High Exposure Polycarbonate Projects: Commercial contractors come to us with various polycarbonate projects. Custom built polycarbonate structures are often a wise choice. The Sundance Supply approach is a Multi Wall Lexan Polycarbonate sheet covering and the Base & Cap Installation System. The customer provides the frame and remaining building components, for an elegant addition solution. Together this approach provides a watertight, attractive and long life solution, at a fraction of the cost of prefab systems. Substantial savings can be achieved.