On a steep Los Gatos lot, the first job is creating a flat spot. That might be a single wall that holds a patio pad, or a series of terraces stepping down the slope. Each choice has a different structural demand. A two-foot wall is a weekend of block work. A ten-foot wall holding back a road is an engineered structure with footings, drains and reinforcement.
For a segmental retaining wall, we compact a base of crushed aggregate, set the first course dead level, and build in layers of geogrid that typically extend back about 60 percent of the wall height or more, as the design calls for. Behind it goes clean drain rock and a perforated pipe that daylights somewhere safe. A wall without drainage is a pressure vessel waiting to fail.
Tall walls, walls near property lines and walls supporting structures or driveways usually need permits and an engineer. Hillside rules in town may add review on top of that. We'll tell you where we think your project falls and what to ask the town.