Slab and footing, one pour.

A monolithic slab foundation combines the floor slab and the perimeter footing into a single concrete pour. The edges of the slab are thickened to act as the footing, which carries the load of the exterior walls. The entire foundation is placed in one operation with no cold joints between the slab and the footing.

Monolithic slabs work well for single-story commercial buildings, shops and warehouses on relatively flat sites with stable, well-compacted soil. They are not the right fit for multi-story buildings, sites with poor soil, steep grades, or projects that need a crawl space or basement. We evaluate the site conditions and tell you straight whether it is a good fit.

The main advantages are speed and the elimination of cold joints. Since everything is poured at once, you skip the waiting period between the footing and slab pours. There is also no cold joint between the two elements, which means fewer potential crack points and better structural integrity at the perimeter.

Often, yes. One pour means less forming, less labor and a faster schedule, and a single mobilization instead of two. The savings depend on the soil and the structure, so we price both approaches when a site could go either way.

The thickened edges typically range from 12 to 24 inches deep depending on the structural loads and what the engineer specifies. The interior slab section is usually 4 to 6 inches thick for commercial applications. The transition from the thickened edge to the standard slab thickness is gradual to prevent stress cracking.

For single-story commercial buildings, yes. The slab thickness, reinforcement and thickened edge dimensions are all engineered for the specific loads the building will carry. For heavier multi-story structures or buildings with concentrated point loads, a traditional footing and slab system is usually more appropriate.

Monolithic slabs need stable, well-compacted soil with adequate bearing capacity. Sites with expansive clay, fill dirt, high water tables or steep grade changes are generally not good candidates. A geotechnical evaluation helps determine whether the soil conditions will support a monolithic pour.

A grade beam is a reinforced concrete beam poured at ground level that spans between pier footings or load points. In some monolithic slab designs, grade beams are integrated into the slab to provide additional support at specific locations, like under interior load-bearing walls or at points where concentrated loads need to be distributed.