Precast concrete refers to any type of concrete structure that is manufactured at a plant and transported to the construction site. In contrast, regular concrete structures are normally molded, poured, and cured on-site. Precast concrete is used in a variety of projects ranging from home landscaping all the way to massive building and bridge construction. It is being used more and more in home and building construction because it is more readily available than ever before, and provides quality and uniformity that may be lacking in on-site concrete work.
There are many advantages to using precast concrete structures over on-site concrete construction. It is made at a plant, under controlled conditions, and undergoes routine quality control inspections. The molds used to create precast structures can be used over and over; on-site concrete molds are typically built once and discarded. Because the plant specializes in concrete, they can usually offer a variety of shapes, sizes, thicknesses, and finishes for your concrete structure. When you consider the cost of labor for a team of skilled workers pouring concrete on-site, precast concrete may save significant money on the cost of your project.
Any number of products can be made using precast concrete. Municipalities make extensive use of precast pipes for wastewater disposal and treatment. In areas that are prone to tornadoes, storm cellars made from this type of concrete are a simple and fairly economical way to provide a safe shelter near your home. New home construction often makes use of preformed concrete walls, which saves time because the concrete is already cured at the factory. The walls arrive at the construction site ready to install.
Precast concrete walls can be single or double thickness. A single thickness wall provides durability and some soundproofing. In addition, a double-thickness wall can provide insulation and extra strength for load-bearing walls, or for areas where severe storms require sturdier home construction.
Double-thickness walls are also called sandwich walls because they are made from two layers of concrete with a layer of insulation sandwiched in between. Because both the concrete and the insulation can be poured and molded to exact specifications, double-thickness walls are made with door and window openings already molded in. There is no need to cut these openings into an existing wall. Precast concrete walls are sometimes manufactured with electrical outlets and telecommunications ports already installed. Once they are transported to the construction site, they simply need to be assembled.
Most companies in the U.S. that manufacture precast concrete products are regulated by both government agencies and trade associations that set minimum acceptable standards for quality. This assures the consumer that they are buying a quality product that has been properly cured, tested, and inspected.