Expansion Joints in Deck Waterproofing Systems
SourceStructural expansion joints that interrupt plaza and traffic bearing waterproofing membranes are often a source of leakage. Most joint seals in plaza type waterproofing systems are “buried,” making them difficult and expensive to maintain. Exposed joint seals in traffic bearing waterproofing systems are subject to severe loading conditions, such as vehicular traffic, but are generally accessible.
This paper presents design concepts for waterproofing expansion joints in building decks. We review assemblies commonly used to waterproof expansion joints and we examine several design concepts. Membrane/waterproofing continuity across joints and joint maintenance are of particular concern. An estimate of the joint movement is necessary to select a joint seal. Adequate drainage away from the joints remains the most important design consideration