Common waterproofing mistakes

Waterproofing is not just a coating on a flat surface; corners, junctions and pipe penetrations are part of the system.

What is the key practical principle?

Poor substrate preparation, insufficient coverage or starting the next trade too early increases leak risk.

In bathrooms and terraces, correct falls are as important as the waterproofing membrane itself.

Which details and mistakes increase risk?

The substrate must be sound, clean and suitable for the selected system. Dust, weak render, moving cracks or excessive moisture reduce adhesion; preparation may include priming, crack repair and reinforcing corners.

The most sensitive locations are corners, pipe penetrations, thresholds and drain connections. These details often require flexible tape or collars because simply applying more of the main coating does not replace correct junction treatment.

How do you make a practical decision?

Correct falls should be designed together with waterproofing in wet areas and on terraces. Standing water increases stress on joints and details. Where appropriate, a controlled water test before final finishes can provide an additional quality checkpoint.

The next trade must not damage completed waterproofing. An accidental hole or cut can become the weak point of the entire system, so membrane protection and photographic documentation of critical details are part of practical quality control.