If you are not familiar with PreTak, it is a 46 mil (1.2 mm) thick composite membrane, engineered for pre-applied waterproofing in horizontal underslab and vertical shoring wall applications, commonly known as blindside waterproofing.
T-lap seams, where three layers of membrane overlap at a perpendicular intersection, present a more challenging scenario for maintaining watertight integrity under hydrostatic pressure.
EPRO developed a new and novel approach, modifying the ASTM D5385 to prepare test specimens which include overlapped membrane longitudinal laps and end laps, forming a T-lap seam intersection. These test specimens were then tested to the ASTM D5385 standard with incremental increases in hydrostatic pressure to test the overall seam assembly hydrostatic pressure resistance at the T-lap seam.
Our results are presented in a white paper examining this testing approach targeting the T-seam, proving the performance of PreTak pre-applied sheet waterproofing membrane against a modified ASTM D5385 method of testing.
Download the white paper below.