Block and Stone Retaining Walls in Brentwood, CA

Segmental block walls

Segmental retaining wall block is an interlocking concrete unit, stacked without mortar on a prepared base. It comes in many colors and textures, and it can follow curves and steps. On taller or more heavily loaded walls, contractors often tie the wall into the soil with geogrid, a reinforcing fabric laid between courses. Whether a wall needs it, and how it's designed, depends on the site.

Stone veneer and boulder walls

• Stone veneer: real or manufactured stone applied over a concrete or block wall for a natural look.
• Boulder and rock walls: large stones set by equipment, common on rural lots and slopes.
• Dry-stack and mortared stone: built stone by stone; labor-heavy and priced accordingly.

The look and the limits

Block and stone give you the most visual choice. The limits are height, soil and drainage. Any wall holding back soil needs water to drain from behind it, and Brentwood's code limits wall height (see below). If a wall is tall, holds back a driveway or sits near a building, expect the contractor to talk about engineering.

What block and stone walls cost

HomeGuide lists concrete block at $15–$40 per square foot and natural stone at $20–$95 (HomeGuide). Angi gives stone as $20–$100 per square foot (Angi). For 3–6 ft interlocking block walls, HomeGuide's concrete guide shows $45–$210 per linear foot (HomeGuide concrete). See the cost guide for worked examples.

Permits and engineering

The City of Brentwood says retaining walls shall not exceed four feet, that a taller embankment is benched into walls no higher than four feet each, and that a building permit is required over four feet or when a wall supports a surcharge (Municipal Code §17.660.008). It is a common reason homeowners need a contractor even for walls built from retail block. See the permit guide.

Compare other materials

See concrete walls, wood walls, or all three compared.