Seal coating has no structural value in that it does not provide a new wearing course but instead protects existing roadway surfaces and infrastructure by sealing in the oil, sand (or fines) and large rock aggregate that must be present at all times to keep a good roadway. Over time, sand will travel out of the mix if not sealed, and then large pieces of asphalt will start to pop out. To keep that from happening, liquid is spray applied through a two-coat process to hold the elements in place. Another type of seal coat – FOG seal – uses a different type of oil but is designed to settle and sit down around the big rock and hold sand down instead of focusing on keeping the fines in place. ViaSun utilizes a wide variety of products in seal coating, including MTR, PMM, TRMSS, and Liquid Road.