When you think of a home's foundation the parallels can be drawn to a human being. The legs and feet are the foundation and footing, respectively, and maintain the integrity and stability of the body. The footing of the home, like feet, spread the weight over a greater area and prevents sinking and shifting.

In years gone by foundations were made from stacked stone which held together by weight and pressure. Because most of them were built up to 4 feet thick many of these interlocking stone foundations are still bearing weight today.

Even if a home is built on a pad there has to be some sort of stabilizing feature to accept the weight. In this case the foundation would be not as tall as one with a basement and the pad would "float" in between. Sometimes the pad and footing are joined without a cement foundation. A supporting footing is often placed in the center to accept more weight from a load-bearing wall. This form of building does not require the amount of cement or forms required in foundations.

Basic Home Foundation

Compaction: In most areas foundations are dug out of the soil for a basement however in many parts of the country they are blasted out of solid rock. In the latter case footings are not required because, in essence, the whole rock face underneath the home becomes a very stable footing. But usually, an excavator digs down to a required depth and then a 6" gravel base put down and compacted. This is then tested with a compaction instrument to ensure that the base is stable.

Footing: The footing is wider than the foundation wall and is poured usually 12" below the frost line for the area. This makes sure that any expansion and contraction during the freeze-thaw process does not affect the home's stability. Horizontal reinforcing bars are tied into the forms before the cement goes in and vertical rebar tied vertically so that it can hold the concrete foundation. Sometimes, if the home is being built on a hill, "step footings" can be poured.

Foundation: Building a foundation usually begins with wooden forms. Steel reinforcing bar is tied to the uprights from the footings and then cement is poured. Some foundations are made from cement block and the vertical bars go through the holes in the block for support. The the holes are filled with cement for stability.

Monolithic Slab

In cases where there is no basement the floor pad can be poured at the same time as the footings. A single layer of concrete the thickness of the floor is poured, but the slab is much thicker at the edges where the exterior walls of the home will sit. Reinforcing rods strengthen the edge and this is tied into the heavy mesh wiring that reinforces the pad. In addition, extra foting areas can be put int to support load-bearing walls. This form of foundation works best in warmer climates without a worry of frost in the ground.

Insulated Concrete Forms (ICF)

These are basically blocks of foamed polystyrene (coffee cup material) which are stacked, reinforced with steel bars and then filled with 6" of concrete. The blocks are stacked like large children's plastic blocks and, after the cement cures, the foam becomes the insulation for the home. ICF can be used from the footing to the gable and works great in cold areas because it keeps the frost away from the cement and steel.

Preserved Wood Foundations

In dryer areas many homeowners opt for a pressure-treated wood foundation. This timber gets more than the required dosage of preservative than usual wood which, unlike cement, will not let moisture through the walls. It also makes a warmer wall without condensation so there is no basement "musty smell."

Of course the building costs are less because cement costs more than wood and there are no forms to set up and take down. In addition, the livable space is increased because with wood it doesn't matter if the space is subterranean because the walls are not porous. In addition, the wood foundations can be installed in almost any type of weather. The primary concern with a wood basement id insects, mainly termites but properly-treated wood won't decay and this eliminated the food source for termites.

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