Terrazzo is one of the world`s oldest construction materials and one of the most permanent of all flooring materials. It consists of marble or stone chips set in mortar, which are then polished to form a hard, tough, continuous surface that stands up to all kinds of abuse. Even so, the surface contains tiny micropockets that provide sites for the growth of microbiologicals. For that reason, it is not satisfactory for pharmaceutical or biotech cleanrooms. It may be used in some electronics applications because it does not generate dust particles and is so durable that repairs are seldom necessary.

Vinyl sheet provides a continuous, impermeable surface that is smooth, easy to clean, and does not release particles into the air. It is used in many pharmaceutical applications; also, desirable electrical properties can be designed into the material for electronics applications. However, if the room is larger than the width of the rolled sheet goods, there will be a seam which can offer sites for the growth of microorganisms. Vinyl sheet is subject to wear, and eventually needs to be replaced–a costly item in any cleanroom. It is also not very chemically resistant and, therefore, cannot be used where chemical containment is required.

Vinyl tile is similar to sheet goods, except that seams between the tiles make cleaning difficult and offer many sites for microorganisms. Vinyl tile is widely used in electronics industry cleanrooms, but only where there is no spilling or splashing of chemicals onto the floor.

Paint is commonly applied to industrial concrete floors to retard dust and protect surfaces against wear and mild chemicals. High performance epoxy and polyurethane floor coatings are relatively easy to mix and apply. (These products should not be confused with flowable engineered copolymer flooring materials.) They adhere well to properly prepared concrete surfaces and effectively extend the useful life of the concrete. However, because painted floors wear and sometimes peel, they also release unacceptable amounts of dust, and provide numerous opportunities for microscopic growth. Even high performance coatings are generally unsatisfactory for cleanroom floors.

Engineered copolymer toppings for concrete meet a range of cleanroom floor criteria, including resistance to corrosive chemicals, abrasion, and impact. Various electrical properties and levels of slip resistance can also be incorporated into the formulations. An engineered copolymer material forms a seamless, pore-free surface able to resist highly corrosive chemicals, including sulfuric acid and caustic soda solutions. These materials bond tightly to concrete, whether in the form of thin-film coatings of 16 to 60 mils or high-build toppings, which can be applied to a thickness of 250 mils (1/4 inch).