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Sakrete Home Additions & ADU: The Pasadena Owner’s Guide
Home additions and ADUs built on Sakrete concrete foundations in Pasadena typically run $45,000 – $130,000 fully permitted and installed, depending on square footage, site access, and whether you’re tying into an existing structure. Most owners call us when they spot stair-step cracks along the stem wall, moisture wicking up through the slab, or when an existing Sakrete-anchored ledger board shows rust bleed at the bolts. The good news: we inspect the existing concrete, tell you whether it’s structurally sound to build on, and price the foundation work before any framing starts.
We’re an independent Pasadena general contractor, not affiliated with Sakrete. But we’ve poured, patched, and built on enough of their bagged mix over the years to know exactly how it behaves in Southern California’s dry-swell clay soils around Pasadena and the San Gabriel Valley.
Which Sakrete Models This Applies To
When it comes to home additions and ADUs, “Sakrete” usually means one of three things on a Pasadena job: the original slab or footing poured from Sakrete High-Strength Concrete Mix, a Sakrete Sand Mix topping bed under tile or flooring, or a Sakrete Fast-Setting Concrete repair done on an older foundation before the addition went up. We identify what you’re working with by checking the existing concrete’s aggregate size, the presence of fiber reinforcement in a spalled edge, and any visible bag labels left behind on older DIY work.
The compatibility gotcha most owners miss: Sakrete’s 5000 PSI mix needs a minimum 3-inch slab depth to hit its rated strength. We regularly find Pasadena patios and walkway slabs poured at 2 inches or less, which is fine for foot traffic but nowhere near enough for a permitted ADU addition. If you’re building on a thinner slab, you’re either pouring new footings or reinforcing the existing concrete with doweled-in rebar. There’s no aftermarket shortcut that turns a 2-inch patio into a structural foundation. You also can’t just skim-coat a topping mix over spalled concrete and call it load-bearing. The fix is a full evaluation of what’s below grade, and that’s where we start every quote.
Styles & brands we work with
Signs Your Sakrete Home Additions & ADU Is Failing
- Stair-step cracks through the stem wall or footing. This is differential settlement, usually from Pasadena’s expansive clay soils cycling wet and dry through the year. The concrete is moving unevenly and any addition built on it will carry those cracks upward into the framing.
- Efflorescence (white chalky deposits) on the interior side of the slab. Water is migrating through the concrete. That’s hydrostatic pressure from poor drainage, and it will eat away at the slab over time and wreck any flooring you put over it.
- Rust-stained anchor bolts at the mudsill. The original bolts are corroding where the concrete stayed damp. A new addition bolted into corroded anchors is a structural liability, not a cosmetic one.
- Hollow sound when you tap the slab edge with a hammer. That’s delamination: the top layer of the Sakrete pour has separated from the base. You can’t anchor framing to a slab that sounds like a drum.
- Visible form lines or cold joints that appear to be opening. This happens when Sakrete was poured in batches too far apart to bond chemically. The joint is a weak seam that will crack under the new load of an addition or ADU.
Replacement Cost & What’s Included
In Pasadena, a full home addition or ADU with proper Sakrete-ready foundation work runs $45,000 – $130,000 depending on size and site conditions. That’s the complete project cost: plans, permitting, demolition if needed, new concrete footings and slab with the right PSI mix for structural work, framing, electrical, plumbing, drywall, fixtures, and finish work. A smaller garage conversion where the existing slab is structurally sound falls on the lower end. A detached ADU from raw dirt to certificate of occupancy lands on the higher end.
What tends to move the number most in Pasadena is site access and soil. If we’re hauling concrete by wheelbarrow down a narrow Craftsman side yard in Bungalow Heaven, that’s a different labor picture than a wide-open lot with direct truck access. We also factor in whether the existing concrete is reusable or needs partial demolition. Every quote is a written line-item price before work starts. No change orders, no surprises at the invoice. If we tell you $78,000 for your ADU, that’s the number you approve and the number you pay, unless you change the scope yourself.
See the difference
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AfterDIY or Call Us?
Here’s the honest split. You can absolutely pull a tape measure, check your existing slab thickness at the edge, and look for the cracks and efflorescence we listed above. That’s useful information, and it helps us price your job accurately on the first visit. What you shouldn’t do is attempt your own structural concrete repair on a foundation that will carry a permitted addition or ADU. The concrete is load-bearing, any mistake gets buried inside the new framing, and Pasadena’s building department will want an engineer’s stamp on anything structural anyway. That’s not a barrier; it’s the thing that keeps the building standing through an earthquake.
One more thing worth knowing: Sakrete makes different PSI-rated mixes for a reason. Using the wrong bag off the shelf at the hardware store on a stem wall repairs nothing and creates a cold joint that will fail later. If you’re seeing settlement or slab damage and you’re planning a Pasadena addition, call us at (626) 657-5396. We’ll tell you what the existing concrete can hold and what has to go.
FAQs
A properly poured and reinforced 3000 – 5000 PSI concrete foundation in Pasadena typically lasts 50 to 80 years before it needs major attention, provided the drainage around it is correct. The failures we see are almost always from water, not age. Call us at (626) 657-5396 and we’ll assess your slab before you commit to building on it.
Yes, in many cases we can repair and reuse an existing Sakrete slab by doweling in rebar, adding a properly bonded structural pour, and sealing against moisture. If the slab is thin, delaminated, or sitting on uncompacted fill, replacement is the only code-passing option. We’ll tell you which one it is before any money changes hands.
For most Pasadena additions and ADUs, the foundation and concrete phase runs two to four weeks from excavation to cured slab ready for framing. Curing time is the non-negotiable part; Sakrete and any other mix needs time to hit design strength before we bolt framing to it. We build that into the schedule so you’re never waiting without knowing why.
We use whichever concrete meets the structural spec on your permit, whether that’s Sakrete bagged mix for small pours, a bulk mix from a local Pasadena batch plant for full foundations, or specialty repair mortar for patching. We also install cabinetry from KraftMaid, countertops from Cambria and Silestone, and a full range of name-brand fixtures when your addition reaches the finish stage. For a concrete question specific to your site, call (626) 657-5396.
Ready to Price Your Pasadena Addition or ADU?
The work tells you everything. You just have to know how to listen to it. Send us photos of your existing slab, tell us what you’re planning to build, and we’ll give you a straight number. No showroom pitch, no four-hour arrival windows, no invoices that look like they came from a different job. Just a written price from Luca Romano and a crew that shows up when we say we will, with a live arrival update before we knock. Call (626) 657-5396 for a free estimate, or fill out the form and we’ll call you back.
Written by Luca Romano, Owner & Lead Contractor, Sawyer Remodel Pasadena at Sawyer Remodel Pasadena, serving Pasadena and nearby areas.
