May 18, 2022 – In many co-ownerships, the creation of common spaces in the form of rooftop terraces on underground parkings enhances the collective living space. These rooftop terraces, considered essential components of modern architecture, present various maintenance challenges. While offering numerous benefits, they can be the source of structural problems requiring significant repair and maintenance interventions. When signs of deterioration appear, it is crucial to act quickly to avoid potential more serious damage.
Design: Rooftop terraces and underground parkings share a key structural feature: a concrete slab that serves as a separator. To ensure the watertightness of this slab, a waterproofing membrane is applied, playing a vital role in preserving the integrity of the concrete slab. The lifespan of this membrane is generally similar to that of a traditional roof, which is about 25 years. However, cracks can appear on these concrete slabs, often without immediate consequences.
Membrane alterations: Symptoms: Several signs can indicate the deterioration of the waterproofing membrane, such as the presence of cracks of different sizes, the appearance of moisture along these cracks, and the formation of calcareous salt deposits, resembling stalactites.
Structural slab alterations: Symptoms: The presence of moisture, seeping through the cracks, can cause corrosion of the reinforcing steel rods, threatening the structural integrity of the concrete slab. This corrosion can lead to spalling and degradation of the concrete, affecting its load-bearing capacity and, consequently, the safety of the structure.
Corrective measures: It is essential to adopt corrective measures taking into account certain fundamental principles, such as protecting the concrete slabs against moisture with an effective waterproofing system. Waterproofing membranes, whether applied on vertical or horizontal structures, must be continuous to ensure total watertightness.
Conclusion: Effective management of rooftop terraces and underground parkings in co-ownership requires constant vigilance and prompt intervention in case of signs of deterioration. The preservation of these spaces requires not only regular maintenance but also a proactive approach to waterproofing and structural problems. By adopting rigorous maintenance strategies and implementing repairs at the first signs of deterioration, it is possible to ensure the durability and safety of these valuable spaces for co-owners. 
For any additional information, please do not hesitate to contact us.
Georges Fallah, Architect
Member of the Quebec Order of Architects (MOAQ)
President of G.A.P.Immeubles inc
Tél. : (514) 946 8807
Fax : (450) 478-4932
Courriel : [email protected]
The columns express the personal opinion of their authors and do not in any way commit the responsibility of the site's publisher, CondoLegal.com Inc. The content and opinions expressed in a column are solely those of the author.
