The foundation is often viewed as the most important part of a dwelling since it supports the entire home, and its contents.   Cinder concrete blocks are commonly used for housing foundations and porch foundations.   There is some controversy about using cinder blocks over poured concrete for basement foundations, but a key realization is that concrete block is made from poured concrete.   The main ingredients in concrete block and poured concrete is sand, Portland cement, and gravel.   The only difference between the types of concrete is the size of the gravel used in the mixture.   The concrete block mixture uses a much smaller gravel size.

The typical concrete block foundation is not solid since the concrete blocks that are used to build block foundations are hollow.   When concrete blocks are stacked on top of one another, you can look down through the center of the foundation. After the concrete blocks are laid, the voids can be filled with a cement-based mortar or poured concrete that contains small pea gravel to make the foundation walls nearly identical to poured concrete walls.   Also, the presence of reinforcing steel dramatically increases the overall strength characteristics of masonry or concrete.   Lastly, remember that a concrete wall is not waterproof unless a waterproofing system is applied, such as parging.