Mason sand is classified as a fine aggregate, meaning it is has smaller particles of sand usually between 1 – 2 mm. Mason sand also meet ASTM regulations for masonry mortar, meaning it can be used for making mortar like cement. Mason sand is generally used for making mortar, or for home projects such as sand boxes, lining for swimming pools and volleyball courts. Mason sand is used to mix mortar for many construction purposes. Mason sand is very soft smooth sand so it is good for areas where you think that kids will be playing. The closest comparison to mason sand would be sand you find on the beach. Common uses for mason sand also include drainage systems, golf course bunkers, and deicing airport runways.