and it’s crucial to have a good schedule of materials coming and going from site but never having too much at one time to complicate any process on site. Once the base course is set the rest of the blocks are placed in the wall and the wall is backfilled with drainage material and any other back fill soil. Throughout the construction process the biggest challenge is for the contractor to be on top of the scheduling of materials and labor to keep the project on time and within budget.
TLC: Function or fashion? What’s more important?
TZ: Function is the most important part of a retaining wall since the wall is built to stabilize the earth behind it. But the walls can add aesthetic beauty as well.
TLC: Do retaining walls add to the property value?
TZ: Even more than adding value to a property, retaining walls make a property more useful. This can be done by making a steep hill that is impossible to maintain more manageable, or a sloped yard more level. Adding use increases value.
TLC: How can you get a great look without spending a fortune?
TZ: The condition of the site will always have the biggest impact on the project price. Considering the main purpose of a retaining wall is to hold back the earth, this is not project one wants to use inferior products or cut corners on installation. A failed wall will cost much more than a properly installed wall.