Concrete Slabs for Steel Buildings

Once you find a steel building that suits your needs, we recommend taking the plans from the steel building manufacturer you are considering to your local building department. This ensures you understand the specific type of concrete slabs required for your structure, particularly if you are planning a frost protected foundation.

There are several types of concrete slabs that can be poured for steel building construction, and your building department will typically require one of the following options:

a. 6" slab with an 18" thickened haunch (edge) (monopour)

b. 6" slab with an 18" thickened haunch and insulation (frost protected shallow foundation) (monopour)

c. Full 4' frost wall foundation and slab

These options are listed in order of price, from lowest to highest. The thickened haunch with notch edge is often mandated not only by the town but also by the steel building company, as they require the thickened edge to properly bolt their building.

The concrete slab is typically poured 3 1/2" wider on all sides for a 'Drop Notch Edge,' allowing the building to sit slightly inside the slab. The wall sheathing will hang down below the slab into the 'notch,' effectively preventing water intrusion.

Additionally, optional insulation such as foam board can be installed beneath and around the slab to enhance frost protection, a practice often implemented when the building is heated.