The three major types of inground pools are fiberglass, vinyl and concrete pools. They offer a variety of features and come in a range of prices. For concrete pools, the creativity available in building concrete pools makes them the most popular option, even though they are the most expensive to build of the three styles. Concrete pools utilize quick-dry concrete to fill in the area that has been excavated for the pool. After work begins in filling in the area, it must be completed in short order, approximately 30 minutes. The base of the pool needs to conform to a prearranged design, but the stairs and entry areas of concrete pools can be decided on in a freehand manner. Maintenance of concrete pools can be costly because the concrete starts to crack and stain and might require a refinishing of the pool surface.