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Unilock Home Additions & ADU: The Santa Clarita Owner’s Guide
If you’re planning a home addition or ADU in Santa Clarita with Unilock products specified for hardscape, foundation border, or retaining elements, the typical installed project range is $45,000 – $130,000 for an addition, and $90,000 – $220,000 for a full ADU construction. We stock and work with Unilock-compatible materials on these projects, and we provide a written price before any board goes down. Most Santa Clarita homeowners reach out when they notice an existing Unilock edge course separating, a paver border on a patio addition settling, or they’re planning new square footage and want the Unilock look carried through without a mismatched seam between old and new.
Here’s the reality we see in neighborhoods like Valencia, Saugus, and Canyon Country: Unilock products are superb, but a home addition or ADU never touches just one material. The failure point is almost always the transition, where a new slab meets an existing Unilock paver edge, or where a retaining course has to carry more load than it was set for. We’ll get into exactly how to spot that, what it costs to make right, and how to plan an addition so the Unilock work doesn’t become the weak point.
Which Unilock Models This Applies To
Unilock makes several paver, wall, and edge product lines that show up in Santa Clarita additions and ADUs. The ones we handle most often are the Estate Stone, U-Cara Multi-Face Wall System, and Brussels Block lines, along with the Lineo Dimensional Stone for clean modern edges. Each has different depth specifications and base requirements, and that’s where compatibility gets real. A Brussels Block paver set on a 6-inch compacted base behaves differently than an Estate Stone slab set on a 4-inch base, especially on the clay-heavy soils common through the Santa Clarita Valley.
Here’s the compatibility gotcha worth checking before you match anything: Unilock pavers designed for pedestrian patios are not rated for the point loads a new addition’s edge or an ADU’s foundation drain will put on them. If a previous project used a 60mm pedestrian paver and your addition now introduces a roof water run-off concentrated at that edge, the base will erode and the course will settle within two wet seasons. We verify paver depth, base depth, and whether the original installation used geotextile and edge restraint. For OEM versus aftermarket, Unilock’s own edge restraint and polymeric sand are worth staying with, because third-party sand blends don’t bind to Unilock’s chamfered profiles the same way, and the joints will open in Santa Clarita’s dry-summer, wet-winter cycle.
Styles & brands we work with
Signs Your Unilock Home Additions & ADU Is Failing
- Edge course separation at the addition seam. Where new concrete meets existing Unilock pavers, you’ll see a widening gap as the two materials expand and contract at different rates. The cause is almost always a missing isolation joint or improper base compaction at the transition, not the pavers themselves.
- Settling or heaving along the addition’s perimeter. The Unilock course drops or lifts, creating a lip you can catch a shoe on. This is usually base erosion from roof run-off or irrigation overspray finding its way under the edge course, and it worsens after the Santa Clarita rainy months.
- Retaining wall blocks sliding or rotating near the new foundation. If your ADU sits into a slope and the Unilock wall behind it starts to push out, the original wall wasn’t built for the new surcharge load. This needs an engineer’s eye, not just a reset of the blocks.
- Polymeric sand failing repeatedly in specific joints. You re-sand, it looks clean, and within months the same joints are empty and ants are moving in. That’s water channeling through the joint from a drainage change your addition created.
- Unilock pavers cracking directly under downspout discharge points. A concentrated roof water stream is hitting the same paver repeatedly, and over two or three years the freeze-thaw or wet-dry cycle will fail it. The fix is about redirecting water, not replacing one paver.
See the difference
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AfterReplacement Cost & What’s Included
For Santa Clarita homeowners, the range depends on what’s failed. A localized edge-course reset with new base and edge restraint in the $2,000 – $6,000 range is common, but a full Unilock surround tied into an addition or ADU can run $10,000 – $30,000 as part of the larger project, on top of the $45,000 – $130,000 addition itself or $90,000 – $220,000 ADU construction. What drives cost: whether the original base stone is still sound, how much excavation is needed to re-establish the proper slope, and whether your existing Unilock product line is still in production or needs a matched substitute.
Every quote we write in Santa Clarita is a fixed line-item price. You’ll see the cost of base stone, sand, edging, the Unilock material itself, labor, and haul-away, all spelled out before work starts. We don’t change the number after the crew arrives. The 365-Day Done Right Promise stays on every Unilock-related project: if the course settles again within a year, we return and make it right.
DIY or Call Us?
You can absolutely inspect the damage yourself. Walk the perimeter, look for standing water after rain, check whether the edge restraint is visible or has pulled away, and take photos. That kind of observation helps you understand what you’re dealing with, and it helps us scope the job before we arrive for the free estimate.
What we don’t recommend is pulling up and resetting Unilock courses on an addition or ADU edge yourself. The base compaction, slope, and drainage correction need to be done together, and if a retaining wall intersects the addition’s foundation, the load path matters. That’s not a weekend reset; that’s a structural sequence. If you’re unsure, call us at (661) 542-4056 and we’ll walk you through what you’re seeing. The estimate is free, and the price on the paper is the price on the invoice – we put that in writing before the first board goes down.
FAQs
A properly installed Unilock surface on a correct base should hold for 20 to 30 years, but the failure point in Santa Clarita is nearly always the base drainage or the transition to new concrete, not the paver itself. If the base erodes, the pavers on top will move within a few seasons regardless of the product warranty. Call (661) 542-4056 and we’ll tell you honestly whether your issue is the material or what’s underneath it.
In most cases, a localized edge course can be repaired and re-compacted without replacing the entire paver field, as long as the base stone is still intact and the edge restraint can be re-established. Full replacement usually only makes sense when the base has washed out across a wide area or the product line has been discontinued. Call (661) 542-4056 and we’ll give you a straight read, free.
A typical edge-course reset takes two to three days, including base removal, re-compaction, paver re-set, and joint sand. A larger Unilock surround tied to an active addition or ADU project runs in sequence with the framing and site work, so timing depends on the full job schedule. We’ll tell you the actual duration in the written estimate, not a ballpark.
We order Unilock product lines directly per project from local distributors serving the Santa Clarita Valley, and we don’t substitute a different manufacturer without your written approval. If your existing line has been discontinued, we’ll bring you matched samples for an honest comparison before anything is ordered. Call (661) 542-4056 and we’ll check availability on your specific line.
If you’re planning an addition or ADU in Santa Clarita and want the Unilock work handled by a crew that leaves the site clean and the price fixed, call (661) 542-4056 for a free, written estimate. We’ll walk the property with you, name what needs to happen in sequence, and put the number on paper before any work starts. We also work with KraftMaid, Cambria, and Silestone for the interior finishes that go alongside your outdoor Unilock investment.
Written by Graham Stein, Owner, Elmstead Remodeling Santa Clarita at Elmstead Remodeling Santa Clarita, serving Santa Clarita and nearby areas.
