This type of swimming pool is made of concrete materials popular they also finish with plaster (a mixture of cement with marble of sand). This type of pool is very popular in the United States. And a difference of gunite pools is poured from the manufacturing technique. The manufacturing process by spraying gunite material on the framework of concrete poured while longer because the manufacturing process using conventional means. Build a swimming pool behind the house may not be an easy job. That if you want to build a great in-ground pool. Different but if you want to build an above ground pool in your own backyard. Swimming Pool.