Foundations
Every house has a foundation. The real question is what exactly is a foundation? A foundation is the base of your building, that always includes footings. Footings are the supports that your house sits on. Foundations play a key role in the structure of your house because without them, your house could potentially slide away. WIth our harsh winters as well, frost may sneak up under the floor and crack the bottom floor, often cement. Footings play a key role in foundations, and are often considered the "shoes" of your house, where everything sits.
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History of Footings
Notice the Difference between the two different types of footings and how much more economical it is for concrete footings.
Courtesy of Home Building and Renovating and their affiliate photographers. (see works cited page)
Believe it or not, our local history and settlers occupations played a key role in the beginning of footings. The main occupation of the day was either farming or logging. When the farmer plowed his field, he began throwing rocks off to the side. Eventually, he put them to use in the creation of footings. At the time, footings consisted of cement and the discarded socks. With cement acting as a binding agent, these strong structures were able to hold the weight of the farmer's house; however, despite the great engineering feat, there were drawbacks. For example, the rocks were often too big and frost would grab them. As a result, the foundations would crack and begin to crumble and would have to have maintenance performed periodically. Another was that there was air inside of
Today's foundations have been refined, thanks to our mighty friend; chemistry. After studies on the molecular effect on frost, a conclusion was drawn that to make the cement-rock bonds stronger and more frost-resistant, the rocks would have to be busted up and much smaller to evade the effects of frost. The proportion of cement to rocks changed and thus formed concrete. Concrete is a mixture of gravel and cement. When this change occurred, a new technology happened to be produced as well.
Another challenge faced with the antiquated foundations was that air was trapped within the footing itself, which expanded and contracted, causing additional cracking. Thanks to studies on the gas laws, chemists were able to reach a decision that minimal air was to be incorporated in the footing. The real question that was imposed was how?
The answer was the emergence of a new tool, the concrete vibrator. This tool is merely an air hose that vibrated on the end of a motor. You can see in the image on the left. When the hose vibrates, it forces the air bubbles to the top of the concrete, eliminating the minute air gaps that caused additional cracking. This new technology reduced air bubbles from the size of a marble to the head of a pin. WIth these air bubbles gone, cold air can't turn warm and expand with its moisture from the concrete and crack.
Thanks to this new technology, foundations, and basements shifted from stone, which was high-matinence-and time consuming to create, shifted to rebar and concrete. Rebar is the skeleton that gives concrete it's support. It is basically in any concrete structure that you see.
Courtesy of Bosch photography and productions 12.19/17 (see works cited)
Concrete became the main foundation because it was quick and easy to install as well as low maintenance, and its sustainability is very high. (see sustainability tab) Everybody in our area that builds a house has concrete footings and often a concrete basement. Another method is cement block walls. Cement blocks re-place concrete in this instance and are often found in older homes because they were cheaper than concrete at the time. Regardless, a cement slab is poured for the floor, instead of stone, like the original foundations.
When you look back on the evolution of foundations of homes, you see that our economy played a very big factor in the way foundations came about. From the annoying rocks in farmer's fields to the support of your home, rocks were the strength of our homes for a long time. Then by applying the gas laws and looking at strength of concrete products at a molecular level, concrete became very popular. Thanks to chemistry, there is a very long life-span on concrete and its strength is perfect for holding any house. The chemistry behind concrete and cement is the same regardless. An exothermic reaction occurs when water is added to a powdered mixture of cement and rock, soon to be concrete. Hydration occurs and the concrete hardens after it is trowelled and vibed. Hydration is a chemical reaction in which the major compounds in cement form chemical bonds with water molecules and become hydrates or hydration products.
Sustainability
When considering these options for foundations, you must consider their sustainability, the amount of time that they will last. You will also want to have the cheapest item, especially when your bill may be thousands of dollars. Many people balance the cost; however, every foundation now is constructed from concrete and sometimes block walls. Concrete is by far the cheapest and most sustainable building material mentioned on this page. It is projected to last hundreds of years with the help of reinforcement bar. Stone foundations last about 100-150 years before they need serious maintenance fence. Block walls are usually equable in price to poured cement walls; however, they are only projected to last about 150 years. They are not all bonded, only on four joints, which makes them weaker than cement as well.