Waterproofing failures rarely begin in the middle of an uninterrupted membrane. They usually start at a detail—where materials change direction, services penetrate the system or an edge is not terminated correctly.

1. Upstands and level changes

Membranes must rise high enough at parapets, kerbs and door thresholds to remain above the expected water level. Sharp internal corners should be prepared with fillets or compatible reinforcement so the membrane is not forced across a weak point.

2. Drains and penetrations

Floor drains, pipes and outlets interrupt the waterproofing plane. Each penetration needs a compatible collar, positive connection and enough working space for proper application. Sealant alone is not a substitute for a designed membrane detail.

3. Movement joints and terminations

Building movement must be accommodated rather than restrained by a brittle detail. Joint systems, edge bars and terminations should match the expected movement and exposure.

At exposed edges, the termination must prevent water tracking behind the membrane even after protective layers are installed.

4. Substrate preparation and protection

Dust, laitance, standing water and poorly repaired cracks can compromise adhesion. Once tested, the completed membrane also needs protection from following trades, reinforcement and screed works.