A concrete slab is a familiar structural component of modern buildings, made up of a solid, flat, even surface made from coarse cast concrete. Concrete slabs vary in thickness, width, and length. The longer the slab, the greater the weight it can safely bear; conical-cut concrete slabs are used where weight is an issue. Concrete is formed at a construction site by mixing mortar and curing it in a machine, then scooped into long, rectangular blocks. Once these blocks are sturdy enough to handle the weight of the concrete and weathering, they are placed in an overhead slumping position.
The two basic types of precast concrete slabs are man-made and natural. Man-made slabs are molded on site using a large roller and concrete mixture. They can be custom curved, wide or long, and may be stamped with designs or engraved with logos. Natural slabs are crafted from natural materials that have been shaped and refined to specifications on the manufacturing line. These slabs are also premolded, but their parts are cut and shipped in large sheets.
Concrete slab thickness is an important factor in the cost of an installation. In general, the thicker the slab, the more expensive the installation will be. In many cases, the decision to use a thin slab is based on the builder’s or contractor’s lack of experience in constructing heavy slabs. Many construction projects, however, do not require a thick slab due to their low weight. Another common reason for thin concrete slabs is to save on the time and effort required to level and prepare areas for walking ways, parking lots, and exterior pathways.
The amount of thermal mass that a slab contains is another factor that builders consider when choosing a flooring product. Thermal mass is the difference between how much heat passes through a slab when it is cold and how much heat moves through when it is hot. Thin concrete slabs contain a high amount of thermal mass, which makes them an excellent choice for cold climate applications. More thermal mass means a larger volume of water and oil can pass through the same space, which means a greater potential for chemical spills. For this reason, the thermal mass is typically recommended for cold climate applications and thinner concrete slabs are generally recommended for hot climates.
Other important factors to consider when selecting a flooring product are the thickness and thermal conductivity of the slab. Each concrete slab has its own unique set of unique thermal properties. It is important to know what each property is and how it affects the building as a whole before selecting a flooring product. To ensure that the thermal conductivity and thermal mass are comparable, concrete slabs are usually scored in similar manners.
For example, a slab that is stamped with a three-dimensional grove is more thermal conductive than one that is simply laid with flat slabs. The grooves make the surface of the concrete slabs cool more quickly, reducing the rate at which heated air and other liquids flow through the slab. A three-dimensional grooved concrete slab may also be able to reduce sound pollution, as particles that may be carried through air during construction are slowed by the grooves upon being deposited in the building. It is possible to have a thin concrete slab poured on top of existing slabs. If a thin slab is poured directly over an existing slab, the existing slab may need to be removed and inspected for cracks before the new concrete slabs are laid. This is because the thickness of the concrete slabs can affect how the structure of the structure or the entire building is built.