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Quikrete Home Additions & ADU: The Mountain View Owner’s Guide
Quikrete concrete and masonry products are commonly specified for home additions and ADU foundations, slabs, and hardscaping in Mountain View, with typical installed project costs running $45,000-$130,000 for additions and $90,000-$220,000 for detached ADUs. We stock and install Quikrete-compatible mixes including 5000 Plus High Early Strength for post-tensioned slabs and Q-Max Pro for structural footings, with same-day material mobilization available for active jobsites. Most Mountain View homeowners discover a Quikrete-related issue when their contractor flags a failed pour, a cracked slab in the Bay Area’s clay-heavy soil, or a mismatched specification on permit drawings that won’t pass inspection.
Which Quikrete Models This Applies To
Quikrete doesn’t manufacture “home additions” as a product line, but their concrete and mortar mixes appear repeatedly in Mountain View ADU and addition specifications. The critical distinction is between structural and non-structural applications.
For foundation work, we see Quikrete 5000 Plus (compressive strength 5,000 psi at 28 days, 2,500 psi at 7 days) specified for post-tensioned slabs common in newer Mountain View builds near the San Antonio and Whisman Station areas. Quikrete Q-Max Pro (6,000 psi, air-entrainment 4-7%) gets called out for footings in the older Castro Street corridor where freeze-thaw cycling is less relevant but sulfate resistance matters in the clay soils. Quikrete Crack Resistant Concrete Mix with synthetic fibers shows up for patio and walkway pours tied to addition exits.
Identification is straightforward: the paper bag print specifies the PSI and any admixtures. The gotcha in Mountain View is permit drawings that generically specify “3,000 psi concrete” while the geotechnical report demands 4,000 psi minimum for expansive soil conditions. We’ve had to reject deliveries on three downtown Mountain View jobs where the bag mix didn’t match the soils report. OEM Quikrete from authorized distributors carries batch certification; aftermarket gray-market bags, sometimes found at discount building supply yards, don’t. For permitted work, we require mill certs every time.
Signs Your Quikrete Home Additions & ADU Is Failing

- Hairline cracking across the slab within 30 days of pour. This usually indicates excessive water added at the truck or site, dropping the effective PSI below spec. In Mountain View’s summer-dry climate, premature surface evaporation before final set causes plastic shrinkage cracks that widen into structural problems.
- Spalling or surface flaking on exterior slabs. De-icing salts are rare here, but irrigation overspray on poorly sloped patio slabs creates the same chemical reaction. The top 1/8-1/4 inch delaminates, exposing aggregate and reducing cover over any embedded reinforcement.
- Differential settlement visible at the addition-to-existing junction. Bay Area clay expands and contracts with moisture; a Quikrete slab poured without proper subgrade preparation or lacking control joints at correct spacing (typically 24-30 times slab thickness in feet) will crack vertically rather than horizontally.
- White efflorescence blooming on basement or stem walls. This signals moisture migration through the capillary network of the concrete, often from inadequate dampproofing or a missing vapor barrier beneath the slab. In Mountain View’s older homes near Old Mountain View, we’ve traced this to original construction that predated modern moisture management.
- Permit hold or inspection failure on the concrete pour. The city inspector rejects the slab because the batch ticket doesn’t match the approved plans, or the slump test exceeds 4 inches for footings. This stops the job cold until a structural engineer reviews and the re-pour is scheduled.
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Home addition projects in Mountain View using Quikrete or equivalent concrete products range from $45,000 to $130,000 for attached additions, and $90,000 to $220,000 for detached ADUs. What drives the spread: foundation depth and type (stem wall vs. post-tensioned slab), square footage, utility trenching length, and whether the Mountain View ADU ordinance requires covered parking or bike storage that adds slab area.
Our quotes itemize concrete as a line item: material per cubic yard at distributor net pricing, plus pump or buggy service if site access is tight (common in the Rengstorff Avenue and downtown grid areas with zero lot lines). Labor includes formwork, rebar or post-tension cable placement, pour, finish, and cure protection. Under Clause 1 of the Haven Standard, that written price is delivered before any work starts. The 365-Day Done Right Promise covers defects in workmanship; material warranty runs through Quikrete’s published guarantee when we source through authorized distribution.
DIY or Call Us?

A homeowner can safely verify the bag specification against the permit set: check the PSI, the air content if specified, and the batch date (Quikrete portland cement blends have a 12-month shelf life in dry storage, shorter in Mountain View’s humid winter sheds). You can also confirm the subgrade is compacted and the vapor barrier is intact before the pour.
Where DIY goes wrong is in the pour itself. Concrete waits for no one. A single-carpenter homeowner with a wheelbarrow cannot place and finish a 20×24-foot ADU slab before the initial set begins, especially in warm weather when Quikrete 5000 Plus sets faster than standard mixes. Improper finishing traps bleed water, weakens the surface, and voids most manufacturer warranties. And post-tension cable systems are genuinely dangerous: the cables are tensioned to 33,000 PSI after the concrete cures, and a cut or improperly anchored cable can release lethal energy. We don’t recommend homeowner involvement beyond observation and documentation. Call (669) 215-4852 to schedule your free estimate; we’ll review your permit status and give you a written scope and price before any Quikrete gets mixed.
FAQs
Properly specified, placed, and cured Quikrete concrete should exceed 50 years in Mountain View’s climate, though clay soil movement and inadequate moisture barriers are the usual failure modes, not the material itself. Call (669) 215-4852 for an exact quote on your foundation scope - estimates are free.
Hairline cracks can be epoxy-injected; structural cracks wider than 1/4 inch or with vertical displacement usually indicate subgrade failure and require engineered repair or replacement. We provide a Free Second Opinion on any written estimate from another contractor, reviewed line by line at no charge.
Form and pour for a typical 400-square-foot ADU slab takes 3-5 working days including inspection holds; post-tensioned slabs add 7-10 days for stressing and grouting. Our documented photo record on every visit shows you each phase as it completes.
We don’t carry bagged concrete on service vehicles - it has a short working life once mixed - but we maintain same-day sourcing relationships with authorized Quikrete distributors in San Jose and Redwood City, and we stock compatible accessories including vapor barrier, rebar, and post-tension hardware. Every crew is background-checked and uniformed, and a live person answers calls 24/7.
Written by Grant Rowan, Owner, Rowan Construction Group Mountain View at Rowan Construction Group Mountain View, serving Mountain View and nearby areas.







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