Type A Waterproofing to Existing Structures
Many of the considerations applicable to structural waterproofing design in new construction, apply equally to the design of systems for existing structures. However, contrary to new-build scenarios, there are limitations when working within the confines of an existing structure. There is typically a limited opportunity or scope to make structural alterations for the purpose of installing a given system.
Additionally, (in the case of new construction waterproofing), the designer is providing the initial or first-stage measures of protection against water ingress/groundwater. In existing structures, it is often the case that designs are provided for the purpose of remedying failures in those initial measures, to address problems with systems of considerable age in older or historic property, or to facilitate change of use.
If options are limited by the confines of the structure, it is important to understand what that structure is, and equally, the nature of any installed waterproofing measures within it which may further influence design.