Monolithic Foundation Construction Research

We have avoided this topic for some time. Let’s face it, home foundations are as exciting as talking about your grass growing. When it comes to basement floors there are two types of foundations – Monolithic and Standard. Some folks will call the monolithic, a floating foundation, while others will call the standard, a footer foundation. Regardless, here’s the quick definition of both.

• Monolithic slabs are foundation systems constructed as one single concrete pour that consists of a concrete slab with thickened portions of the slab under load bearing walls and all perimeter edges that take the place of footers.
• Standard slabs are foundation systems constructed in three components; a footer to transfer load to the underlying soil, a masonry foundation and a poured slab.

Monolithic foundation

Monolithic foundations are very easy to build. These can be done all in one day.

Monolithic foundations (MF)

Monolithic means "all in one pour".  This means that the footings and the floor are all poured in one shot.

How deep

A monolithic foundation is only 12 inches deep.  This is measured from the bottom of the hole to Monolithic Definition: “Having a massive uniform structure that does not permit individual variations”, according to, Funk & Wagnall’s Standard Dictionary.

With proper reinforcement this is the foundation of choice for cost, speed and structure. It is also the easiest to convey. When the concrete is poured all together and backed up with enough steel so as not to separate, it is by far the best choice. There are no seams or cold joints unless there is joint reinforcement. There is no use of precast footings.

Monolithic: Definition of monolithic slab foundation: poured concrete footings and the concrete floor are poured simultaneously as one continuous system.

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  Excavation and concrete forms are used to form the footing and foundation wall portions of the structure. Supported slabs - (see slab on grade illustration above)
  
  Definition of a supported slab foundation: a poured concrete slab is supported on footing/foundation/pins. Vulnerable to hairline step cracks in block walls that rest on the slab; (FL per Mark Cramer). Cracks that are hairline to 3/16 common at the top of slab elevation.

Said of a concrete pavement or floor whose surface layer is formed integrally with the slab below.