What if the basement has under-pinning or piling?

The use of contiguous / secant piling and diaphragm wall construction techniques to construct retaining walls is common in large commercial basement projects. The nature of these construction techniques is such that the only practical option is to apply waterproofing systems to the internal face of the retaining wall. Choosing which system to use will depend on a number of factors including site conditions, drainage options, and personal preference. There are three options available: Oldroyd Cavity Drainage System, Vandex Cementitious Waterproofing Slurry or a Combined Waterproofing System (http://www.safeguardeurope.com/applications/contiguous_secant_diaphragm.php).

For a good example case study of basement waterproofing using secant piled construction, please click the following link: http://www.safeguardeurope.com/case_studies/waterproofing-basement-secant-piled-london.php