We use silicon coating on the out face to increase mecanic resistance and water repealance. The inner face is finished with PU coating that allows us to tape all our seams. The Samaya2.5 vestibule Nylon reachs a waterproofness of three thousand mm. The guy lines have a Dyneema core. We add snowskirts on the floor to guarantee the best stability of the tent. They are designed with a Nylon thirty denier to be more resistant.