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Quikrete Home Additions & ADU: The Los Angeles Owner’s Guide
If you’re planning a home addition or ADU in Los Angeles and want Quikrete concrete products used properly in the foundation, stem walls, footings, and slab work, we install those systems every week. A full home addition in Los Angeles typically runs $53,100 – $153,400 installed, and a complete ADU build lands between $106,200 and $259,600 depending on square footage, site access, and foundation conditions. Most owners reach out to us after they’ve watched a handyman pour a slab that cracked within a year, or after they’ve been told their hillside lot needs a foundation engineered with pier-and-grade-beam work that a standard crew won’t touch. Here’s the reality: Quikrete makes excellent bagged concrete and mortar mixes, but the product is only as good as the subgrade prep, rebar schedule, and curing process behind it. In Los Angeles, with expansive clay soils in neighborhoods like Silver Lake, Eagle Rock, and the hills above Studio City, the difference between a slab that stays put for 30 years and one that heaves in two comes down to who’s placing it and whether they followed the structural drawings to the letter.
Key Takeaways:
- Home additions in Los Angeles run $53,100 – $153,400; ADUs run $106,200 – $259,600.
- Quikrete products are excellent, but improper mix ratios, cure times, or subgrade prep will ruin any pour.
- We deliver a written price before any work starts. No verbal estimates that grow on the final bill.
- Every crew member is verified by name and photo before they reach your door. That’s the Threshold Standard.
- 365-Day Done Right Promise: if the work isn’t right within a year, we make it right at no cost to you.
Which Quikrete Models This Applies To
Quikrete isn’t a single product line; it’s a family of bagged concrete, mortar, stucco, and resurfacing mixes, and the right one depends entirely on the job. For home additions and ADU work in Los Angeles, we’re typically placing Quikrete 5000 High Early Strength Concrete for footings and stem walls where the structural engineer specifies a 5,000 PSI mix, Quikrete Crack-Resistant Concrete for interior slabs and non-structural flatwork, and Quikrete All-Purpose Gravel for subgrade base under slabs. The compatibility gotcha most people miss: Quikrete 5000 cures fast, which is great for reducing form time, but it means you have less working time in hot Los Angeles afternoons, especially in the San Fernando Valley where summer temps hit triple digits. You either add water and lose PSI strength, or you don’t add water and lose workability. A crew that knows the Valley heat knows to schedule pours for early morning, use cold water, and keep a hose and wet burlap on hand for cure. The OEM-versus-aftermarket question here is less about the bag and more about the placement: we use Quikrete products because they’re consistent batch to batch, which matters when you’re pouring a foundation that’ll carry a second story.
Styles & brands we work with
Signs Your Quikrete Home Additions & ADU Is Failing
- Diagonal cracks climbing from corners of windows or doors. This usually means differential settling: one section of the slab or stem wall is moving more than the section next to it. In LA hillside areas, it’s often a sign that undermined fill was never compacted to spec before the pour.
- Hairline spider-webbing across interior slabs. This is typically shrinkage cracking from water added at the job site to make the mix easier to spread. It weakens the surface and eventually spalls, especially where floor traffic is constant.
- Efflorescence, or a chalky white powder blooming on concrete surfaces. Water is moving through the slab and carrying mineral salts to the surface. It means the vapor barrier under the slab either wasn’t installed or was punctured during placement.
- Slab edges crumbling or chunking out near exterior walls. In Los Angeles, this is often rain-water splash erosion combined with a too-thin slab edge that wasn’t formed with a proper thickened edge detail. Once the edge goes, rebar starts rusting, and the problem accelerates.
- Doors and windows sticking in rooms built over the slab. The slab is moving. In areas like the Crenshaw corridor or parts of Inglewood with known expansive clay, a slab poured without proper moisture conditioning of the subgrade will move every wet winter and dry summer, for the life of the building.
