Unilock Home Additions & ADU Nationwide

Unilock Home Additions & ADU: The Los Angeles Owner’s Guide

Unilock pavers, retaining wall systems, and hardscape components used in Los Angeles home additions and ADU projects typically run $53,100 to $153,400 installed, depending on scope, soil conditions, and whether the project ties into an existing foundation. We stock Unilock-compatible materials and can usually begin material procurement within 48 hours of a signed agreement. Most Los Angeles homeowners discover their Unilock hardscape needs attention when settling cracks appear in a patio that was supposed to be floating, or when water starts pooling against an ADU foundation where the permeable base has compacted unevenly.

Call (213) 652-7670

Which Unilock Models This Applies To

Unilock’s product lines for residential additions and ADU hardscape fall into three categories: the U-Cara multi-face wall system, Brussels Block and Richcliff paver families, and the Concord Wall structural series used for grade transitions and planter integration. The model number is stamped on the underside of pavers and on a cast label on wall units, usually paired with a date code that matters for warranty tracking.

The critical compatibility gotcha in Los Angeles is the ASTM C936 specification for vehicular-rated pavers versus the ASTM C1781 pedestrian rating. We’ve seen ADU driveway extensions in Silver Lake where a homeowner sourced leftover Brussels Block from a backyard job, not realizing it was the pedestrian mix; the surface spalled within 18 months under a compact SUV. For load-bearing applications, the paver must be 80mm minimum thickness with an edge chamfer that matches the original run.

We source OEM Unilock through authorized distributors in the San Fernando Valley. Aftermarket equivalents exist from Belgard and Techo-Bloc, but color matching is approximate at best; the iron oxide pigments weather differently under Los Angeles UV. If your addition ties visually to existing hardscape, OEM is the only honest recommendation.

Signs Your Unilock Home Additions & ADU Is Failing

• Stepping or rocking underfoot. The bedding sand has washed out or the edge restraint has failed, usually because the ADU’s downspout was routed incorrectly and water is undermining the base. In Los Angeles, where we get intense rain bursts followed by months of dryness, this cycle accelerates.
• Efflorescence that keeps returning after cleaning. White mineral bloom indicates moisture is migrating through the joint sand from a trapped source, often a compromised vapor barrier where the hardscape meets the addition’s foundation.
• Cracking along control joints that don’t align with saw cuts. The slab or paver base is experiencing differential settlement. In the Baldwin Hills area, we’ve traced this to expansive clay soils that weren’t properly pre-soaked before base compaction.
• Wall units tilting or separating at the setback. The geogrid reinforcement was either omitted, placed at the wrong elevation, or insufficient for the surcharge load of the ADU’s roof runoff. Unilock’s Concord Wall requires grid at 16-inch vertical intervals minimum for walls over 28 inches.
• Joint sand disappearing and weeds establishing. Polymeric sand breaks down under pressure washing or wrong product selection; Los Angeles homeowners often use play sand or concrete sand, neither of which locks the joint.

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Replacement Cost & What’s Included

For a Unilock hardscape repair or rebuild tied to a Los Angeles home addition or ADU, expect $53,100 to $153,400 for the full project scope. Isolated paver reset or wall rebuild sections run lower, but we quote only after exposing the base to confirm substrate condition.

What drives the range: soil prep depth (12 inches versus 6 inches of aggregate base in expansive soil zones), drainage integration with the ADU’s foundation waterproofing, and whether we’re matching discontinued Unilock colors that require custom blending. Every quote is flat-priced with line-item scope, written warranty, and a documented photo record included as standard. Under Clause 1 of the Haven Standard, no work begins until the price is written and signed.

DIY or Call Us?

An owner can safely check: whether downspouts discharge onto the hardscape, whether joint sand level is within a quarter-inch of the paver chamfer, and whether wall drainage weep holes remain unobstructed. These are visual inspections, not repairs.

Where DIY goes wrong: resetting pavers without recompacting the base in lifts, using plate compactors without protective mats that chip Unilock surfaces, and guessing at geogrid lengths. Wall failures are genuinely dangerous; a 4-foot retaining wall with saturated backfill can exert over 2,000 pounds per linear foot of lateral pressure. We’ve rebuilt three Concord Wall systems in Los Angeles where the homeowner omitted grid entirely, not understanding that the setback angle provides stability only when reinforced.

Call (213) 652-7670 and we’ll schedule a free estimate with written scope and photo documentation of what we find.

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