Viaplast® is an innovative "semi-adhesive" waterproofing process for engineering structures with concrete decks. It is made up of a cold-laid bituminous sheet and a specially formulated sand asphalt overlaid with a wearing course. Viaplast® combines fast execution, savings as a result of reduced wearing course thickness and efficiency. By allowing the water vapour from the structure concrete to circulate below the sheet, it eliminates "blistering".