Replacement Cost & What’s Included
A full home addition in Los Angeles runs $53,100 – $153,400. An ADU build runs $106,200 – $259,600. What moves the number: structural engineering requirements, soil conditions, hillside or flat lot, site access for concrete trucks or pumpers, permitting fees with LADBS, and whether your existing structure needs retrofitting to tie into the new foundation. On easier accessible flat lots in neighborhoods like Reseda or Northridge, a straightforward slab-on-grade addition with standard stem walls will land on the lower end. On hillside lots in Mount Washington or Baldwin Hills where we’re drilling caissons and tying into bedrock, costs climb fast. What’s included in our number: the written engineering scope, permits pulled and inspections passed, excavation and subgrade prep, all rebar and form work, the Quikrete mix and placement, curing, and rough plumbing and electrical stubs as specified. You get a written price before any work starts, and a written guarantee stating coverage terms plainly for 365 days from the completion date. We don’t do change orders without your signed approval first.
| Project Type | Typical Installed Range (Los Angeles) |
|---|---|
| Home Addition | $53,100 – $153,400 |
| ADU Construction | $106,200 – $259,600 |
| Garage Conversion | $35,400 – $94,400 |
| Paver Driveway (for comparison) | $8,260 – $21,240 |
| Concrete Driveway (for comparison) | $5,310 – $14,160 |
See the difference
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AfterDIY or Call Us?
Pouring a post base for a mailbox? Mixing Quikrete in a wheelbarrow on a Saturday is fine. Pouring a foundation for an addition or ADU in Los Angeles is a different animal entirely, and here’s why: if you get the soil compaction wrong, the rebar clearance wrong, the form height wrong, or the mix water wrong, you’ve just spent thousands of dollars creating a structural liability under your own house. There’s no un-pouring a bad slab. You’re also pulling permits with LADBS, and if the inspection fails because the rebar is too close to the edge of the form or the subgrade wasn’t moisture-conditioned, you’re chipping it out and starting over. We’ve seen homeowners lose $8,000 on a bad DIY slab pour in Sun Valley, then pay us to tear it out and repour it correctly. Safe move: we handle the structural work. You handle the paint colors. Call (213) 632-5711 for a free estimate, and we’ll give you a written number before anything gets started.
FAQs
A properly placed Quikrete foundation with correct subgrade prep, rebar, and curing should last 50 to 80 years or more, and in Los Angeles’s mild climate with proper drainage, we’ve inspected slabs from the 1940s still performing fine. The failure point is almost never the concrete itself; it’s water, soil movement, or bad placement.
It depends on the crack width, depth, and whether it’s still moving. Hairline shrinkage cracks can often be epoxy-injected or sealed. Structural cracks from settling or heaving usually mean the foundation beneath the slab needs attention first, otherwise the same crack comes right back. We’ll assess it and give you a written recommendation, not a guess.
The pour itself is usually one day from form-setting through finished troweling. Quikrete 5000 reaches structural strength in about 7 days and full design strength in 28 days, though we can frame on it sooner once the structural engineer signs off on cylinder breaks. Site prep and form work add a few days before the pour.
We source Quikrete bagged product per job based on the structural drawings, because the mix type matters: you don’t substitute a general-purpose mix for a 5000 PSI structural spec. We also carry the accessories that matter on the truck, including rebar chairs, wire mesh, vapor barrier, and expansion joint material. We also work with other brand partners like KraftMaid, Cambria, and Silestone for interior finish work tied to additions.
Call for a Free Estimate
If you’re planning a home addition or ADU in Los Angeles and want the foundation done once, correctly, by a crew you can identify at the door, call (213) 632-5711. A live person answers every call, every day. We’ll schedule the estimate, give you a written price before any work starts, and every person who shows up will have already been introduced to you by name and photo. Isaac Pruett grew up in the San Fernando Valley and has spent two decades running residential and light commercial jobs across LA County, and he still checks every level line before his first cup of coffee. Know who’s coming, know what it costs, know it’s guaranteed, everything else is just noise.
Written by Isaac Pruett, Owner, Mason Remodeling Co at Mason Remodeling Co Los Angeles, serving Los Angeles and nearby areas.
