In post-occupancy investigations, almost no leak originates from the field of a membrane. Failures concentrate at five details: pipe penetrations, upstand terminations, construction joints, drainage outlets and the transition between horizontal and vertical planes.
Each of these needs a drawn detail before work starts, not a site decision by an installer at four in the afternoon.
We require a flood test with a documented 48-hour hold before any screed or backfill covers the membrane. It is the cheapest insurance in the whole project.
Where a leak is later reported, the flood-test record instantly separates an installation defect from subsequent damage by a following trade — which turns a dispute into a repair.