A house's foundation is what determines if it will stand the test of time. A strong foundation can last 100 years or more. A weak one can crack and shift allowing water seepage, insects infestations, and complete failure during an earth quake or other natural disaster.
The first step to ensuring a strong foundation is using good materials. Concrete begins with limestone sand and other ingredients. These components are processed using specialized vertical conveyor belt systems and mixing equipment. If the proportions are off, or the materials are of poor quality, the concrete can be weakened and prone to crack.
Before the concrete mixture is poured, the site has to be readied for it. Space must be excavated, and allowance made for proper thickness of the foundation. If there will be a basement, egress basement window wells, plumbing, and electric wiring must be planned for. Framing windows and stairs is an intricate process in itself. To reinforce the concrete and increase tensile strength of the foundation, steel rebar is placed in the concrete molds. Building codes require that all these steps be taken and this work must be inspected before the concrete is poured.
When the site is ready for the concrete, it is normally poured straight out of the back of a concrete truck. Construction workers make sure it is poured evenly and tamp it down to avoid bubbles. This process can take several days depending on the size of the foundation.
Concrete foundations for buildings have been in use since the Roman Empire. But new processes and more efficient bucket elevators make today's concrete stronger than the Romans would have dreamed. And in the process this new concrete has allowed us to build ever taller buildings, bigger cities, and more secure homes of all sizes.