Licensed Concrete Contractor | San Diego County

Foundation Construction in San Diego, CA

Concrete foundations for ADUs, garages, additions, and new construction throughout San Diego County.

San Diego Concrete Co. pours concrete foundations in San Diego and throughout San Diego County for ADUs, garage additions, covered structures, and new construction. Every concrete foundation project in San Diego requires permits and inspections — we handle the coordination and work from engineered plans when the scope requires them.

Foundation concrete in San Diego needs to account for soil conditions that vary across the county. Coastal and hillside areas bring different drainage considerations than inland cities like El Cajon, Santee, and Escondido, where expansive clay soil puts more lateral pressure on footings and slabs. We assess soil conditions and drainage at the site before any concrete is placed.

Get a Free Driveway Estimate

Fill out the form and we'll be in touch within one business day. Or call us directly at (559) 510-6005, Monday through Saturday, 7am to 6pm.

How Foundation Projects Work

Plans and permits - Foundation work requires a building permit through the City of San Diego or the county depending on location. Projects that require engineered plans — most ADUs, additions, and any project with structural load requirements — are coordinated before a shovel goes in the ground.
Excavation and layout - We excavate to the required depth, lay out the foundation footprint, and install forming, rebar, and any required hardware before the pour. Layout accuracy matters — any error here carries through to framing and finish work above.
Footing inspection - Most permitted foundation projects require a footing inspection before concrete is placed. We schedule and coordinate that inspection so the job doesn't sit waiting on a missed step.
Pour, finish, and cure - Concrete is placed, finished to spec, and allowed to cure to the required strength before framing loads are applied. We confirm the cure schedule with the general contractor or owner before handoff.

WHAT WE DO

Concrete Foundation Types in San Diego

Monolithic Slabs

A single continuous pour combining the slab and footing in one operation. Standard for garages, detached ADUs, and light additions on level ground with stable soil. The most common foundation type for residential work throughout San Diego.

Stem Wall Foundations

A raised perimeter wall supports the floor slab above grade, creating space for a crawl space or meeting code requirements for specific soil or site conditions. Used when slabs on grade aren't suitable for the site or the structure.

Footings and Piers

Individual concrete supports at load-bearing points for decks, covered patios, pergolas, and point-load structures. Depth and diameter are determined by load calculations and the building department's requirements for the specific project.

Grade Beams

Reinforced concrete beams at grade level that distribute structural load across a wider footprint. Used on sites with expansive soil conditions where a standard monolithic slab may not provide enough load distribution to prevent differential movement.

Permits and Inspections for Foundation Work in San Diego

All foundation construction for structures in San Diego — ADUs, garages, additions, and new construction — requires a building permit before work begins. Jurisdiction depends on whether the property is within an incorporated city like San Diego, Chula Vista, or Carlsbad, or in unincorporated San Diego County. We confirm the correct permitting authority for your address during the estimate.

Most permitted foundation projects require a minimum of two inspections: one before the pour to verify layout, rebar, and forming, and a final inspection after completion. We schedule and coordinate all required inspections as part of the job.

Why San Diego Concrete Co.

Licensed concrete contractor serving San Diego and San Diego County
15+ years of experience on ADU, garage, and addition foundations throughout the county
Permit coordination and inspection scheduling handled — no separate contractor needed
Works from engineered plans when required by scope or the building department

Starting a Foundation Project in San Diego?

Get a free estimate from a licensed San Diego concrete contractor. We work Monday through Saturday.

Call (559) 510-6005 | Request a Free Quote

COMMON QUESTIONS

Frequently Asked Questions

Do all foundation projects in San Diego require a permit?

Yes. Any foundation for a structure — ADU, garage, addition, or new construction — requires a building permit before work begins. Small footings for non-structural elements like garden sheds may fall below the threshold in some jurisdictions, but anything structural requires a permit. We confirm the requirement and submit the application as part of the project.

What foundation type is right for an ADU in San Diego?

Most detached ADUs in San Diego are built on monolithic slabs — a single pour combining slab and footing that works well for level or mildly sloped sites with standard soil conditions. Sites with significant slope, expansive soil, or unusual drainage may require a stem wall foundation or grade beam. The building department's requirements and the structural engineer's plans determine the final answer for each project.

How does San Diego soil affect foundation construction?

Soil conditions vary significantly across the county. Coastal and sandy-soil areas are generally more stable. Inland cities — El Cajon, Santee, Escondido — have clay-heavy soil that expands when wet and contracts when dry, which puts more movement stress on slabs and footings over time. We assess soil conditions at the site and adjust base prep, reinforcement, and footing depth accordingly.

How long before framing can start after the foundation is poured?

Concrete reaches adequate strength for framing loads in approximately 7 days under normal San Diego conditions. Full cure takes 28 days. The project schedule — and whether the building department requires a final foundation inspection before framing — determines the practical timeline. We coordinate that with the general contractor or owner so the schedule is clear before we pour.