Unilock Home Additions & ADU Nationwide

Unilock Home Additions & ADU: The Woodland Hills Owner’s Guide

If you’re planning a home addition or ADU in Woodland Hills with Unilock hardscape materials as part of the build, you’re looking at a project that typically runs $45,000 to $130,000 for the addition itself, with Unilock paver work for patios, walkways, or retaining walls adding roughly $3,500 to $11,000 depending on square footage and stone choice. Mason Remodeling Co Woodland Hills installs Unilock pavers and walls as part of full additions and ADU projects, and we keep common Unilock replacement pavers, edge restraints, and jointing sand on hand for repairs. Most homeowners discover a Unilock part has failed when pavers shift, sink, or separate at the edges after a heavy rain season in the Valley, or when a retaining wall starts leaning after years of clay soil movement.

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Which Unilock Models This Applies To

Unilock splits its product lines into paver families, and the one you own changes how a repair or addition gets priced. The most common lines we work with in Woodland Hills are Thornbury, Brussels Block, Mattoni, and Richcliff. Each has a different dimensional spec. Thornbury runs 60mm thick for driveways and 50mm for patios. Brussels Block is a tumbled paver with a 70mm thickness rated for vehicle loads, while Richcliff is a thinner, modular paver that should not carry vehicle weight. The compatibility gotcha most owners miss is this: Unilock changed the Brussels Block mold in 2018, and older pavers do not match the dimensional tolerance of current production. If you’re patching a pre-2018 Brussels Block surface, we match the older dimensions through Unilock’s legacy stock channels or a quality aftermarket equivalent, and we’ll tell you which one we’re quoting before we order. OEM Unilock pavers hold their color longer than generics because the face mix uses a higher pigment load and a harder aggregate blend, but aftermarket equivalents from Techo-Bloc or Belgard can match color within acceptable tolerance for about 15 to 20 percent less. Isaac Pruett has seen enough fading on cheap big-box pavers in the San Fernando Valley sun to recommend staying with Unilock OEM or a specification-grade match, never a hardware store brand.

Signs Your Unilock Home Additions & ADU Is Failing

• Pavers sinking in low spots. This usually means the base layer has eroded or was never compacted to spec. In Woodland Hills, expansive clay soil swells with winter rain and shrinks in summer heat, which forces the base to shift. You’ll see it most often near downspouts or along the garage apron.
• Edge restraints pulling away from the border. Plastic or aluminum edging fails when spike anchors loosen in clay soil. Once the edge is free, pavers start drifting outward and the whole surface loses its interlock.
• Joint sand washing out after every rain. Polymeric sand should form a firm bond between joints. If it keeps washing out, the original sand was never activated correctly, or the slope of the surface sends water pooling instead of draining.
• Retaining wall leaning or bulging at the middle. This is the one to take seriously. A Unilock retaining wall that leans usually means the geogrid reinforcement wasn’t installed, or drainage behind the wall has failed and hydrostatic pressure is pushing against it. Left alone, a wall can fail suddenly after a heavy storm.
• White crust forming on paver edges. Efflorescence is common in the first year but persistent white buildup usually means poor drainage under the pavers. Water is moving through the base and carrying minerals up through the stone.

Replacement Cost & What’s Included

For a Unilock paver patio or walkway replacement in Woodland Hills, expect $3,500 to $11,000 installed, which covers removing the old surface, regrading and compacting the base, reinstalling edge restraints, laying the pavers, and sealing the joints with polymeric sand. If the project is part of a home addition, the addition budget of $45,000 to $130,000 covers the structure, foundation, framing, electrical, plumbing, and finish work, with hardscape priced separately based on the Unilock product line. What drives the range on the hardscape side is base condition. If the old base was only a few inches of sand over dirt, we’re excavating deeper and rebuilding it properly. If the base is solid, the repair costs less. Every quote from us is a written, line-item price before any work starts, and the hardscape portion is covered by our 365-Day Done Right Promise: if the pavers settle, shift, or separate within a year of completion, we return and fix it at no cost.

DIY or Call Us?

You can safely check a few things yourself: look for downspouts dumping water against paver edges, check whether edge restraints are still pinned down, and note where water pools after rain. Those observations help us quote faster. What you shouldn’t do is pull up a section of pavers and rebuild the base yourself unless you own a plate compactor and understand sub-base depth in expansive clay soil. A bad DIY base repair in Woodland Hills on a pre-2018 Brussels Block install can void the interlock warranty and leave you with a wavy surface that drains toward your foundation, and that’s a far more expensive problem than the paver repair. If you’re weighing the cost of the tool rental and the cost of a failed first attempt, call us at (831) 290-6866 and we’ll give you a straight number for the repair.