A structured sequence from initial flood test to filmed final verification. Each step serves a specific purpose in establishing the condition of the terrace and confirming the outcome of the intervention.
Visual inspection of a terrace surface can identify obvious damage — visible cracks, blistering, or detached membrane sections. However, it cannot determine where water actually enters the building or how it travels through the slab before becoming visible as a leak inside the apartment below.
The controlled flood test addresses this limitation directly. By retaining water on the terrace surface and monitoring the ceiling of the space below, it is possible to map the actual path of water infiltration — including horizontal travel through the slab that would be invisible to any surface inspection. This information shapes the entire scope of the subsequent intervention.
The process begins with a thorough visual inspection of the terrace. The existing membrane condition, drainage points, parapet junctions, pipe penetrations, and any visible damage are documented. The condition of the ceiling in the apartment below is also assessed to understand the current pattern of infiltration. This establishes the baseline before any testing begins.
Drainage outlets on the terrace are temporarily sealed and water is introduced to create a controlled flood condition. The water is retained at a defined depth for a set period — typically several hours. During this time, the ceiling and walls of the space below are monitored for any signs of moisture, staining, or active leakage. The location and timing of any infiltration that appears is recorded. This data establishes exactly where the waterproofing system is failing.
Based on the diagnostic findings, the existing waterproofing system is removed in full. This includes the membrane itself, any protective screed or mortar bed above it, and any pavers or tiles that form the walking surface. Complete removal is standard practice because partial repairs applied over a compromised substrate typically fail again within a short period. Removal also allows a thorough inspection of the structural slab for any cracks, deteriorated concrete, or other issues that need to be addressed before waterproofing is re-applied.
With the slab exposed, any structural repairs identified during removal are completed. The surface is then prepared for the new membrane — cleaned, primed, and graded. Mortar is used to establish correct drainage slopes, directing water toward the designated drainage points. Minimum slope gradients are established according to the geometry of the terrace and the location of its drainage outlets. This step is performed before any new membrane is applied and is not treated as optional.
The new waterproofing membrane is applied over the prepared and primed substrate. Coverage extends continuously across the entire terrace surface and up the parapet walls to the required height. All drainage collar connections, pipe penetrations, expansion joints, and perimeter edges receive detailed treatment to ensure continuity of the waterproofing layer at the points most susceptible to failure. The membrane type and thickness are selected based on the specific conditions of the terrace.
After the membrane has fully cured, a second controlled flood test is conducted under the same conditions as the initial diagnostic. The drainage outlets are sealed, water is retained at the same depth for the same period, and the space below is monitored for any signs of infiltration. The absence of any moisture or staining in the space below confirms that the new waterproofing system is performing correctly. The entire test — from water introduction to monitoring and result — is recorded on video.
The video recording of the final flood test, along with a written technical report documenting the initial condition, the interventions performed, the materials used, and the test results, is compiled and delivered to the building consortium. This documentary package serves as the official record of the completed work and can be referenced in future maintenance planning, in administrative meetings, or in any proceedings related to the condition of the terrace.
Terraces in Mendoza experience significant temperature variation between seasons and between day and night. The membrane selected must accommodate the thermal movement of the slab without cracking or delaminating. The degree of sun exposure also affects the UV resistance requirements of the surface finish.
Accessible terraces and walkable rooftops receive foot traffic that standard non-accessible roofing membranes are not designed to withstand. The waterproofing system for a transitable surface must include either a membrane rated for foot traffic or a protective layer above the membrane that distributes the load.
The number, location, and condition of existing drainage outlets affects both the slope correction work and the detailing of the membrane around each drain. Blocked or deteriorated drains are addressed as part of the intervention since they directly affect the performance of the new waterproofing system.
The condition of the concrete slab beneath the membrane affects the preparation work required before waterproofing can begin. Cracks, spalled concrete, or carbonation of the surface require treatment before a new membrane can be applied with confidence in its long-term adhesion.
Structural expansion joints in the slab require specific treatment in any waterproofing system. The membrane cannot simply bridge a joint without accommodation for movement — specialized joint covers or flexible membrane details are required at these locations to prevent failure as the structure moves.
Different membrane systems have different cure time requirements and temperature or humidity restrictions for application. The scheduling of work takes these requirements into account to ensure the membrane is applied and cured under appropriate conditions.
Contact us to describe your building's terrace situation. We can discuss the diagnostic process and arrange a site visit to assess the condition directly.