Retaining wall design in Boise, Idaho

Most people start looking into retaining wall design in Boise after something goes wrong. Soil washes onto the patio every spring. An old timber wall is leaning. Or the backyard is one long slope, and there's nowhere flat to put a table.

A retaining wall holds soil back so you can have level ground on one side of it. Designing one means figuring out how tall it needs to be, what it's made of, how water gets out from behind it, and how it looks once it's done. I'm Kabe Hockema. I design and build walls as part of my work as a landscape designer, and I've been building landscapes here since 2012.

What a retaining wall is up against

The soil behind a wall is heavy, and it gets heavier when it's wet. Here in the Treasure Valley, a lot of that soil is clay. Clay soaks up water, holds onto it, and swells when it freezes. Every freeze-thaw cycle pushes on the wall a little. A wall that isn't built for that will bulge, lean or crack within a few winters.

So the design has three jobs: hold the weight, let water out, and handle the freeze.

When a yard needs one

• A slope is washing soil onto a patio, path or driveway.
• You want a flat spot for a patio or lawn in a sloped yard.
• Your lot is in the Eagle foothills, Hidden Springs or another hillside area, and the ground drops off steeply.
• An old wall made of railroad ties or loose rock is failing.
• You want raised planting beds or a seat wall that also holds back soil.

Block, stone or boulders

Segmental block. Concrete blocks that lock together, set on a compacted base. They're clean and even, and they come in many colors. They're a good fit for modern homes and walls that need to be tall.

Natural stone. Stacked stone looks like it's been there forever and suits gardens and older homes. It takes more hand work to build, so it usually costs more.

Boulders. Large rocks set in tiers. They work well on foothill lots where a natural look matters more than a straight line.

I talk through all three at the consultation. My retaining walls page has more on materials and finished work.

Drainage behind the wall

This is the part most failed walls skipped. Water trapped behind a wall adds a lot of pressure. Each wall I design gets:

• A layer of clean gravel behind the wall, so water can move down instead of pushing out.
• A perforated drain pipe at the base to carry that water away.
• Fabric to keep soil from clogging the gravel.
• A plan for where the water goes once it leaves the pipe.

If the whole yard has water problems, the wall is only part of the answer. Yard drainage handles the rest.

Height, terraces and when an engineer steps in

One tall wall is not always the best answer. Two or three shorter walls, stepped back like terraces, are often easier to build, look softer, and give you planting space between each level.

Taller walls, and walls holding up a driveway, a house or a steep hill, often need an engineer's design and a permit. Rules vary by city, so I check before a design is final. If your wall needs an engineer, I'll tell you up front.

Sometimes the slope itself needs work before any wall goes in. Reshaping the ground through grading and resloping can lower how tall a wall has to be.

Making a wall look like it belongs

A wall should match the house and the rest of the yard. I tie the stone or block color to the home, plant along the top to soften the edge, and add steps where people need to get from one level to the next. Low lights tucked into a wall cap make it look good at night and help you see the steps.

Walls are often paired with a new patio. If that's your plan, see my patio design page.

What drives the cost of a retaining wall

• Height and length.
• Material: block, natural stone or boulders.
• Digging, base prep and drainage.
• Removing an old wall.
• Steps, caps and lighting.
• Engineering and permits, if needed.
• Access. Foothill lots with tight access mean more hand work.

Where I build walls

I design retaining walls in Boise, including the foothills and Harris Ranch, and in Eagle, Hidden Springs, Star, Meridian, Garden City, Kuna, Nampa, Caldwell and Middleton. I also take projects in Sun Valley and Ketchum, where hillside lots are common.

Get a wall planned right

If you need retaining wall design in Boise for a slope, a failing wall or a level patio, schedule a consultation. I'll walk the slope with you and talk through what will hold.