Unilock Home Additions & ADU Nationwide

Unilock Home Additions & ADU: The West Covina Owner’s Guide

Unilock pavers and retaining wall systems are built for heavy use, but the base materials, edge restraints, and drainage layers that support a home addition or ADU foundation work have a real lifespan in West Covina’s soil. When the paver base under your addition’s walkway, patio, or retaining wall starts shifting, you’ll see cracks, low spots, and water pooling where it didn’t before. A full Unilock paver base rebuild or edge restraint replacement for a home addition or ADU project in West Covina typically runs $4,500 – $13,000, and most jobs are done in one to three days once we’re on site. Call (341) 217-4204 for a free estimate and we’ll put the price in writing before any work starts.

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Which Unilock Models This Applies To

Unilock makes dozens of paver and wall lines, and the compatibility question matters more than most homeowners realize. For home additions and ADUs in West Covina, the systems we see most often are Brussels Block (tumbled concrete pavers in 6×9 and 9×9 profiles), Richcliff (a larger-format paver that mimics natural stone), U-Cara (multi-piece wall panels for retaining walls and ADU foundations), and Lineo (dimensional wall blocks for short seat walls and planter edges). The gotcha: Unilock pavers from different manufacturing runs can vary by up to 1/8 inch in thickness, so if you’re matching existing pavers after an addition or ADU build, we pull from the same batch lot when possible and blend from multiple pallets when not. OEM Unilock pavers are what we recommend for color-match critical areas, but quality aftermarket edge restraints and geotextile fabric hold up just as well and cost less. Sawyer Remodel West Covina is an independent service provider and not affiliated with Unilock.

Signs Your Unilock Home Additions & ADU Is Failing

• Low spots and birdbaths in the paver surface. This is almost always a base failure. West Covina’s clay-heavy soil expands and contracts with moisture, and a base that wasn’t compacted in lifts will settle unevenly. You’ll see water sitting in the same spot hours after rain.
• Pavers rocking or shifting underfoot. When the bedding layer washes out through a failed edge restraint, individual pavers lose support. You’ll feel a paver tilt when you step on it, and you may hear a hollow clack.
• Edge pavers separating from the main field. Plastic edge restraints that weren’t spiked deep enough, or that cracked from heat cycling, let the outside course drift outward. The gap widens over a season or two.
• Sand washing out between joints after rain. Polymeric sand that wasn’t activated properly, or that has exceeded its lifespan, will erode. You’ll see sand collecting at the base of downspouts and along the lowest edge of the patio.
• Retaining wall leaning or bulging. This is the one that gets serious. A U-Cara or Lineo wall without proper drainage gravel and a geogrid tieback will start to lean under West Covina’s wet-winter/dry-summer cycle. If you see a wall out of plumb, call before it gets worse.

Replacement Cost & What’s Included

For a home addition or ADU paver base rebuild in West Covina, a full teardown, re-compacted base, new bedding layer, new edge restraints, and re-installation of existing pavers runs $4,500 – $13,000 depending on square footage, access, and whether the existing pavers can be salvaged. A partial repair, like re-setting a 200-square-foot section or rebuilding a failed edge, lands at the lower end. Full base rebuilds with new drainage gravel and geotextile fabric sit at the top. Every quote includes the written price before work starts, the parts, the labor, haul-off of old material, and the 365-Day Done Right Promise: if it’s not done right, we make it right. No change orders, no surprise line items.

DIY or Call Us?

You can safely check a few things yourself: look for edge restraint spikes that have popped up, note where water pools after a storm, and mark any pavers that rock. What you shouldn’t do is pull up a section and start hand-tamping a new base. Compaction is the whole game in West Covina, and a hand tamper won’t hit the 95% Proctor density that keeps pavers flat for a decade. You also need the right thickness of Class II road base, the right bedding sand depth, and a plate compactor in the right sequence. Half-done compaction shows up as the same low spots you started with, just later. Luca Romano has watched homeowners re-do the same 10×10 patio twice because the base wasn’t right. Call (341) 217-4204 for a free estimate. Good work shows. Bad work shows up later.