Most high-rise structures and other large commercial developments are often designed with deep basements. Since the entire load of the superstructure is transferred to the sub-structure, this becomes the most critical part of the whole structure and needs to be in good condition, durable and sustainable in the long run. Normally, substructures are often subjected to
- High level of water pressure
- Aggressive soil contaminants and gases
- Unequal static forces due to settlements or uplift
- Dynamic forces due to earthquakes and other structural movements
Hydrostatic pressure forces water into the building through cracks, joints and any porous substrates, causing possible major structural damage and is likely to contribute to mold, corrosion and other moisture-related problems.
Therefore, it is critical to choose the right waterproofing solutions for substructures which eventually affects the overall life of the structure and its maintenance cost over the years. Constructions can be very unorganized, especially when it is not done in one stretch – the expertise of the applicator, weather conditions and movement of materials can affect the effectiveness of the waterproofing solution chosen. Liquid applied membranes are very effective solutions but require a very meticulous application, which can sometimes be challenging for the reasons mentioned above. Therefore, sheet membranes can be a preferred choice because of their no-fuss and less time-consuming application process.
Factors to consider when choosing a sheet membrane
Sheet membrane systems are reliable and durable waterproofing solutions that can meet the requirements of the most demanding below-ground structures, including those exposed to extreme water tables, aggressive ground conditions and stresses. There are different kinds of sheet membranes that are available in the market, made of varied materials and of different properties like PVC membranes, HDPE membranes, TPO membranes, APP or SBS-modified bituminous membranes, etc. One must choose wisely based on the location of the structure and the kind of waterproofing it needs.
Key properties to be considered while choosing a sheet membrane for substructure waterproofing are
- High degree of water tightness
- Higher Tensile Strength, Tear resistance and Puncture resistance
- Higher elongation to accommodate structural movements and stresses.
- Resistant to soil contaminants, aggressive chemicals and gases
- Faster application without any curing/waiting times
- Longer service life of the waterproofed basement or below-grade structure.
ECMAS offers different types of sheet membranes such as ECMASHIELD HDPE, ECMASHIELD PVC and ECMASHIELD SA for substructure waterproofing. These are available in a variety of technical specifications as per project requirements.
ECMASHIELD HDPE is a pre‐applied, chemically resistant and fully bonded HDPE (high-density polyethylene) waterproofing membrane system for underground concrete structures. This multilayered, composite membrane is made of a tough, resilient and high strength HDPE waterproofing membrane along with pressure-sensitive adhesive and a trafficable, weather and dirt resistant non-absorbent coating and a release liner. It fully bonds with the freshly poured concrete against it and forms a continuous and permanent bond to prevent water ingress & migration at the interface of the membrane and structural concrete. HDPE membrane is an ideal waterproofing solution for deep basements and other UG structures in high water table areas.
ECMASHIELD PVC is a loosely laid, non-reinforced geomembrane made of flexible polyvinyl chloride with a thin yellow colour signal layer. The signal layer helps in easy visual detection of the damages caused to the geomembrane during the installation and during the successive works. It offers unique heat-welded seams allowing pressure testing of joints for complete water tightness. Due to its excellent tensile strength, flexibility, tear-resistance, and chemical & plant root resistance properties, this membrane is most suitable for Heavy Duty Waterproofing of deep basements in high water table areas and waterproofing of Road, Railway and Metro tunnels and other UG structures.
ECMASHIELD SA is a self-adhesive (peel & stick type), factory-made, cold applied, easy to install waterproofing membrane designed to meet high mechanical performance. ECMASHIELD SA is made from Bitumen/asphalt compound modified with SBS and high track resins, stabilizers and inert fillers to improve cold weather flexibility, and upper surfaces are finished with a cross-laminated high-density polyethylene (HDPE) film. This membrane is very suitable for waterproofing substructures such as foundations and retaining walls.