What are parapet walls?

According to Wikipedia, “A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a fire wall or party wall”.

Why waterproof parapet walls?

A parapet wall left with no waterproofing can cause moisture ingress through walls and at the edges of interior ceilings. Many complaints about leaks in interior spaces originate from inadequate waterproofing over parapet walls. Often water ingress from parapet walls is visible through clear blistering of paint in interior spaces. The presence of a white powdery substance called efflorescence further indicates moisture in walls; this is a result of the lime in cement coming to the surface. In the case of parapets the moisture is located fairly high up on the wall, this must not be confused with walls that have damp problems in its entirety, where a uniform spread of damp is present.

Checking for waterproofing problems on my parapet wall

A parapet wall may also show signs of inadequate waterproofing if the exterior face of the wall is riddled with hairline cracks and sometimes larger cracks. A parapet wall acts as a barrier to the wind and other elements, if not properly waterproofed it can allow moisture into a building. Parapet walls are the meeting point for roof sheets and waterproofing membranes, and so the parapet wall waterproofing system must be applied taking into account the type of flashings and counter-flashings to be encountered as a result of terminating roof and waterproofing systems.

Anker Projects has proven expertise in the waterproofing of parapet walls in the context of a holistic waterproofing and roofing solutions